1 /*
   2  * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 // Must be at least Windows Vista or Server 2008 to use InitOnceExecuteOnce
  26 #define _WIN32_WINNT 0x0600
  27 
  28 // no precompiled headers
  29 #include "jvm.h"
  30 #include "classfile/classLoader.hpp"
  31 #include "classfile/systemDictionary.hpp"
  32 #include "classfile/vmSymbols.hpp"
  33 #include "code/icBuffer.hpp"
  34 #include "code/vtableStubs.hpp"
  35 #include "compiler/compileBroker.hpp"
  36 #include "compiler/disassembler.hpp"
  37 #include "interpreter/interpreter.hpp"
  38 #include "logging/log.hpp"
  39 #include "logging/logStream.hpp"
  40 #include "memory/allocation.inline.hpp"
  41 #include "memory/filemap.hpp"
  42 #include "oops/oop.inline.hpp"
  43 #include "os_share_windows.hpp"
  44 #include "os_windows.inline.hpp"
  45 #include "prims/jniFastGetField.hpp"
  46 #include "prims/jvm_misc.hpp"
  47 #include "runtime/arguments.hpp"
  48 #include "runtime/atomic.hpp"
  49 #include "runtime/extendedPC.hpp"
  50 #include "runtime/globals.hpp"
  51 #include "runtime/interfaceSupport.inline.hpp"
  52 #include "runtime/java.hpp"
  53 #include "runtime/javaCalls.hpp"
  54 #include "runtime/mutexLocker.hpp"
  55 #include "runtime/objectMonitor.hpp"
  56 #include "runtime/orderAccess.hpp"
  57 #include "runtime/osThread.hpp"
  58 #include "runtime/perfMemory.hpp"
  59 #include "runtime/sharedRuntime.hpp"
  60 #include "runtime/statSampler.hpp"
  61 #include "runtime/stubRoutines.hpp"
  62 #include "runtime/thread.inline.hpp"
  63 #include "runtime/threadCritical.hpp"
  64 #include "runtime/timer.hpp"
  65 #include "runtime/vm_version.hpp"
  66 #include "services/attachListener.hpp"
  67 #include "services/memTracker.hpp"
  68 #include "services/runtimeService.hpp"
  69 #include "utilities/align.hpp"
  70 #include "utilities/decoder.hpp"
  71 #include "utilities/defaultStream.hpp"
  72 #include "utilities/events.hpp"
  73 #include "utilities/growableArray.hpp"
  74 #include "utilities/macros.hpp"
  75 #include "utilities/vmError.hpp"
  76 #include "symbolengine.hpp"
  77 #include "windbghelp.hpp"
  78 
  79 
  80 #ifdef _DEBUG
  81 #include <crtdbg.h>
  82 #endif
  83 
  84 
  85 #include <windows.h>
  86 #include <sys/types.h>
  87 #include <sys/stat.h>
  88 #include <sys/timeb.h>
  89 #include <objidl.h>
  90 #include <shlobj.h>
  91 
  92 #include <malloc.h>
  93 #include <signal.h>
  94 #include <direct.h>
  95 #include <errno.h>
  96 #include <fcntl.h>
  97 #include <io.h>
  98 #include <process.h>              // For _beginthreadex(), _endthreadex()
  99 #include <imagehlp.h>             // For os::dll_address_to_function_name
 100 // for enumerating dll libraries
 101 #include <vdmdbg.h>
 102 #include <psapi.h>
 103 #include <mmsystem.h>
 104 #include <winsock2.h>
 105 
 106 // for timer info max values which include all bits
 107 #define ALL_64_BITS CONST64(-1)
 108 
 109 // For DLL loading/load error detection
 110 // Values of PE COFF
 111 #define IMAGE_FILE_PTR_TO_SIGNATURE 0x3c
 112 #define IMAGE_FILE_SIGNATURE_LENGTH 4
 113 
 114 static HANDLE main_process;
 115 static HANDLE main_thread;
 116 static int    main_thread_id;
 117 
 118 static FILETIME process_creation_time;
 119 static FILETIME process_exit_time;
 120 static FILETIME process_user_time;
 121 static FILETIME process_kernel_time;
 122 
 123 #ifdef _M_AMD64
 124   #define __CPU__ amd64
 125 #else
 126   #define __CPU__ i486
 127 #endif
 128 
 129 #if INCLUDE_AOT
 130 PVOID  topLevelVectoredExceptionHandler = NULL;
 131 LONG WINAPI topLevelVectoredExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo);
 132 #endif
 133 
 134 // save DLL module handle, used by GetModuleFileName
 135 
 136 HINSTANCE vm_lib_handle;
 137 
 138 BOOL WINAPI DllMain(HINSTANCE hinst, DWORD reason, LPVOID reserved) {
 139   switch (reason) {
 140   case DLL_PROCESS_ATTACH:
 141     vm_lib_handle = hinst;
 142     if (ForceTimeHighResolution) {
 143       timeBeginPeriod(1L);
 144     }
 145     WindowsDbgHelp::pre_initialize();
 146     SymbolEngine::pre_initialize();
 147     break;
 148   case DLL_PROCESS_DETACH:
 149     if (ForceTimeHighResolution) {
 150       timeEndPeriod(1L);
 151     }
 152 #if INCLUDE_AOT
 153     if (topLevelVectoredExceptionHandler != NULL) {
 154       RemoveVectoredExceptionHandler(topLevelVectoredExceptionHandler);
 155       topLevelVectoredExceptionHandler = NULL;
 156     }
 157 #endif
 158     break;
 159   default:
 160     break;
 161   }
 162   return true;
 163 }
 164 
 165 static inline double fileTimeAsDouble(FILETIME* time) {
 166   const double high  = (double) ((unsigned int) ~0);
 167   const double split = 10000000.0;
 168   double result = (time->dwLowDateTime / split) +
 169                    time->dwHighDateTime * (high/split);
 170   return result;
 171 }
 172 
 173 // Implementation of os
 174 
 175 bool os::unsetenv(const char* name) {
 176   assert(name != NULL, "Null pointer");
 177   return (SetEnvironmentVariable(name, NULL) == TRUE);
 178 }
 179 
 180 // No setuid programs under Windows.
 181 bool os::have_special_privileges() {
 182   return false;
 183 }
 184 
 185 
 186 // This method is  a periodic task to check for misbehaving JNI applications
 187 // under CheckJNI, we can add any periodic checks here.
 188 // For Windows at the moment does nothing
 189 void os::run_periodic_checks() {
 190   return;
 191 }
 192 
 193 // previous UnhandledExceptionFilter, if there is one
 194 static LPTOP_LEVEL_EXCEPTION_FILTER prev_uef_handler = NULL;
 195 
 196 LONG WINAPI Handle_FLT_Exception(struct _EXCEPTION_POINTERS* exceptionInfo);
 197 
 198 void os::init_system_properties_values() {
 199   // sysclasspath, java_home, dll_dir
 200   {
 201     char *home_path;
 202     char *dll_path;
 203     char *pslash;
 204     const char *bin = "\\bin";
 205     char home_dir[MAX_PATH + 1];
 206     char *alt_home_dir = ::getenv("_ALT_JAVA_HOME_DIR");
 207 
 208     if (alt_home_dir != NULL)  {
 209       strncpy(home_dir, alt_home_dir, MAX_PATH + 1);
 210       home_dir[MAX_PATH] = '\0';
 211     } else {
 212       os::jvm_path(home_dir, sizeof(home_dir));
 213       // Found the full path to jvm.dll.
 214       // Now cut the path to <java_home>/jre if we can.
 215       *(strrchr(home_dir, '\\')) = '\0';  // get rid of \jvm.dll
 216       pslash = strrchr(home_dir, '\\');
 217       if (pslash != NULL) {
 218         *pslash = '\0';                   // get rid of \{client|server}
 219         pslash = strrchr(home_dir, '\\');
 220         if (pslash != NULL) {
 221           *pslash = '\0';                 // get rid of \bin
 222         }
 223       }
 224     }
 225 
 226     home_path = NEW_C_HEAP_ARRAY(char, strlen(home_dir) + 1, mtInternal);
 227     strcpy(home_path, home_dir);
 228     Arguments::set_java_home(home_path);
 229     FREE_C_HEAP_ARRAY(char, home_path);
 230 
 231     dll_path = NEW_C_HEAP_ARRAY(char, strlen(home_dir) + strlen(bin) + 1,
 232                                 mtInternal);
 233     strcpy(dll_path, home_dir);
 234     strcat(dll_path, bin);
 235     Arguments::set_dll_dir(dll_path);
 236     FREE_C_HEAP_ARRAY(char, dll_path);
 237 
 238     if (!set_boot_path('\\', ';')) {
 239       vm_exit_during_initialization("Failed setting boot class path.", NULL);
 240     }
 241   }
 242 
 243 // library_path
 244 #define EXT_DIR "\\lib\\ext"
 245 #define BIN_DIR "\\bin"
 246 #define PACKAGE_DIR "\\Sun\\Java"
 247   {
 248     // Win32 library search order (See the documentation for LoadLibrary):
 249     //
 250     // 1. The directory from which application is loaded.
 251     // 2. The system wide Java Extensions directory (Java only)
 252     // 3. System directory (GetSystemDirectory)
 253     // 4. Windows directory (GetWindowsDirectory)
 254     // 5. The PATH environment variable
 255     // 6. The current directory
 256 
 257     char *library_path;
 258     char tmp[MAX_PATH];
 259     char *path_str = ::getenv("PATH");
 260 
 261     library_path = NEW_C_HEAP_ARRAY(char, MAX_PATH * 5 + sizeof(PACKAGE_DIR) +
 262                                     sizeof(BIN_DIR) + (path_str ? strlen(path_str) : 0) + 10, mtInternal);
 263 
 264     library_path[0] = '\0';
 265 
 266     GetModuleFileName(NULL, tmp, sizeof(tmp));
 267     *(strrchr(tmp, '\\')) = '\0';
 268     strcat(library_path, tmp);
 269 
 270     GetWindowsDirectory(tmp, sizeof(tmp));
 271     strcat(library_path, ";");
 272     strcat(library_path, tmp);
 273     strcat(library_path, PACKAGE_DIR BIN_DIR);
 274 
 275     GetSystemDirectory(tmp, sizeof(tmp));
 276     strcat(library_path, ";");
 277     strcat(library_path, tmp);
 278 
 279     GetWindowsDirectory(tmp, sizeof(tmp));
 280     strcat(library_path, ";");
 281     strcat(library_path, tmp);
 282 
 283     if (path_str) {
 284       strcat(library_path, ";");
 285       strcat(library_path, path_str);
 286     }
 287 
 288     strcat(library_path, ";.");
 289 
 290     Arguments::set_library_path(library_path);
 291     FREE_C_HEAP_ARRAY(char, library_path);
 292   }
 293 
 294   // Default extensions directory
 295   {
 296     char path[MAX_PATH];
 297     char buf[2 * MAX_PATH + 2 * sizeof(EXT_DIR) + sizeof(PACKAGE_DIR) + 1];
 298     GetWindowsDirectory(path, MAX_PATH);
 299     sprintf(buf, "%s%s;%s%s%s", Arguments::get_java_home(), EXT_DIR,
 300             path, PACKAGE_DIR, EXT_DIR);
 301     Arguments::set_ext_dirs(buf);
 302   }
 303   #undef EXT_DIR
 304   #undef BIN_DIR
 305   #undef PACKAGE_DIR
 306 
 307 #ifndef _WIN64
 308   // set our UnhandledExceptionFilter and save any previous one
 309   prev_uef_handler = SetUnhandledExceptionFilter(Handle_FLT_Exception);
 310 #endif
 311 
 312   // Done
 313   return;
 314 }
 315 
 316 void os::breakpoint() {
 317   DebugBreak();
 318 }
 319 
 320 // Invoked from the BREAKPOINT Macro
 321 extern "C" void breakpoint() {
 322   os::breakpoint();
 323 }
 324 
 325 // RtlCaptureStackBackTrace Windows API may not exist prior to Windows XP.
 326 // So far, this method is only used by Native Memory Tracking, which is
 327 // only supported on Windows XP or later.
 328 //
 329 int os::get_native_stack(address* stack, int frames, int toSkip) {
 330   int captured = RtlCaptureStackBackTrace(toSkip + 1, frames, (PVOID*)stack, NULL);
 331   for (int index = captured; index < frames; index ++) {
 332     stack[index] = NULL;
 333   }
 334   return captured;
 335 }
 336 
 337 
 338 // os::current_stack_base()
 339 //
 340 //   Returns the base of the stack, which is the stack's
 341 //   starting address.  This function must be called
 342 //   while running on the stack of the thread being queried.
 343 
 344 address os::current_stack_base() {
 345   MEMORY_BASIC_INFORMATION minfo;
 346   address stack_bottom;
 347   size_t stack_size;
 348 
 349   VirtualQuery(&minfo, &minfo, sizeof(minfo));
 350   stack_bottom =  (address)minfo.AllocationBase;
 351   stack_size = minfo.RegionSize;
 352 
 353   // Add up the sizes of all the regions with the same
 354   // AllocationBase.
 355   while (1) {
 356     VirtualQuery(stack_bottom+stack_size, &minfo, sizeof(minfo));
 357     if (stack_bottom == (address)minfo.AllocationBase) {
 358       stack_size += minfo.RegionSize;
 359     } else {
 360       break;
 361     }
 362   }
 363   return stack_bottom + stack_size;
 364 }
 365 
 366 size_t os::current_stack_size() {
 367   size_t sz;
 368   MEMORY_BASIC_INFORMATION minfo;
 369   VirtualQuery(&minfo, &minfo, sizeof(minfo));
 370   sz = (size_t)os::current_stack_base() - (size_t)minfo.AllocationBase;
 371   return sz;
 372 }
 373 
 374 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) {
 375   MEMORY_BASIC_INFORMATION minfo;
 376   committed_start = NULL;
 377   committed_size = 0;
 378   address top = start + size;
 379   const address start_addr = start;
 380   while (start < top) {
 381     VirtualQuery(start, &minfo, sizeof(minfo));
 382     if ((minfo.State & MEM_COMMIT) == 0) {  // not committed
 383       if (committed_start != NULL) {
 384         break;
 385       }
 386     } else {  // committed
 387       if (committed_start == NULL) {
 388         committed_start = start;
 389       }
 390       size_t offset = start - (address)minfo.BaseAddress;
 391       committed_size += minfo.RegionSize - offset;
 392     }
 393     start = (address)minfo.BaseAddress + minfo.RegionSize;
 394   }
 395 
 396   if (committed_start == NULL) {
 397     assert(committed_size == 0, "Sanity");
 398     return false;
 399   } else {
 400     assert(committed_start >= start_addr && committed_start < top, "Out of range");
 401     // current region may go beyond the limit, trim to the limit
 402     committed_size = MIN2(committed_size, size_t(top - committed_start));
 403     return true;
 404   }
 405 }
 406 
 407 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
 408   const struct tm* time_struct_ptr = localtime(clock);
 409   if (time_struct_ptr != NULL) {
 410     *res = *time_struct_ptr;
 411     return res;
 412   }
 413   return NULL;
 414 }
 415 
 416 struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
 417   const struct tm* time_struct_ptr = gmtime(clock);
 418   if (time_struct_ptr != NULL) {
 419     *res = *time_struct_ptr;
 420     return res;
 421   }
 422   return NULL;
 423 }
 424 
 425 LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo);
 426 
 427 // Thread start routine for all newly created threads
 428 static unsigned __stdcall thread_native_entry(Thread* thread) {
 429 
 430   thread->record_stack_base_and_size();
 431 
 432   // Try to randomize the cache line index of hot stack frames.
 433   // This helps when threads of the same stack traces evict each other's
 434   // cache lines. The threads can be either from the same JVM instance, or
 435   // from different JVM instances. The benefit is especially true for
 436   // processors with hyperthreading technology.
 437   static int counter = 0;
 438   int pid = os::current_process_id();
 439   _alloca(((pid ^ counter++) & 7) * 128);
 440 
 441   thread->initialize_thread_current();
 442 
 443   OSThread* osthr = thread->osthread();
 444   assert(osthr->get_state() == RUNNABLE, "invalid os thread state");
 445 
 446   if (UseNUMA) {
 447     int lgrp_id = os::numa_get_group_id();
 448     if (lgrp_id != -1) {
 449       thread->set_lgrp_id(lgrp_id);
 450     }
 451   }
 452 
 453   // Diagnostic code to investigate JDK-6573254
 454   int res = 30115;  // non-java thread
 455   if (thread->is_Java_thread()) {
 456     res = 20115;    // java thread
 457   }
 458 
 459   log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ").", os::current_thread_id());
 460 
 461   // Install a win32 structured exception handler around every thread created
 462   // by VM, so VM can generate error dump when an exception occurred in non-
 463   // Java thread (e.g. VM thread).
 464   __try {
 465     thread->call_run();
 466   } __except(topLevelExceptionFilter(
 467                                      (_EXCEPTION_POINTERS*)_exception_info())) {
 468     // Nothing to do.
 469   }
 470 
 471   // Note: at this point the thread object may already have deleted itself.
 472   // Do not dereference it from here on out.
 473 
 474   log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ").", os::current_thread_id());
 475 
 476   // One less thread is executing
 477   // When the VMThread gets here, the main thread may have already exited
 478   // which frees the CodeHeap containing the Atomic::add code
 479   if (thread != VMThread::vm_thread() && VMThread::vm_thread() != NULL) {
 480     Atomic::dec(&os::win32::_os_thread_count);
 481   }
 482 
 483   // Thread must not return from exit_process_or_thread(), but if it does,
 484   // let it proceed to exit normally
 485   return (unsigned)os::win32::exit_process_or_thread(os::win32::EPT_THREAD, res);
 486 }
 487 
 488 static OSThread* create_os_thread(Thread* thread, HANDLE thread_handle,
 489                                   int thread_id) {
 490   // Allocate the OSThread object
 491   OSThread* osthread = new OSThread(NULL, NULL);
 492   if (osthread == NULL) return NULL;
 493 
 494   // Initialize the JDK library's interrupt event.
 495   // This should really be done when OSThread is constructed,
 496   // but there is no way for a constructor to report failure to
 497   // allocate the event.
 498   HANDLE interrupt_event = CreateEvent(NULL, true, false, NULL);
 499   if (interrupt_event == NULL) {
 500     delete osthread;
 501     return NULL;
 502   }
 503   osthread->set_interrupt_event(interrupt_event);
 504 
 505   // Store info on the Win32 thread into the OSThread
 506   osthread->set_thread_handle(thread_handle);
 507   osthread->set_thread_id(thread_id);
 508 
 509   if (UseNUMA) {
 510     int lgrp_id = os::numa_get_group_id();
 511     if (lgrp_id != -1) {
 512       thread->set_lgrp_id(lgrp_id);
 513     }
 514   }
 515 
 516   // Initial thread state is INITIALIZED, not SUSPENDED
 517   osthread->set_state(INITIALIZED);
 518 
 519   return osthread;
 520 }
 521 
 522 
 523 bool os::create_attached_thread(JavaThread* thread) {
 524 #ifdef ASSERT
 525   thread->verify_not_published();
 526 #endif
 527   HANDLE thread_h;
 528   if (!DuplicateHandle(main_process, GetCurrentThread(), GetCurrentProcess(),
 529                        &thread_h, THREAD_ALL_ACCESS, false, 0)) {
 530     fatal("DuplicateHandle failed\n");
 531   }
 532   OSThread* osthread = create_os_thread(thread, thread_h,
 533                                         (int)current_thread_id());
 534   if (osthread == NULL) {
 535     return false;
 536   }
 537 
 538   // Initial thread state is RUNNABLE
 539   osthread->set_state(RUNNABLE);
 540 
 541   thread->set_osthread(osthread);
 542 
 543   log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ").",
 544     os::current_thread_id());
 545 
 546   return true;
 547 }
 548 
 549 bool os::create_main_thread(JavaThread* thread) {
 550 #ifdef ASSERT
 551   thread->verify_not_published();
 552 #endif
 553   if (_starting_thread == NULL) {
 554     _starting_thread = create_os_thread(thread, main_thread, main_thread_id);
 555     if (_starting_thread == NULL) {
 556       return false;
 557     }
 558   }
 559 
 560   // The primordial thread is runnable from the start)
 561   _starting_thread->set_state(RUNNABLE);
 562 
 563   thread->set_osthread(_starting_thread);
 564   return true;
 565 }
 566 
 567 // Helper function to trace _beginthreadex attributes,
 568 //  similar to os::Posix::describe_pthread_attr()
 569 static char* describe_beginthreadex_attributes(char* buf, size_t buflen,
 570                                                size_t stacksize, unsigned initflag) {
 571   stringStream ss(buf, buflen);
 572   if (stacksize == 0) {
 573     ss.print("stacksize: default, ");
 574   } else {
 575     ss.print("stacksize: " SIZE_FORMAT "k, ", stacksize / 1024);
 576   }
 577   ss.print("flags: ");
 578   #define PRINT_FLAG(f) if (initflag & f) ss.print( #f " ");
 579   #define ALL(X) \
 580     X(CREATE_SUSPENDED) \
 581     X(STACK_SIZE_PARAM_IS_A_RESERVATION)
 582   ALL(PRINT_FLAG)
 583   #undef ALL
 584   #undef PRINT_FLAG
 585   return buf;
 586 }
 587 
 588 // Allocate and initialize a new OSThread
 589 bool os::create_thread(Thread* thread, ThreadType thr_type,
 590                        size_t stack_size) {
 591   unsigned thread_id;
 592 
 593   // Allocate the OSThread object
 594   OSThread* osthread = new OSThread(NULL, NULL);
 595   if (osthread == NULL) {
 596     return false;
 597   }
 598 
 599   // Initialize the JDK library's interrupt event.
 600   // This should really be done when OSThread is constructed,
 601   // but there is no way for a constructor to report failure to
 602   // allocate the event.
 603   HANDLE interrupt_event = CreateEvent(NULL, true, false, NULL);
 604   if (interrupt_event == NULL) {
 605     delete osthread;
 606     return false;
 607   }
 608   osthread->set_interrupt_event(interrupt_event);
 609   // We don't call set_interrupted(false) as it will trip the assert in there
 610   // as we are not operating on the current thread. We don't need to call it
 611   // because the initial state is already correct.
 612 
 613   thread->set_osthread(osthread);
 614 
 615   if (stack_size == 0) {
 616     switch (thr_type) {
 617     case os::java_thread:
 618       // Java threads use ThreadStackSize which default value can be changed with the flag -Xss
 619       if (JavaThread::stack_size_at_create() > 0) {
 620         stack_size = JavaThread::stack_size_at_create();
 621       }
 622       break;
 623     case os::compiler_thread:
 624       if (CompilerThreadStackSize > 0) {
 625         stack_size = (size_t)(CompilerThreadStackSize * K);
 626         break;
 627       } // else fall through:
 628         // use VMThreadStackSize if CompilerThreadStackSize is not defined
 629     case os::vm_thread:
 630     case os::pgc_thread:
 631     case os::cgc_thread:
 632     case os::watcher_thread:
 633       if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
 634       break;
 635     }
 636   }
 637 
 638   // Create the Win32 thread
 639   //
 640   // Contrary to what MSDN document says, "stack_size" in _beginthreadex()
 641   // does not specify stack size. Instead, it specifies the size of
 642   // initially committed space. The stack size is determined by
 643   // PE header in the executable. If the committed "stack_size" is larger
 644   // than default value in the PE header, the stack is rounded up to the
 645   // nearest multiple of 1MB. For example if the launcher has default
 646   // stack size of 320k, specifying any size less than 320k does not
 647   // affect the actual stack size at all, it only affects the initial
 648   // commitment. On the other hand, specifying 'stack_size' larger than
 649   // default value may cause significant increase in memory usage, because
 650   // not only the stack space will be rounded up to MB, but also the
 651   // entire space is committed upfront.
 652   //
 653   // Finally Windows XP added a new flag 'STACK_SIZE_PARAM_IS_A_RESERVATION'
 654   // for CreateThread() that can treat 'stack_size' as stack size. However we
 655   // are not supposed to call CreateThread() directly according to MSDN
 656   // document because JVM uses C runtime library. The good news is that the
 657   // flag appears to work with _beginthredex() as well.
 658 
 659   const unsigned initflag = CREATE_SUSPENDED | STACK_SIZE_PARAM_IS_A_RESERVATION;
 660   HANDLE thread_handle =
 661     (HANDLE)_beginthreadex(NULL,
 662                            (unsigned)stack_size,
 663                            (unsigned (__stdcall *)(void*)) thread_native_entry,
 664                            thread,
 665                            initflag,
 666                            &thread_id);
 667 
 668   char buf[64];
 669   if (thread_handle != NULL) {
 670     log_info(os, thread)("Thread started (tid: %u, attributes: %s)",
 671       thread_id, describe_beginthreadex_attributes(buf, sizeof(buf), stack_size, initflag));
 672   } else {
 673     log_warning(os, thread)("Failed to start thread - _beginthreadex failed (%s) for attributes: %s.",
 674       os::errno_name(errno), describe_beginthreadex_attributes(buf, sizeof(buf), stack_size, initflag));
 675     // Log some OS information which might explain why creating the thread failed.
 676     log_info(os, thread)("Number of threads approx. running in the VM: %d", Threads::number_of_threads());
 677     LogStream st(Log(os, thread)::info());
 678     os::print_memory_info(&st);
 679   }
 680 
 681   if (thread_handle == NULL) {
 682     // Need to clean up stuff we've allocated so far
 683     thread->set_osthread(NULL);
 684     delete osthread;
 685     return false;
 686   }
 687 
 688   Atomic::inc(&os::win32::_os_thread_count);
 689 
 690   // Store info on the Win32 thread into the OSThread
 691   osthread->set_thread_handle(thread_handle);
 692   osthread->set_thread_id(thread_id);
 693 
 694   // Initial thread state is INITIALIZED, not SUSPENDED
 695   osthread->set_state(INITIALIZED);
 696 
 697   // The thread is returned suspended (in state INITIALIZED), and is started higher up in the call chain
 698   return true;
 699 }
 700 
 701 
 702 // Free Win32 resources related to the OSThread
 703 void os::free_thread(OSThread* osthread) {
 704   assert(osthread != NULL, "osthread not set");
 705 
 706   // We are told to free resources of the argument thread,
 707   // but we can only really operate on the current thread.
 708   assert(Thread::current()->osthread() == osthread,
 709          "os::free_thread but not current thread");
 710 
 711   CloseHandle(osthread->thread_handle());
 712   delete osthread;
 713 }
 714 
 715 static jlong first_filetime;
 716 static jlong initial_performance_count;
 717 static jlong performance_frequency;
 718 
 719 
 720 jlong as_long(LARGE_INTEGER x) {
 721   jlong result = 0; // initialization to avoid warning
 722   set_high(&result, x.HighPart);
 723   set_low(&result, x.LowPart);
 724   return result;
 725 }
 726 
 727 
 728 jlong os::elapsed_counter() {
 729   LARGE_INTEGER count;
 730   QueryPerformanceCounter(&count);
 731   return as_long(count) - initial_performance_count;
 732 }
 733 
 734 
 735 jlong os::elapsed_frequency() {
 736   return performance_frequency;
 737 }
 738 
 739 
 740 julong os::available_memory() {
 741   return win32::available_memory();
 742 }
 743 
 744 julong os::win32::available_memory() {
 745   // Use GlobalMemoryStatusEx() because GlobalMemoryStatus() may return incorrect
 746   // value if total memory is larger than 4GB
 747   MEMORYSTATUSEX ms;
 748   ms.dwLength = sizeof(ms);
 749   GlobalMemoryStatusEx(&ms);
 750 
 751   return (julong)ms.ullAvailPhys;
 752 }
 753 
 754 julong os::physical_memory() {
 755   return win32::physical_memory();
 756 }
 757 
 758 bool os::has_allocatable_memory_limit(julong* limit) {
 759   MEMORYSTATUSEX ms;
 760   ms.dwLength = sizeof(ms);
 761   GlobalMemoryStatusEx(&ms);
 762 #ifdef _LP64
 763   *limit = (julong)ms.ullAvailVirtual;
 764   return true;
 765 #else
 766   // Limit to 1400m because of the 2gb address space wall
 767   *limit = MIN2((julong)1400*M, (julong)ms.ullAvailVirtual);
 768   return true;
 769 #endif
 770 }
 771 
 772 int os::active_processor_count() {
 773   // User has overridden the number of active processors
 774   if (ActiveProcessorCount > 0) {
 775     log_trace(os)("active_processor_count: "
 776                   "active processor count set by user : %d",
 777                   ActiveProcessorCount);
 778     return ActiveProcessorCount;
 779   }
 780 
 781   DWORD_PTR lpProcessAffinityMask = 0;
 782   DWORD_PTR lpSystemAffinityMask = 0;
 783   int proc_count = processor_count();
 784   if (proc_count <= sizeof(UINT_PTR) * BitsPerByte &&
 785       GetProcessAffinityMask(GetCurrentProcess(), &lpProcessAffinityMask, &lpSystemAffinityMask)) {
 786     // Nof active processors is number of bits in process affinity mask
 787     int bitcount = 0;
 788     while (lpProcessAffinityMask != 0) {
 789       lpProcessAffinityMask = lpProcessAffinityMask & (lpProcessAffinityMask-1);
 790       bitcount++;
 791     }
 792     return bitcount;
 793   } else {
 794     return proc_count;
 795   }
 796 }
 797 
 798 void os::set_native_thread_name(const char *name) {
 799 
 800   // See: http://msdn.microsoft.com/en-us/library/xcb2z8hs.aspx
 801   //
 802   // Note that unfortunately this only works if the process
 803   // is already attached to a debugger; debugger must observe
 804   // the exception below to show the correct name.
 805 
 806   // If there is no debugger attached skip raising the exception
 807   if (!IsDebuggerPresent()) {
 808     return;
 809   }
 810 
 811   const DWORD MS_VC_EXCEPTION = 0x406D1388;
 812   struct {
 813     DWORD dwType;     // must be 0x1000
 814     LPCSTR szName;    // pointer to name (in user addr space)
 815     DWORD dwThreadID; // thread ID (-1=caller thread)
 816     DWORD dwFlags;    // reserved for future use, must be zero
 817   } info;
 818 
 819   info.dwType = 0x1000;
 820   info.szName = name;
 821   info.dwThreadID = -1;
 822   info.dwFlags = 0;
 823 
 824   __try {
 825     RaiseException (MS_VC_EXCEPTION, 0, sizeof(info)/sizeof(DWORD), (const ULONG_PTR*)&info );
 826   } __except(EXCEPTION_EXECUTE_HANDLER) {}
 827 }
 828 
 829 bool os::distribute_processes(uint length, uint* distribution) {
 830   // Not yet implemented.
 831   return false;
 832 }
 833 
 834 bool os::bind_to_processor(uint processor_id) {
 835   // Not yet implemented.
 836   return false;
 837 }
 838 
 839 void os::win32::initialize_performance_counter() {
 840   LARGE_INTEGER count;
 841   QueryPerformanceFrequency(&count);
 842   performance_frequency = as_long(count);
 843   QueryPerformanceCounter(&count);
 844   initial_performance_count = as_long(count);
 845 }
 846 
 847 
 848 double os::elapsedTime() {
 849   return (double) elapsed_counter() / (double) elapsed_frequency();
 850 }
 851 
 852 
 853 // Windows format:
 854 //   The FILETIME structure is a 64-bit value representing the number of 100-nanosecond intervals since January 1, 1601.
 855 // Java format:
 856 //   Java standards require the number of milliseconds since 1/1/1970
 857 
 858 // Constant offset - calculated using offset()
 859 static jlong  _offset   = 116444736000000000;
 860 // Fake time counter for reproducible results when debugging
 861 static jlong  fake_time = 0;
 862 
 863 #ifdef ASSERT
 864 // Just to be safe, recalculate the offset in debug mode
 865 static jlong _calculated_offset = 0;
 866 static int   _has_calculated_offset = 0;
 867 
 868 jlong offset() {
 869   if (_has_calculated_offset) return _calculated_offset;
 870   SYSTEMTIME java_origin;
 871   java_origin.wYear          = 1970;
 872   java_origin.wMonth         = 1;
 873   java_origin.wDayOfWeek     = 0; // ignored
 874   java_origin.wDay           = 1;
 875   java_origin.wHour          = 0;
 876   java_origin.wMinute        = 0;
 877   java_origin.wSecond        = 0;
 878   java_origin.wMilliseconds  = 0;
 879   FILETIME jot;
 880   if (!SystemTimeToFileTime(&java_origin, &jot)) {
 881     fatal("Error = %d\nWindows error", GetLastError());
 882   }
 883   _calculated_offset = jlong_from(jot.dwHighDateTime, jot.dwLowDateTime);
 884   _has_calculated_offset = 1;
 885   assert(_calculated_offset == _offset, "Calculated and constant time offsets must be equal");
 886   return _calculated_offset;
 887 }
 888 #else
 889 jlong offset() {
 890   return _offset;
 891 }
 892 #endif
 893 
 894 jlong windows_to_java_time(FILETIME wt) {
 895   jlong a = jlong_from(wt.dwHighDateTime, wt.dwLowDateTime);
 896   return (a - offset()) / 10000;
 897 }
 898 
 899 // Returns time ticks in (10th of micro seconds)
 900 jlong windows_to_time_ticks(FILETIME wt) {
 901   jlong a = jlong_from(wt.dwHighDateTime, wt.dwLowDateTime);
 902   return (a - offset());
 903 }
 904 
 905 FILETIME java_to_windows_time(jlong l) {
 906   jlong a = (l * 10000) + offset();
 907   FILETIME result;
 908   result.dwHighDateTime = high(a);
 909   result.dwLowDateTime  = low(a);
 910   return result;
 911 }
 912 
 913 bool os::supports_vtime() { return true; }
 914 bool os::enable_vtime() { return false; }
 915 bool os::vtime_enabled() { return false; }
 916 
 917 double os::elapsedVTime() {
 918   FILETIME created;
 919   FILETIME exited;
 920   FILETIME kernel;
 921   FILETIME user;
 922   if (GetThreadTimes(GetCurrentThread(), &created, &exited, &kernel, &user) != 0) {
 923     // the resolution of windows_to_java_time() should be sufficient (ms)
 924     return (double) (windows_to_java_time(kernel) + windows_to_java_time(user)) / MILLIUNITS;
 925   } else {
 926     return elapsedTime();
 927   }
 928 }
 929 
 930 jlong os::javaTimeMillis() {
 931   FILETIME wt;
 932   GetSystemTimeAsFileTime(&wt);
 933   return windows_to_java_time(wt);
 934 }
 935 
 936 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
 937   FILETIME wt;
 938   GetSystemTimeAsFileTime(&wt);
 939   jlong ticks = windows_to_time_ticks(wt); // 10th of micros
 940   jlong secs = jlong(ticks / 10000000); // 10000 * 1000
 941   seconds = secs;
 942   nanos = jlong(ticks - (secs*10000000)) * 100;
 943 }
 944 
 945 jlong os::javaTimeNanos() {
 946     LARGE_INTEGER current_count;
 947     QueryPerformanceCounter(&current_count);
 948     double current = as_long(current_count);
 949     double freq = performance_frequency;
 950     jlong time = (jlong)((current/freq) * NANOSECS_PER_SEC);
 951     return time;
 952 }
 953 
 954 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
 955   jlong freq = performance_frequency;
 956   if (freq < NANOSECS_PER_SEC) {
 957     // the performance counter is 64 bits and we will
 958     // be multiplying it -- so no wrap in 64 bits
 959     info_ptr->max_value = ALL_64_BITS;
 960   } else if (freq > NANOSECS_PER_SEC) {
 961     // use the max value the counter can reach to
 962     // determine the max value which could be returned
 963     julong max_counter = (julong)ALL_64_BITS;
 964     info_ptr->max_value = (jlong)(max_counter / (freq / NANOSECS_PER_SEC));
 965   } else {
 966     // the performance counter is 64 bits and we will
 967     // be using it directly -- so no wrap in 64 bits
 968     info_ptr->max_value = ALL_64_BITS;
 969   }
 970 
 971   // using a counter, so no skipping
 972   info_ptr->may_skip_backward = false;
 973   info_ptr->may_skip_forward = false;
 974 
 975   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
 976 }
 977 
 978 char* os::local_time_string(char *buf, size_t buflen) {
 979   SYSTEMTIME st;
 980   GetLocalTime(&st);
 981   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
 982                st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond);
 983   return buf;
 984 }
 985 
 986 bool os::getTimesSecs(double* process_real_time,
 987                       double* process_user_time,
 988                       double* process_system_time) {
 989   HANDLE h_process = GetCurrentProcess();
 990   FILETIME create_time, exit_time, kernel_time, user_time;
 991   BOOL result = GetProcessTimes(h_process,
 992                                 &create_time,
 993                                 &exit_time,
 994                                 &kernel_time,
 995                                 &user_time);
 996   if (result != 0) {
 997     FILETIME wt;
 998     GetSystemTimeAsFileTime(&wt);
 999     jlong rtc_millis = windows_to_java_time(wt);
1000     *process_real_time = ((double) rtc_millis) / ((double) MILLIUNITS);
1001     *process_user_time =
1002       (double) jlong_from(user_time.dwHighDateTime, user_time.dwLowDateTime) / (10 * MICROUNITS);
1003     *process_system_time =
1004       (double) jlong_from(kernel_time.dwHighDateTime, kernel_time.dwLowDateTime) / (10 * MICROUNITS);
1005     return true;
1006   } else {
1007     return false;
1008   }
1009 }
1010 
1011 void os::shutdown() {
1012   // allow PerfMemory to attempt cleanup of any persistent resources
1013   perfMemory_exit();
1014 
1015   // flush buffered output, finish log files
1016   ostream_abort();
1017 
1018   // Check for abort hook
1019   abort_hook_t abort_hook = Arguments::abort_hook();
1020   if (abort_hook != NULL) {
1021     abort_hook();
1022   }
1023 }
1024 
1025 
1026 static HANDLE dumpFile = NULL;
1027 
1028 // Check if dump file can be created.
1029 void os::check_dump_limit(char* buffer, size_t buffsz) {
1030   bool status = true;
1031   if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
1032     jio_snprintf(buffer, buffsz, "CreateCoredumpOnCrash is disabled from command line");
1033     status = false;
1034   }
1035 
1036 #ifndef ASSERT
1037   if (!os::win32::is_windows_server() && FLAG_IS_DEFAULT(CreateCoredumpOnCrash)) {
1038     jio_snprintf(buffer, buffsz, "Minidumps are not enabled by default on client versions of Windows");
1039     status = false;
1040   }
1041 #endif
1042 
1043   if (status) {
1044     const char* cwd = get_current_directory(NULL, 0);
1045     int pid = current_process_id();
1046     if (cwd != NULL) {
1047       jio_snprintf(buffer, buffsz, "%s\\hs_err_pid%u.mdmp", cwd, pid);
1048     } else {
1049       jio_snprintf(buffer, buffsz, ".\\hs_err_pid%u.mdmp", pid);
1050     }
1051 
1052     if (dumpFile == NULL &&
1053        (dumpFile = CreateFile(buffer, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL))
1054                  == INVALID_HANDLE_VALUE) {
1055       jio_snprintf(buffer, buffsz, "Failed to create minidump file (0x%x).", GetLastError());
1056       status = false;
1057     }
1058   }
1059   VMError::record_coredump_status(buffer, status);
1060 }
1061 
1062 void os::abort(bool dump_core, void* siginfo, const void* context) {
1063   EXCEPTION_POINTERS ep;
1064   MINIDUMP_EXCEPTION_INFORMATION mei;
1065   MINIDUMP_EXCEPTION_INFORMATION* pmei;
1066 
1067   HANDLE hProcess = GetCurrentProcess();
1068   DWORD processId = GetCurrentProcessId();
1069   MINIDUMP_TYPE dumpType;
1070 
1071   shutdown();
1072   if (!dump_core || dumpFile == NULL) {
1073     if (dumpFile != NULL) {
1074       CloseHandle(dumpFile);
1075     }
1076     win32::exit_process_or_thread(win32::EPT_PROCESS, 1);
1077   }
1078 
1079   dumpType = (MINIDUMP_TYPE)(MiniDumpWithFullMemory | MiniDumpWithHandleData |
1080     MiniDumpWithFullMemoryInfo | MiniDumpWithThreadInfo | MiniDumpWithUnloadedModules);
1081 
1082   if (siginfo != NULL && context != NULL) {
1083     ep.ContextRecord = (PCONTEXT) context;
1084     ep.ExceptionRecord = (PEXCEPTION_RECORD) siginfo;
1085 
1086     mei.ThreadId = GetCurrentThreadId();
1087     mei.ExceptionPointers = &ep;
1088     pmei = &mei;
1089   } else {
1090     pmei = NULL;
1091   }
1092 
1093   // Older versions of dbghelp.dll (the one shipped with Win2003 for example) may not support all
1094   // the dump types we really want. If first call fails, lets fall back to just use MiniDumpWithFullMemory then.
1095   if (!WindowsDbgHelp::miniDumpWriteDump(hProcess, processId, dumpFile, dumpType, pmei, NULL, NULL) &&
1096       !WindowsDbgHelp::miniDumpWriteDump(hProcess, processId, dumpFile, (MINIDUMP_TYPE)MiniDumpWithFullMemory, pmei, NULL, NULL)) {
1097     jio_fprintf(stderr, "Call to MiniDumpWriteDump() failed (Error 0x%x)\n", GetLastError());
1098   }
1099   CloseHandle(dumpFile);
1100   win32::exit_process_or_thread(win32::EPT_PROCESS, 1);
1101 }
1102 
1103 // Die immediately, no exit hook, no abort hook, no cleanup.
1104 void os::die() {
1105   win32::exit_process_or_thread(win32::EPT_PROCESS_DIE, -1);
1106 }
1107 
1108 // Directory routines copied from src/win32/native/java/io/dirent_md.c
1109 //  * dirent_md.c       1.15 00/02/02
1110 //
1111 // The declarations for DIR and struct dirent are in jvm_win32.h.
1112 
1113 // Caller must have already run dirname through JVM_NativePath, which removes
1114 // duplicate slashes and converts all instances of '/' into '\\'.
1115 
1116 DIR * os::opendir(const char *dirname) {
1117   assert(dirname != NULL, "just checking");   // hotspot change
1118   DIR *dirp = (DIR *)malloc(sizeof(DIR), mtInternal);
1119   DWORD fattr;                                // hotspot change
1120   char alt_dirname[4] = { 0, 0, 0, 0 };
1121 
1122   if (dirp == 0) {
1123     errno = ENOMEM;
1124     return 0;
1125   }
1126 
1127   // Win32 accepts "\" in its POSIX stat(), but refuses to treat it
1128   // as a directory in FindFirstFile().  We detect this case here and
1129   // prepend the current drive name.
1130   //
1131   if (dirname[1] == '\0' && dirname[0] == '\\') {
1132     alt_dirname[0] = _getdrive() + 'A' - 1;
1133     alt_dirname[1] = ':';
1134     alt_dirname[2] = '\\';
1135     alt_dirname[3] = '\0';
1136     dirname = alt_dirname;
1137   }
1138 
1139   dirp->path = (char *)malloc(strlen(dirname) + 5, mtInternal);
1140   if (dirp->path == 0) {
1141     free(dirp);
1142     errno = ENOMEM;
1143     return 0;
1144   }
1145   strcpy(dirp->path, dirname);
1146 
1147   fattr = GetFileAttributes(dirp->path);
1148   if (fattr == 0xffffffff) {
1149     free(dirp->path);
1150     free(dirp);
1151     errno = ENOENT;
1152     return 0;
1153   } else if ((fattr & FILE_ATTRIBUTE_DIRECTORY) == 0) {
1154     free(dirp->path);
1155     free(dirp);
1156     errno = ENOTDIR;
1157     return 0;
1158   }
1159 
1160   // Append "*.*", or possibly "\\*.*", to path
1161   if (dirp->path[1] == ':' &&
1162       (dirp->path[2] == '\0' ||
1163       (dirp->path[2] == '\\' && dirp->path[3] == '\0'))) {
1164     // No '\\' needed for cases like "Z:" or "Z:\"
1165     strcat(dirp->path, "*.*");
1166   } else {
1167     strcat(dirp->path, "\\*.*");
1168   }
1169 
1170   dirp->handle = FindFirstFile(dirp->path, &dirp->find_data);
1171   if (dirp->handle == INVALID_HANDLE_VALUE) {
1172     if (GetLastError() != ERROR_FILE_NOT_FOUND) {
1173       free(dirp->path);
1174       free(dirp);
1175       errno = EACCES;
1176       return 0;
1177     }
1178   }
1179   return dirp;
1180 }
1181 
1182 struct dirent * os::readdir(DIR *dirp) {
1183   assert(dirp != NULL, "just checking");      // hotspot change
1184   if (dirp->handle == INVALID_HANDLE_VALUE) {
1185     return NULL;
1186   }
1187 
1188   strcpy(dirp->dirent.d_name, dirp->find_data.cFileName);
1189 
1190   if (!FindNextFile(dirp->handle, &dirp->find_data)) {
1191     if (GetLastError() == ERROR_INVALID_HANDLE) {
1192       errno = EBADF;
1193       return NULL;
1194     }
1195     FindClose(dirp->handle);
1196     dirp->handle = INVALID_HANDLE_VALUE;
1197   }
1198 
1199   return &dirp->dirent;
1200 }
1201 
1202 int os::closedir(DIR *dirp) {
1203   assert(dirp != NULL, "just checking");      // hotspot change
1204   if (dirp->handle != INVALID_HANDLE_VALUE) {
1205     if (!FindClose(dirp->handle)) {
1206       errno = EBADF;
1207       return -1;
1208     }
1209     dirp->handle = INVALID_HANDLE_VALUE;
1210   }
1211   free(dirp->path);
1212   free(dirp);
1213   return 0;
1214 }
1215 
1216 // This must be hard coded because it's the system's temporary
1217 // directory not the java application's temp directory, ala java.io.tmpdir.
1218 const char* os::get_temp_directory() {
1219   static char path_buf[MAX_PATH];
1220   if (GetTempPath(MAX_PATH, path_buf) > 0) {
1221     return path_buf;
1222   } else {
1223     path_buf[0] = '\0';
1224     return path_buf;
1225   }
1226 }
1227 
1228 // Needs to be in os specific directory because windows requires another
1229 // header file <direct.h>
1230 const char* os::get_current_directory(char *buf, size_t buflen) {
1231   int n = static_cast<int>(buflen);
1232   if (buflen > INT_MAX)  n = INT_MAX;
1233   return _getcwd(buf, n);
1234 }
1235 
1236 //-----------------------------------------------------------
1237 // Helper functions for fatal error handler
1238 #ifdef _WIN64
1239 // Helper routine which returns true if address in
1240 // within the NTDLL address space.
1241 //
1242 static bool _addr_in_ntdll(address addr) {
1243   HMODULE hmod;
1244   MODULEINFO minfo;
1245 
1246   hmod = GetModuleHandle("NTDLL.DLL");
1247   if (hmod == NULL) return false;
1248   if (!GetModuleInformation(GetCurrentProcess(), hmod,
1249                                           &minfo, sizeof(MODULEINFO))) {
1250     return false;
1251   }
1252 
1253   if ((addr >= minfo.lpBaseOfDll) &&
1254       (addr < (address)((uintptr_t)minfo.lpBaseOfDll + (uintptr_t)minfo.SizeOfImage))) {
1255     return true;
1256   } else {
1257     return false;
1258   }
1259 }
1260 #endif
1261 
1262 struct _modinfo {
1263   address addr;
1264   char*   full_path;   // point to a char buffer
1265   int     buflen;      // size of the buffer
1266   address base_addr;
1267 };
1268 
1269 static int _locate_module_by_addr(const char * mod_fname, address base_addr,
1270                                   address top_address, void * param) {
1271   struct _modinfo *pmod = (struct _modinfo *)param;
1272   if (!pmod) return -1;
1273 
1274   if (base_addr   <= pmod->addr &&
1275       top_address > pmod->addr) {
1276     // if a buffer is provided, copy path name to the buffer
1277     if (pmod->full_path) {
1278       jio_snprintf(pmod->full_path, pmod->buflen, "%s", mod_fname);
1279     }
1280     pmod->base_addr = base_addr;
1281     return 1;
1282   }
1283   return 0;
1284 }
1285 
1286 bool os::dll_address_to_library_name(address addr, char* buf,
1287                                      int buflen, int* offset) {
1288   // buf is not optional, but offset is optional
1289   assert(buf != NULL, "sanity check");
1290 
1291 // NOTE: the reason we don't use SymGetModuleInfo() is it doesn't always
1292 //       return the full path to the DLL file, sometimes it returns path
1293 //       to the corresponding PDB file (debug info); sometimes it only
1294 //       returns partial path, which makes life painful.
1295 
1296   struct _modinfo mi;
1297   mi.addr      = addr;
1298   mi.full_path = buf;
1299   mi.buflen    = buflen;
1300   if (get_loaded_modules_info(_locate_module_by_addr, (void *)&mi)) {
1301     // buf already contains path name
1302     if (offset) *offset = addr - mi.base_addr;
1303     return true;
1304   }
1305 
1306   buf[0] = '\0';
1307   if (offset) *offset = -1;
1308   return false;
1309 }
1310 
1311 bool os::dll_address_to_function_name(address addr, char *buf,
1312                                       int buflen, int *offset,
1313                                       bool demangle) {
1314   // buf is not optional, but offset is optional
1315   assert(buf != NULL, "sanity check");
1316 
1317   if (Decoder::decode(addr, buf, buflen, offset, demangle)) {
1318     return true;
1319   }
1320   if (offset != NULL)  *offset  = -1;
1321   buf[0] = '\0';
1322   return false;
1323 }
1324 
1325 // save the start and end address of jvm.dll into param[0] and param[1]
1326 static int _locate_jvm_dll(const char* mod_fname, address base_addr,
1327                            address top_address, void * param) {
1328   if (!param) return -1;
1329 
1330   if (base_addr   <= (address)_locate_jvm_dll &&
1331       top_address > (address)_locate_jvm_dll) {
1332     ((address*)param)[0] = base_addr;
1333     ((address*)param)[1] = top_address;
1334     return 1;
1335   }
1336   return 0;
1337 }
1338 
1339 address vm_lib_location[2];    // start and end address of jvm.dll
1340 
1341 // check if addr is inside jvm.dll
1342 bool os::address_is_in_vm(address addr) {
1343   if (!vm_lib_location[0] || !vm_lib_location[1]) {
1344     if (!get_loaded_modules_info(_locate_jvm_dll, (void *)vm_lib_location)) {
1345       assert(false, "Can't find jvm module.");
1346       return false;
1347     }
1348   }
1349 
1350   return (vm_lib_location[0] <= addr) && (addr < vm_lib_location[1]);
1351 }
1352 
1353 // print module info; param is outputStream*
1354 static int _print_module(const char* fname, address base_address,
1355                          address top_address, void* param) {
1356   if (!param) return -1;
1357 
1358   outputStream* st = (outputStream*)param;
1359 
1360   st->print(PTR_FORMAT " - " PTR_FORMAT " \t%s\n", base_address, top_address, fname);
1361   return 0;
1362 }
1363 
1364 // Loads .dll/.so and
1365 // in case of error it checks if .dll/.so was built for the
1366 // same architecture as Hotspot is running on
1367 void * os::dll_load(const char *name, char *ebuf, int ebuflen) {
1368   log_info(os)("attempting shared library load of %s", name);
1369 
1370   void * result = LoadLibrary(name);
1371   if (result != NULL) {
1372     Events::log(NULL, "Loaded shared library %s", name);
1373     // Recalculate pdb search path if a DLL was loaded successfully.
1374     SymbolEngine::recalc_search_path();
1375     log_info(os)("shared library load of %s was successful", name);
1376     return result;
1377   }
1378   DWORD errcode = GetLastError();
1379   // Read system error message into ebuf
1380   // It may or may not be overwritten below (in the for loop and just above)
1381   lasterror(ebuf, (size_t) ebuflen);
1382   ebuf[ebuflen - 1] = '\0';
1383   Events::log(NULL, "Loading shared library %s failed, error code %lu", name, errcode);
1384   log_info(os)("shared library load of %s failed, error code %lu", name, errcode);
1385 
1386   if (errcode == ERROR_MOD_NOT_FOUND) {
1387     strncpy(ebuf, "Can't find dependent libraries", ebuflen - 1);
1388     ebuf[ebuflen - 1] = '\0';
1389     return NULL;
1390   }
1391 
1392   // Parsing dll below
1393   // If we can read dll-info and find that dll was built
1394   // for an architecture other than Hotspot is running in
1395   // - then print to buffer "DLL was built for a different architecture"
1396   // else call os::lasterror to obtain system error message
1397   int fd = ::open(name, O_RDONLY | O_BINARY, 0);
1398   if (fd < 0) {
1399     return NULL;
1400   }
1401 
1402   uint32_t signature_offset;
1403   uint16_t lib_arch = 0;
1404   bool failed_to_get_lib_arch =
1405     ( // Go to position 3c in the dll
1406      (os::seek_to_file_offset(fd, IMAGE_FILE_PTR_TO_SIGNATURE) < 0)
1407      ||
1408      // Read location of signature
1409      (sizeof(signature_offset) !=
1410      (os::read(fd, (void*)&signature_offset, sizeof(signature_offset))))
1411      ||
1412      // Go to COFF File Header in dll
1413      // that is located after "signature" (4 bytes long)
1414      (os::seek_to_file_offset(fd,
1415      signature_offset + IMAGE_FILE_SIGNATURE_LENGTH) < 0)
1416      ||
1417      // Read field that contains code of architecture
1418      // that dll was built for
1419      (sizeof(lib_arch) != (os::read(fd, (void*)&lib_arch, sizeof(lib_arch))))
1420     );
1421 
1422   ::close(fd);
1423   if (failed_to_get_lib_arch) {
1424     // file i/o error - report os::lasterror(...) msg
1425     return NULL;
1426   }
1427 
1428   typedef struct {
1429     uint16_t arch_code;
1430     char* arch_name;
1431   } arch_t;
1432 
1433   static const arch_t arch_array[] = {
1434     {IMAGE_FILE_MACHINE_I386,      (char*)"IA 32"},
1435     {IMAGE_FILE_MACHINE_AMD64,     (char*)"AMD 64"}
1436   };
1437 #if (defined _M_AMD64)
1438   static const uint16_t running_arch = IMAGE_FILE_MACHINE_AMD64;
1439 #elif (defined _M_IX86)
1440   static const uint16_t running_arch = IMAGE_FILE_MACHINE_I386;
1441 #else
1442   #error Method os::dll_load requires that one of following \
1443          is defined :_M_AMD64 or _M_IX86
1444 #endif
1445 
1446 
1447   // Obtain a string for printf operation
1448   // lib_arch_str shall contain string what platform this .dll was built for
1449   // running_arch_str shall string contain what platform Hotspot was built for
1450   char *running_arch_str = NULL, *lib_arch_str = NULL;
1451   for (unsigned int i = 0; i < ARRAY_SIZE(arch_array); i++) {
1452     if (lib_arch == arch_array[i].arch_code) {
1453       lib_arch_str = arch_array[i].arch_name;
1454     }
1455     if (running_arch == arch_array[i].arch_code) {
1456       running_arch_str = arch_array[i].arch_name;
1457     }
1458   }
1459 
1460   assert(running_arch_str,
1461          "Didn't find running architecture code in arch_array");
1462 
1463   // If the architecture is right
1464   // but some other error took place - report os::lasterror(...) msg
1465   if (lib_arch == running_arch) {
1466     return NULL;
1467   }
1468 
1469   if (lib_arch_str != NULL) {
1470     ::_snprintf(ebuf, ebuflen - 1,
1471                 "Can't load %s-bit .dll on a %s-bit platform",
1472                 lib_arch_str, running_arch_str);
1473   } else {
1474     // don't know what architecture this dll was build for
1475     ::_snprintf(ebuf, ebuflen - 1,
1476                 "Can't load this .dll (machine code=0x%x) on a %s-bit platform",
1477                 lib_arch, running_arch_str);
1478   }
1479 
1480   return NULL;
1481 }
1482 
1483 void os::print_dll_info(outputStream *st) {
1484   st->print_cr("Dynamic libraries:");
1485   get_loaded_modules_info(_print_module, (void *)st);
1486 }
1487 
1488 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1489   HANDLE   hProcess;
1490 
1491 # define MAX_NUM_MODULES 128
1492   HMODULE     modules[MAX_NUM_MODULES];
1493   static char filename[MAX_PATH];
1494   int         result = 0;
1495 
1496   int pid = os::current_process_id();
1497   hProcess = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ,
1498                          FALSE, pid);
1499   if (hProcess == NULL) return 0;
1500 
1501   DWORD size_needed;
1502   if (!EnumProcessModules(hProcess, modules, sizeof(modules), &size_needed)) {
1503     CloseHandle(hProcess);
1504     return 0;
1505   }
1506 
1507   // number of modules that are currently loaded
1508   int num_modules = size_needed / sizeof(HMODULE);
1509 
1510   for (int i = 0; i < MIN2(num_modules, MAX_NUM_MODULES); i++) {
1511     // Get Full pathname:
1512     if (!GetModuleFileNameEx(hProcess, modules[i], filename, sizeof(filename))) {
1513       filename[0] = '\0';
1514     }
1515 
1516     MODULEINFO modinfo;
1517     if (!GetModuleInformation(hProcess, modules[i], &modinfo, sizeof(modinfo))) {
1518       modinfo.lpBaseOfDll = NULL;
1519       modinfo.SizeOfImage = 0;
1520     }
1521 
1522     // Invoke callback function
1523     result = callback(filename, (address)modinfo.lpBaseOfDll,
1524                       (address)((u8)modinfo.lpBaseOfDll + (u8)modinfo.SizeOfImage), param);
1525     if (result) break;
1526   }
1527 
1528   CloseHandle(hProcess);
1529   return result;
1530 }
1531 
1532 bool os::get_host_name(char* buf, size_t buflen) {
1533   DWORD size = (DWORD)buflen;
1534   return (GetComputerNameEx(ComputerNameDnsHostname, buf, &size) == TRUE);
1535 }
1536 
1537 void os::get_summary_os_info(char* buf, size_t buflen) {
1538   stringStream sst(buf, buflen);
1539   os::win32::print_windows_version(&sst);
1540   // chop off newline character
1541   char* nl = strchr(buf, '\n');
1542   if (nl != NULL) *nl = '\0';
1543 }
1544 
1545 int os::vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
1546 #if _MSC_VER >= 1900
1547   // Starting with Visual Studio 2015, vsnprint is C99 compliant.
1548   int result = ::vsnprintf(buf, len, fmt, args);
1549   // If an encoding error occurred (result < 0) then it's not clear
1550   // whether the buffer is NUL terminated, so ensure it is.
1551   if ((result < 0) && (len > 0)) {
1552     buf[len - 1] = '\0';
1553   }
1554   return result;
1555 #else
1556   // Before Visual Studio 2015, vsnprintf is not C99 compliant, so use
1557   // _vsnprintf, whose behavior seems to be *mostly* consistent across
1558   // versions.  However, when len == 0, avoid _vsnprintf too, and just
1559   // go straight to _vscprintf.  The output is going to be truncated in
1560   // that case, except in the unusual case of empty output.  More
1561   // importantly, the documentation for various versions of Visual Studio
1562   // are inconsistent about the behavior of _vsnprintf when len == 0,
1563   // including it possibly being an error.
1564   int result = -1;
1565   if (len > 0) {
1566     result = _vsnprintf(buf, len, fmt, args);
1567     // If output (including NUL terminator) is truncated, the buffer
1568     // won't be NUL terminated.  Add the trailing NUL specified by C99.
1569     if ((result < 0) || ((size_t)result >= len)) {
1570       buf[len - 1] = '\0';
1571     }
1572   }
1573   if (result < 0) {
1574     result = _vscprintf(fmt, args);
1575   }
1576   return result;
1577 #endif // _MSC_VER dispatch
1578 }
1579 
1580 static inline time_t get_mtime(const char* filename) {
1581   struct stat st;
1582   int ret = os::stat(filename, &st);
1583   assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
1584   return st.st_mtime;
1585 }
1586 
1587 int os::compare_file_modified_times(const char* file1, const char* file2) {
1588   time_t t1 = get_mtime(file1);
1589   time_t t2 = get_mtime(file2);
1590   return t1 - t2;
1591 }
1592 
1593 void os::print_os_info_brief(outputStream* st) {
1594   os::print_os_info(st);
1595 }
1596 
1597 void os::print_os_info(outputStream* st) {
1598 #ifdef ASSERT
1599   char buffer[1024];
1600   st->print("HostName: ");
1601   if (get_host_name(buffer, sizeof(buffer))) {
1602     st->print("%s ", buffer);
1603   } else {
1604     st->print("N/A ");
1605   }
1606 #endif
1607   st->print("OS:");
1608   os::win32::print_windows_version(st);
1609 
1610 #ifdef _LP64
1611   VM_Version::print_platform_virtualization_info(st);
1612 #endif
1613 }
1614 
1615 void os::win32::print_windows_version(outputStream* st) {
1616   OSVERSIONINFOEX osvi;
1617   VS_FIXEDFILEINFO *file_info;
1618   TCHAR kernel32_path[MAX_PATH];
1619   UINT len, ret;
1620 
1621   // Use the GetVersionEx information to see if we're on a server or
1622   // workstation edition of Windows. Starting with Windows 8.1 we can't
1623   // trust the OS version information returned by this API.
1624   ZeroMemory(&osvi, sizeof(OSVERSIONINFOEX));
1625   osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
1626   if (!GetVersionEx((OSVERSIONINFO *)&osvi)) {
1627     st->print_cr("Call to GetVersionEx failed");
1628     return;
1629   }
1630   bool is_workstation = (osvi.wProductType == VER_NT_WORKSTATION);
1631 
1632   // Get the full path to \Windows\System32\kernel32.dll and use that for
1633   // determining what version of Windows we're running on.
1634   len = MAX_PATH - (UINT)strlen("\\kernel32.dll") - 1;
1635   ret = GetSystemDirectory(kernel32_path, len);
1636   if (ret == 0 || ret > len) {
1637     st->print_cr("Call to GetSystemDirectory failed");
1638     return;
1639   }
1640   strncat(kernel32_path, "\\kernel32.dll", MAX_PATH - ret);
1641 
1642   DWORD version_size = GetFileVersionInfoSize(kernel32_path, NULL);
1643   if (version_size == 0) {
1644     st->print_cr("Call to GetFileVersionInfoSize failed");
1645     return;
1646   }
1647 
1648   LPTSTR version_info = (LPTSTR)os::malloc(version_size, mtInternal);
1649   if (version_info == NULL) {
1650     st->print_cr("Failed to allocate version_info");
1651     return;
1652   }
1653 
1654   if (!GetFileVersionInfo(kernel32_path, NULL, version_size, version_info)) {
1655     os::free(version_info);
1656     st->print_cr("Call to GetFileVersionInfo failed");
1657     return;
1658   }
1659 
1660   if (!VerQueryValue(version_info, TEXT("\\"), (LPVOID*)&file_info, &len)) {
1661     os::free(version_info);
1662     st->print_cr("Call to VerQueryValue failed");
1663     return;
1664   }
1665 
1666   int major_version = HIWORD(file_info->dwProductVersionMS);
1667   int minor_version = LOWORD(file_info->dwProductVersionMS);
1668   int build_number = HIWORD(file_info->dwProductVersionLS);
1669   int build_minor = LOWORD(file_info->dwProductVersionLS);
1670   int os_vers = major_version * 1000 + minor_version;
1671   os::free(version_info);
1672 
1673   st->print(" Windows ");
1674   switch (os_vers) {
1675 
1676   case 6000:
1677     if (is_workstation) {
1678       st->print("Vista");
1679     } else {
1680       st->print("Server 2008");
1681     }
1682     break;
1683 
1684   case 6001:
1685     if (is_workstation) {
1686       st->print("7");
1687     } else {
1688       st->print("Server 2008 R2");
1689     }
1690     break;
1691 
1692   case 6002:
1693     if (is_workstation) {
1694       st->print("8");
1695     } else {
1696       st->print("Server 2012");
1697     }
1698     break;
1699 
1700   case 6003:
1701     if (is_workstation) {
1702       st->print("8.1");
1703     } else {
1704       st->print("Server 2012 R2");
1705     }
1706     break;
1707 
1708   case 10000:
1709     if (is_workstation) {
1710       st->print("10");
1711     } else {
1712       // distinguish Windows Server 2016 and 2019 by build number
1713       // Windows server 2019 GA 10/2018 build number is 17763
1714       if (build_number > 17762) {
1715         st->print("Server 2019");
1716       } else {
1717         st->print("Server 2016");
1718       }
1719     }
1720     break;
1721 
1722   default:
1723     // Unrecognized windows, print out its major and minor versions
1724     st->print("%d.%d", major_version, minor_version);
1725     break;
1726   }
1727 
1728   // Retrieve SYSTEM_INFO from GetNativeSystemInfo call so that we could
1729   // find out whether we are running on 64 bit processor or not
1730   SYSTEM_INFO si;
1731   ZeroMemory(&si, sizeof(SYSTEM_INFO));
1732   GetNativeSystemInfo(&si);
1733   if (si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_AMD64) {
1734     st->print(" , 64 bit");
1735   }
1736 
1737   st->print(" Build %d", build_number);
1738   st->print(" (%d.%d.%d.%d)", major_version, minor_version, build_number, build_minor);
1739   st->cr();
1740 }
1741 
1742 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1743   // Nothing to do for now.
1744 }
1745 
1746 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1747   HKEY key;
1748   DWORD status = RegOpenKey(HKEY_LOCAL_MACHINE,
1749                "HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0", &key);
1750   if (status == ERROR_SUCCESS) {
1751     DWORD size = (DWORD)buflen;
1752     status = RegQueryValueEx(key, "ProcessorNameString", NULL, NULL, (byte*)buf, &size);
1753     if (status != ERROR_SUCCESS) {
1754         strncpy(buf, "## __CPU__", buflen);
1755     }
1756     RegCloseKey(key);
1757   } else {
1758     // Put generic cpu info to return
1759     strncpy(buf, "## __CPU__", buflen);
1760   }
1761 }
1762 
1763 void os::print_memory_info(outputStream* st) {
1764   st->print("Memory:");
1765   st->print(" %dk page", os::vm_page_size()>>10);
1766 
1767   // Use GlobalMemoryStatusEx() because GlobalMemoryStatus() may return incorrect
1768   // value if total memory is larger than 4GB
1769   MEMORYSTATUSEX ms;
1770   ms.dwLength = sizeof(ms);
1771   int r1 = GlobalMemoryStatusEx(&ms);
1772 
1773   if (r1 != 0) {
1774     st->print(", system-wide physical " INT64_FORMAT "M ",
1775              (int64_t) ms.ullTotalPhys >> 20);
1776     st->print("(" INT64_FORMAT "M free)\n", (int64_t) ms.ullAvailPhys >> 20);
1777 
1778     st->print("TotalPageFile size " INT64_FORMAT "M ",
1779              (int64_t) ms.ullTotalPageFile >> 20);
1780     st->print("(AvailPageFile size " INT64_FORMAT "M)",
1781              (int64_t) ms.ullAvailPageFile >> 20);
1782 
1783     // on 32bit Total/AvailVirtual are interesting (show us how close we get to 2-4 GB per process borders)
1784 #if defined(_M_IX86)
1785     st->print(", user-mode portion of virtual address-space " INT64_FORMAT "M ",
1786              (int64_t) ms.ullTotalVirtual >> 20);
1787     st->print("(" INT64_FORMAT "M free)", (int64_t) ms.ullAvailVirtual >> 20);
1788 #endif
1789   } else {
1790     st->print(", GlobalMemoryStatusEx did not succeed so we miss some memory values.");
1791   }
1792 
1793   // extended memory statistics for a process
1794   PROCESS_MEMORY_COUNTERS_EX pmex;
1795   ZeroMemory(&pmex, sizeof(PROCESS_MEMORY_COUNTERS_EX));
1796   pmex.cb = sizeof(pmex);
1797   int r2 = GetProcessMemoryInfo(GetCurrentProcess(), (PROCESS_MEMORY_COUNTERS*) &pmex, sizeof(pmex));
1798 
1799   if (r2 != 0) {
1800     st->print("\ncurrent process WorkingSet (physical memory assigned to process): " INT64_FORMAT "M, ",
1801              (int64_t) pmex.WorkingSetSize >> 20);
1802     st->print("peak: " INT64_FORMAT "M\n", (int64_t) pmex.PeakWorkingSetSize >> 20);
1803 
1804     st->print("current process commit charge (\"private bytes\"): " INT64_FORMAT "M, ",
1805              (int64_t) pmex.PrivateUsage >> 20);
1806     st->print("peak: " INT64_FORMAT "M", (int64_t) pmex.PeakPagefileUsage >> 20);
1807   } else {
1808     st->print("\nGetProcessMemoryInfo did not succeed so we miss some memory values.");
1809   }
1810 
1811   st->cr();
1812 }
1813 
1814 bool os::signal_sent_by_kill(const void* siginfo) {
1815   // TODO: Is this possible?
1816   return false;
1817 }
1818 
1819 void os::print_siginfo(outputStream *st, const void* siginfo) {
1820   const EXCEPTION_RECORD* const er = (EXCEPTION_RECORD*)siginfo;
1821   st->print("siginfo:");
1822 
1823   char tmp[64];
1824   if (os::exception_name(er->ExceptionCode, tmp, sizeof(tmp)) == NULL) {
1825     strcpy(tmp, "EXCEPTION_??");
1826   }
1827   st->print(" %s (0x%x)", tmp, er->ExceptionCode);
1828 
1829   if ((er->ExceptionCode == EXCEPTION_ACCESS_VIOLATION ||
1830        er->ExceptionCode == EXCEPTION_IN_PAGE_ERROR) &&
1831        er->NumberParameters >= 2) {
1832     switch (er->ExceptionInformation[0]) {
1833     case 0: st->print(", reading address"); break;
1834     case 1: st->print(", writing address"); break;
1835     case 8: st->print(", data execution prevention violation at address"); break;
1836     default: st->print(", ExceptionInformation=" INTPTR_FORMAT,
1837                        er->ExceptionInformation[0]);
1838     }
1839     st->print(" " INTPTR_FORMAT, er->ExceptionInformation[1]);
1840   } else {
1841     int num = er->NumberParameters;
1842     if (num > 0) {
1843       st->print(", ExceptionInformation=");
1844       for (int i = 0; i < num; i++) {
1845         st->print(INTPTR_FORMAT " ", er->ExceptionInformation[i]);
1846       }
1847     }
1848   }
1849   st->cr();
1850 }
1851 
1852 bool os::signal_thread(Thread* thread, int sig, const char* reason) {
1853   // TODO: Can we kill thread?
1854   return false;
1855 }
1856 
1857 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1858   // do nothing
1859 }
1860 
1861 static char saved_jvm_path[MAX_PATH] = {0};
1862 
1863 // Find the full path to the current module, jvm.dll
1864 void os::jvm_path(char *buf, jint buflen) {
1865   // Error checking.
1866   if (buflen < MAX_PATH) {
1867     assert(false, "must use a large-enough buffer");
1868     buf[0] = '\0';
1869     return;
1870   }
1871   // Lazy resolve the path to current module.
1872   if (saved_jvm_path[0] != 0) {
1873     strcpy(buf, saved_jvm_path);
1874     return;
1875   }
1876 
1877   buf[0] = '\0';
1878   if (Arguments::sun_java_launcher_is_altjvm()) {
1879     // Support for the java launcher's '-XXaltjvm=<path>' option. Check
1880     // for a JAVA_HOME environment variable and fix up the path so it
1881     // looks like jvm.dll is installed there (append a fake suffix
1882     // hotspot/jvm.dll).
1883     char* java_home_var = ::getenv("JAVA_HOME");
1884     if (java_home_var != NULL && java_home_var[0] != 0 &&
1885         strlen(java_home_var) < (size_t)buflen) {
1886       strncpy(buf, java_home_var, buflen);
1887 
1888       // determine if this is a legacy image or modules image
1889       // modules image doesn't have "jre" subdirectory
1890       size_t len = strlen(buf);
1891       char* jrebin_p = buf + len;
1892       jio_snprintf(jrebin_p, buflen-len, "\\jre\\bin\\");
1893       if (0 != _access(buf, 0)) {
1894         jio_snprintf(jrebin_p, buflen-len, "\\bin\\");
1895       }
1896       len = strlen(buf);
1897       jio_snprintf(buf + len, buflen-len, "hotspot\\jvm.dll");
1898     }
1899   }
1900 
1901   if (buf[0] == '\0') {
1902     GetModuleFileName(vm_lib_handle, buf, buflen);
1903   }
1904   strncpy(saved_jvm_path, buf, MAX_PATH);
1905   saved_jvm_path[MAX_PATH - 1] = '\0';
1906 }
1907 
1908 
1909 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1910 #ifndef _WIN64
1911   st->print("_");
1912 #endif
1913 }
1914 
1915 
1916 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1917 #ifndef _WIN64
1918   st->print("@%d", args_size  * sizeof(int));
1919 #endif
1920 }
1921 
1922 // This method is a copy of JDK's sysGetLastErrorString
1923 // from src/windows/hpi/src/system_md.c
1924 
1925 size_t os::lasterror(char* buf, size_t len) {
1926   DWORD errval;
1927 
1928   if ((errval = GetLastError()) != 0) {
1929     // DOS error
1930     size_t n = (size_t)FormatMessage(
1931                                      FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,
1932                                      NULL,
1933                                      errval,
1934                                      0,
1935                                      buf,
1936                                      (DWORD)len,
1937                                      NULL);
1938     if (n > 3) {
1939       // Drop final '.', CR, LF
1940       if (buf[n - 1] == '\n') n--;
1941       if (buf[n - 1] == '\r') n--;
1942       if (buf[n - 1] == '.') n--;
1943       buf[n] = '\0';
1944     }
1945     return n;
1946   }
1947 
1948   if (errno != 0) {
1949     // C runtime error that has no corresponding DOS error code
1950     const char* s = os::strerror(errno);
1951     size_t n = strlen(s);
1952     if (n >= len) n = len - 1;
1953     strncpy(buf, s, n);
1954     buf[n] = '\0';
1955     return n;
1956   }
1957 
1958   return 0;
1959 }
1960 
1961 int os::get_last_error() {
1962   DWORD error = GetLastError();
1963   if (error == 0) {
1964     error = errno;
1965   }
1966   return (int)error;
1967 }
1968 
1969 // sun.misc.Signal
1970 // NOTE that this is a workaround for an apparent kernel bug where if
1971 // a signal handler for SIGBREAK is installed then that signal handler
1972 // takes priority over the console control handler for CTRL_CLOSE_EVENT.
1973 // See bug 4416763.
1974 static void (*sigbreakHandler)(int) = NULL;
1975 
1976 static void UserHandler(int sig, void *siginfo, void *context) {
1977   os::signal_notify(sig);
1978   // We need to reinstate the signal handler each time...
1979   os::signal(sig, (void*)UserHandler);
1980 }
1981 
1982 void* os::user_handler() {
1983   return (void*) UserHandler;
1984 }
1985 
1986 void* os::signal(int signal_number, void* handler) {
1987   if ((signal_number == SIGBREAK) && (!ReduceSignalUsage)) {
1988     void (*oldHandler)(int) = sigbreakHandler;
1989     sigbreakHandler = (void (*)(int)) handler;
1990     return (void*) oldHandler;
1991   } else {
1992     return (void*)::signal(signal_number, (void (*)(int))handler);
1993   }
1994 }
1995 
1996 void os::signal_raise(int signal_number) {
1997   raise(signal_number);
1998 }
1999 
2000 // The Win32 C runtime library maps all console control events other than ^C
2001 // into SIGBREAK, which makes it impossible to distinguish ^BREAK from close,
2002 // logoff, and shutdown events.  We therefore install our own console handler
2003 // that raises SIGTERM for the latter cases.
2004 //
2005 static BOOL WINAPI consoleHandler(DWORD event) {
2006   switch (event) {
2007   case CTRL_C_EVENT:
2008     if (VMError::is_error_reported()) {
2009       // Ctrl-C is pressed during error reporting, likely because the error
2010       // handler fails to abort. Let VM die immediately.
2011       os::die();
2012     }
2013 
2014     os::signal_raise(SIGINT);
2015     return TRUE;
2016     break;
2017   case CTRL_BREAK_EVENT:
2018     if (sigbreakHandler != NULL) {
2019       (*sigbreakHandler)(SIGBREAK);
2020     }
2021     return TRUE;
2022     break;
2023   case CTRL_LOGOFF_EVENT: {
2024     // Don't terminate JVM if it is running in a non-interactive session,
2025     // such as a service process.
2026     USEROBJECTFLAGS flags;
2027     HANDLE handle = GetProcessWindowStation();
2028     if (handle != NULL &&
2029         GetUserObjectInformation(handle, UOI_FLAGS, &flags,
2030         sizeof(USEROBJECTFLAGS), NULL)) {
2031       // If it is a non-interactive session, let next handler to deal
2032       // with it.
2033       if ((flags.dwFlags & WSF_VISIBLE) == 0) {
2034         return FALSE;
2035       }
2036     }
2037   }
2038   case CTRL_CLOSE_EVENT:
2039   case CTRL_SHUTDOWN_EVENT:
2040     os::signal_raise(SIGTERM);
2041     return TRUE;
2042     break;
2043   default:
2044     break;
2045   }
2046   return FALSE;
2047 }
2048 
2049 // The following code is moved from os.cpp for making this
2050 // code platform specific, which it is by its very nature.
2051 
2052 // Return maximum OS signal used + 1 for internal use only
2053 // Used as exit signal for signal_thread
2054 int os::sigexitnum_pd() {
2055   return NSIG;
2056 }
2057 
2058 // a counter for each possible signal value, including signal_thread exit signal
2059 static volatile jint pending_signals[NSIG+1] = { 0 };
2060 static Semaphore* sig_sem = NULL;
2061 
2062 static void jdk_misc_signal_init() {
2063   // Initialize signal structures
2064   memset((void*)pending_signals, 0, sizeof(pending_signals));
2065 
2066   // Initialize signal semaphore
2067   sig_sem = new Semaphore();
2068 
2069   // Programs embedding the VM do not want it to attempt to receive
2070   // events like CTRL_LOGOFF_EVENT, which are used to implement the
2071   // shutdown hooks mechanism introduced in 1.3.  For example, when
2072   // the VM is run as part of a Windows NT service (i.e., a servlet
2073   // engine in a web server), the correct behavior is for any console
2074   // control handler to return FALSE, not TRUE, because the OS's
2075   // "final" handler for such events allows the process to continue if
2076   // it is a service (while terminating it if it is not a service).
2077   // To make this behavior uniform and the mechanism simpler, we
2078   // completely disable the VM's usage of these console events if -Xrs
2079   // (=ReduceSignalUsage) is specified.  This means, for example, that
2080   // the CTRL-BREAK thread dump mechanism is also disabled in this
2081   // case.  See bugs 4323062, 4345157, and related bugs.
2082 
2083   // Add a CTRL-C handler
2084   SetConsoleCtrlHandler(consoleHandler, TRUE);
2085 }
2086 
2087 void os::signal_notify(int sig) {
2088   if (sig_sem != NULL) {
2089     Atomic::inc(&pending_signals[sig]);
2090     sig_sem->signal();
2091   } else {
2092     // Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init
2093     // initialization isn't called.
2094     assert(ReduceSignalUsage, "signal semaphore should be created");
2095   }
2096 }
2097 
2098 static int check_pending_signals() {
2099   while (true) {
2100     for (int i = 0; i < NSIG + 1; i++) {
2101       jint n = pending_signals[i];
2102       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2103         return i;
2104       }
2105     }
2106     JavaThread *thread = JavaThread::current();
2107 
2108     ThreadBlockInVM tbivm(thread);
2109 
2110     bool threadIsSuspended;
2111     do {
2112       thread->set_suspend_equivalent();
2113       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2114       sig_sem->wait();
2115 
2116       // were we externally suspended while we were waiting?
2117       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2118       if (threadIsSuspended) {
2119         // The semaphore has been incremented, but while we were waiting
2120         // another thread suspended us. We don't want to continue running
2121         // while suspended because that would surprise the thread that
2122         // suspended us.
2123         sig_sem->signal();
2124 
2125         thread->java_suspend_self();
2126       }
2127     } while (threadIsSuspended);
2128   }
2129 }
2130 
2131 int os::signal_wait() {
2132   return check_pending_signals();
2133 }
2134 
2135 // Implicit OS exception handling
2136 
2137 LONG Handle_Exception(struct _EXCEPTION_POINTERS* exceptionInfo,
2138                       address handler) {
2139   JavaThread* thread = (JavaThread*) Thread::current_or_null();
2140   // Save pc in thread
2141 #ifdef _M_AMD64
2142   // Do not blow up if no thread info available.
2143   if (thread) {
2144     thread->set_saved_exception_pc((address)(DWORD_PTR)exceptionInfo->ContextRecord->Rip);
2145   }
2146   // Set pc to handler
2147   exceptionInfo->ContextRecord->Rip = (DWORD64)handler;
2148 #else
2149   // Do not blow up if no thread info available.
2150   if (thread) {
2151     thread->set_saved_exception_pc((address)(DWORD_PTR)exceptionInfo->ContextRecord->Eip);
2152   }
2153   // Set pc to handler
2154   exceptionInfo->ContextRecord->Eip = (DWORD)(DWORD_PTR)handler;
2155 #endif
2156 
2157   // Continue the execution
2158   return EXCEPTION_CONTINUE_EXECUTION;
2159 }
2160 
2161 
2162 // Used for PostMortemDump
2163 extern "C" void safepoints();
2164 extern "C" void find(int x);
2165 extern "C" void events();
2166 
2167 // According to Windows API documentation, an illegal instruction sequence should generate
2168 // the 0xC000001C exception code. However, real world experience shows that occasionnaly
2169 // the execution of an illegal instruction can generate the exception code 0xC000001E. This
2170 // seems to be an undocumented feature of Win NT 4.0 (and probably other Windows systems).
2171 
2172 #define EXCEPTION_ILLEGAL_INSTRUCTION_2 0xC000001E
2173 
2174 // From "Execution Protection in the Windows Operating System" draft 0.35
2175 // Once a system header becomes available, the "real" define should be
2176 // included or copied here.
2177 #define EXCEPTION_INFO_EXEC_VIOLATION 0x08
2178 
2179 // Windows Vista/2008 heap corruption check
2180 #define EXCEPTION_HEAP_CORRUPTION        0xC0000374
2181 
2182 // All Visual C++ exceptions thrown from code generated by the Microsoft Visual
2183 // C++ compiler contain this error code. Because this is a compiler-generated
2184 // error, the code is not listed in the Win32 API header files.
2185 // The code is actually a cryptic mnemonic device, with the initial "E"
2186 // standing for "exception" and the final 3 bytes (0x6D7363) representing the
2187 // ASCII values of "msc".
2188 
2189 #define EXCEPTION_UNCAUGHT_CXX_EXCEPTION    0xE06D7363
2190 
2191 #define def_excpt(val) { #val, (val) }
2192 
2193 static const struct { const char* name; uint number; } exceptlabels[] = {
2194     def_excpt(EXCEPTION_ACCESS_VIOLATION),
2195     def_excpt(EXCEPTION_DATATYPE_MISALIGNMENT),
2196     def_excpt(EXCEPTION_BREAKPOINT),
2197     def_excpt(EXCEPTION_SINGLE_STEP),
2198     def_excpt(EXCEPTION_ARRAY_BOUNDS_EXCEEDED),
2199     def_excpt(EXCEPTION_FLT_DENORMAL_OPERAND),
2200     def_excpt(EXCEPTION_FLT_DIVIDE_BY_ZERO),
2201     def_excpt(EXCEPTION_FLT_INEXACT_RESULT),
2202     def_excpt(EXCEPTION_FLT_INVALID_OPERATION),
2203     def_excpt(EXCEPTION_FLT_OVERFLOW),
2204     def_excpt(EXCEPTION_FLT_STACK_CHECK),
2205     def_excpt(EXCEPTION_FLT_UNDERFLOW),
2206     def_excpt(EXCEPTION_INT_DIVIDE_BY_ZERO),
2207     def_excpt(EXCEPTION_INT_OVERFLOW),
2208     def_excpt(EXCEPTION_PRIV_INSTRUCTION),
2209     def_excpt(EXCEPTION_IN_PAGE_ERROR),
2210     def_excpt(EXCEPTION_ILLEGAL_INSTRUCTION),
2211     def_excpt(EXCEPTION_ILLEGAL_INSTRUCTION_2),
2212     def_excpt(EXCEPTION_NONCONTINUABLE_EXCEPTION),
2213     def_excpt(EXCEPTION_STACK_OVERFLOW),
2214     def_excpt(EXCEPTION_INVALID_DISPOSITION),
2215     def_excpt(EXCEPTION_GUARD_PAGE),
2216     def_excpt(EXCEPTION_INVALID_HANDLE),
2217     def_excpt(EXCEPTION_UNCAUGHT_CXX_EXCEPTION),
2218     def_excpt(EXCEPTION_HEAP_CORRUPTION)
2219 };
2220 
2221 #undef def_excpt
2222 
2223 const char* os::exception_name(int exception_code, char *buf, size_t size) {
2224   uint code = static_cast<uint>(exception_code);
2225   for (uint i = 0; i < ARRAY_SIZE(exceptlabels); ++i) {
2226     if (exceptlabels[i].number == code) {
2227       jio_snprintf(buf, size, "%s", exceptlabels[i].name);
2228       return buf;
2229     }
2230   }
2231 
2232   return NULL;
2233 }
2234 
2235 //-----------------------------------------------------------------------------
2236 LONG Handle_IDiv_Exception(struct _EXCEPTION_POINTERS* exceptionInfo) {
2237   // handle exception caused by idiv; should only happen for -MinInt/-1
2238   // (division by zero is handled explicitly)
2239 #ifdef  _M_AMD64
2240   PCONTEXT ctx = exceptionInfo->ContextRecord;
2241   address pc = (address)ctx->Rip;
2242   assert(pc[0] >= Assembler::REX && pc[0] <= Assembler::REX_WRXB && pc[1] == 0xF7 || pc[0] == 0xF7, "not an idiv opcode");
2243   assert(pc[0] >= Assembler::REX && pc[0] <= Assembler::REX_WRXB && (pc[2] & ~0x7) == 0xF8 || (pc[1] & ~0x7) == 0xF8, "cannot handle non-register operands");
2244   if (pc[0] == 0xF7) {
2245     // set correct result values and continue after idiv instruction
2246     ctx->Rip = (DWORD64)pc + 2;        // idiv reg, reg  is 2 bytes
2247   } else {
2248     ctx->Rip = (DWORD64)pc + 3;        // REX idiv reg, reg  is 3 bytes
2249   }
2250   // Do not set ctx->Rax as it already contains the correct value (either 32 or 64 bit, depending on the operation)
2251   // this is the case because the exception only happens for -MinValue/-1 and -MinValue is always in rax because of the
2252   // idiv opcode (0xF7).
2253   ctx->Rdx = (DWORD)0;             // remainder
2254   // Continue the execution
2255 #else
2256   PCONTEXT ctx = exceptionInfo->ContextRecord;
2257   address pc = (address)ctx->Eip;
2258   assert(pc[0] == 0xF7, "not an idiv opcode");
2259   assert((pc[1] & ~0x7) == 0xF8, "cannot handle non-register operands");
2260   assert(ctx->Eax == min_jint, "unexpected idiv exception");
2261   // set correct result values and continue after idiv instruction
2262   ctx->Eip = (DWORD)pc + 2;        // idiv reg, reg  is 2 bytes
2263   ctx->Eax = (DWORD)min_jint;      // result
2264   ctx->Edx = (DWORD)0;             // remainder
2265   // Continue the execution
2266 #endif
2267   return EXCEPTION_CONTINUE_EXECUTION;
2268 }
2269 
2270 //-----------------------------------------------------------------------------
2271 LONG WINAPI Handle_FLT_Exception(struct _EXCEPTION_POINTERS* exceptionInfo) {
2272   PCONTEXT ctx = exceptionInfo->ContextRecord;
2273 #ifndef  _WIN64
2274   // handle exception caused by native method modifying control word
2275   DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode;
2276 
2277   switch (exception_code) {
2278   case EXCEPTION_FLT_DENORMAL_OPERAND:
2279   case EXCEPTION_FLT_DIVIDE_BY_ZERO:
2280   case EXCEPTION_FLT_INEXACT_RESULT:
2281   case EXCEPTION_FLT_INVALID_OPERATION:
2282   case EXCEPTION_FLT_OVERFLOW:
2283   case EXCEPTION_FLT_STACK_CHECK:
2284   case EXCEPTION_FLT_UNDERFLOW:
2285     jint fp_control_word = (* (jint*) StubRoutines::addr_fpu_cntrl_wrd_std());
2286     if (fp_control_word != ctx->FloatSave.ControlWord) {
2287       // Restore FPCW and mask out FLT exceptions
2288       ctx->FloatSave.ControlWord = fp_control_word | 0xffffffc0;
2289       // Mask out pending FLT exceptions
2290       ctx->FloatSave.StatusWord &=  0xffffff00;
2291       return EXCEPTION_CONTINUE_EXECUTION;
2292     }
2293   }
2294 
2295   if (prev_uef_handler != NULL) {
2296     // We didn't handle this exception so pass it to the previous
2297     // UnhandledExceptionFilter.
2298     return (prev_uef_handler)(exceptionInfo);
2299   }
2300 #else // !_WIN64
2301   // On Windows, the mxcsr control bits are non-volatile across calls
2302   // See also CR 6192333
2303   //
2304   jint MxCsr = INITIAL_MXCSR;
2305   // we can't use StubRoutines::addr_mxcsr_std()
2306   // because in Win64 mxcsr is not saved there
2307   if (MxCsr != ctx->MxCsr) {
2308     ctx->MxCsr = MxCsr;
2309     return EXCEPTION_CONTINUE_EXECUTION;
2310   }
2311 #endif // !_WIN64
2312 
2313   return EXCEPTION_CONTINUE_SEARCH;
2314 }
2315 
2316 static inline void report_error(Thread* t, DWORD exception_code,
2317                                 address addr, void* siginfo, void* context) {
2318   VMError::report_and_die(t, exception_code, addr, siginfo, context);
2319 
2320   // If UseOsErrorReporting, this will return here and save the error file
2321   // somewhere where we can find it in the minidump.
2322 }
2323 
2324 bool os::win32::get_frame_at_stack_banging_point(JavaThread* thread,
2325         struct _EXCEPTION_POINTERS* exceptionInfo, address pc, frame* fr) {
2326   PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2327   address addr = (address) exceptionRecord->ExceptionInformation[1];
2328   if (Interpreter::contains(pc)) {
2329     *fr = os::fetch_frame_from_context((void*)exceptionInfo->ContextRecord);
2330     if (!fr->is_first_java_frame()) {
2331       // get_frame_at_stack_banging_point() is only called when we
2332       // have well defined stacks so java_sender() calls do not need
2333       // to assert safe_for_sender() first.
2334       *fr = fr->java_sender();
2335     }
2336   } else {
2337     // more complex code with compiled code
2338     assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
2339     CodeBlob* cb = CodeCache::find_blob(pc);
2340     if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
2341       // Not sure where the pc points to, fallback to default
2342       // stack overflow handling
2343       return false;
2344     } else {
2345       *fr = os::fetch_frame_from_context((void*)exceptionInfo->ContextRecord);
2346       // in compiled code, the stack banging is performed just after the return pc
2347       // has been pushed on the stack
2348       *fr = frame(fr->sp() + 1, fr->fp(), (address)*(fr->sp()));
2349       if (!fr->is_java_frame()) {
2350         // See java_sender() comment above.
2351         *fr = fr->java_sender();
2352       }
2353     }
2354   }
2355   assert(fr->is_java_frame(), "Safety check");
2356   return true;
2357 }
2358 
2359 #if INCLUDE_AOT
2360 LONG WINAPI topLevelVectoredExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
2361   PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2362   address addr = (address) exceptionRecord->ExceptionInformation[1];
2363   address pc = (address) exceptionInfo->ContextRecord->Rip;
2364 
2365   // Handle the case where we get an implicit exception in AOT generated
2366   // code.  AOT DLL's loaded are not registered for structured exceptions.
2367   // If the exception occurred in the codeCache or AOT code, pass control
2368   // to our normal exception handler.
2369   CodeBlob* cb = CodeCache::find_blob(pc);
2370   if (cb != NULL) {
2371     return topLevelExceptionFilter(exceptionInfo);
2372   }
2373 
2374   return EXCEPTION_CONTINUE_SEARCH;
2375 }
2376 #endif
2377 
2378 //-----------------------------------------------------------------------------
2379 LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
2380   if (InterceptOSException) return EXCEPTION_CONTINUE_SEARCH;
2381   DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode;
2382 #ifdef _M_AMD64
2383   address pc = (address) exceptionInfo->ContextRecord->Rip;
2384 #else
2385   address pc = (address) exceptionInfo->ContextRecord->Eip;
2386 #endif
2387   Thread* t = Thread::current_or_null_safe();
2388 
2389   // Handle SafeFetch32 and SafeFetchN exceptions.
2390   if (StubRoutines::is_safefetch_fault(pc)) {
2391     return Handle_Exception(exceptionInfo, StubRoutines::continuation_for_safefetch_fault(pc));
2392   }
2393 
2394 #ifndef _WIN64
2395   // Execution protection violation - win32 running on AMD64 only
2396   // Handled first to avoid misdiagnosis as a "normal" access violation;
2397   // This is safe to do because we have a new/unique ExceptionInformation
2398   // code for this condition.
2399   if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2400     PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2401     int exception_subcode = (int) exceptionRecord->ExceptionInformation[0];
2402     address addr = (address) exceptionRecord->ExceptionInformation[1];
2403 
2404     if (exception_subcode == EXCEPTION_INFO_EXEC_VIOLATION) {
2405       int page_size = os::vm_page_size();
2406 
2407       // Make sure the pc and the faulting address are sane.
2408       //
2409       // If an instruction spans a page boundary, and the page containing
2410       // the beginning of the instruction is executable but the following
2411       // page is not, the pc and the faulting address might be slightly
2412       // different - we still want to unguard the 2nd page in this case.
2413       //
2414       // 15 bytes seems to be a (very) safe value for max instruction size.
2415       bool pc_is_near_addr =
2416         (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
2417       bool instr_spans_page_boundary =
2418         (align_down((intptr_t) pc ^ (intptr_t) addr,
2419                          (intptr_t) page_size) > 0);
2420 
2421       if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
2422         static volatile address last_addr =
2423           (address) os::non_memory_address_word();
2424 
2425         // In conservative mode, don't unguard unless the address is in the VM
2426         if (UnguardOnExecutionViolation > 0 && addr != last_addr &&
2427             (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
2428 
2429           // Set memory to RWX and retry
2430           address page_start = align_down(addr, page_size);
2431           bool res = os::protect_memory((char*) page_start, page_size,
2432                                         os::MEM_PROT_RWX);
2433 
2434           log_debug(os)("Execution protection violation "
2435                         "at " INTPTR_FORMAT
2436                         ", unguarding " INTPTR_FORMAT ": %s", p2i(addr),
2437                         p2i(page_start), (res ? "success" : os::strerror(errno)));
2438 
2439           // Set last_addr so if we fault again at the same address, we don't
2440           // end up in an endless loop.
2441           //
2442           // There are two potential complications here.  Two threads trapping
2443           // at the same address at the same time could cause one of the
2444           // threads to think it already unguarded, and abort the VM.  Likely
2445           // very rare.
2446           //
2447           // The other race involves two threads alternately trapping at
2448           // different addresses and failing to unguard the page, resulting in
2449           // an endless loop.  This condition is probably even more unlikely
2450           // than the first.
2451           //
2452           // Although both cases could be avoided by using locks or thread
2453           // local last_addr, these solutions are unnecessary complication:
2454           // this handler is a best-effort safety net, not a complete solution.
2455           // It is disabled by default and should only be used as a workaround
2456           // in case we missed any no-execute-unsafe VM code.
2457 
2458           last_addr = addr;
2459 
2460           return EXCEPTION_CONTINUE_EXECUTION;
2461         }
2462       }
2463 
2464       // Last unguard failed or not unguarding
2465       tty->print_raw_cr("Execution protection violation");
2466       report_error(t, exception_code, addr, exceptionInfo->ExceptionRecord,
2467                    exceptionInfo->ContextRecord);
2468       return EXCEPTION_CONTINUE_SEARCH;
2469     }
2470   }
2471 #endif // _WIN64
2472 
2473   if ((exception_code == EXCEPTION_ACCESS_VIOLATION) &&
2474       VM_Version::is_cpuinfo_segv_addr(pc)) {
2475     // Verify that OS save/restore AVX registers.
2476     return Handle_Exception(exceptionInfo, VM_Version::cpuinfo_cont_addr());
2477   }
2478 
2479   if (t != NULL && t->is_Java_thread()) {
2480     JavaThread* thread = (JavaThread*) t;
2481     bool in_java = thread->thread_state() == _thread_in_Java;
2482 
2483     // Handle potential stack overflows up front.
2484     if (exception_code == EXCEPTION_STACK_OVERFLOW) {
2485       if (thread->stack_guards_enabled()) {
2486         if (in_java) {
2487           frame fr;
2488           PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2489           address addr = (address) exceptionRecord->ExceptionInformation[1];
2490           if (os::win32::get_frame_at_stack_banging_point(thread, exceptionInfo, pc, &fr)) {
2491             assert(fr.is_java_frame(), "Must be a Java frame");
2492             SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
2493           }
2494         }
2495         // Yellow zone violation.  The o/s has unprotected the first yellow
2496         // zone page for us.  Note:  must call disable_stack_yellow_zone to
2497         // update the enabled status, even if the zone contains only one page.
2498         assert(thread->thread_state() != _thread_in_vm, "Undersized StackShadowPages");
2499         thread->disable_stack_yellow_reserved_zone();
2500         // If not in java code, return and hope for the best.
2501         return in_java
2502             ? Handle_Exception(exceptionInfo, SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW))
2503             :  EXCEPTION_CONTINUE_EXECUTION;
2504       } else {
2505         // Fatal red zone violation.
2506         thread->disable_stack_red_zone();
2507         tty->print_raw_cr("An unrecoverable stack overflow has occurred.");
2508         report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
2509                       exceptionInfo->ContextRecord);
2510         return EXCEPTION_CONTINUE_SEARCH;
2511       }
2512     } else if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2513       // Either stack overflow or null pointer exception.
2514       if (in_java) {
2515         PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2516         address addr = (address) exceptionRecord->ExceptionInformation[1];
2517         address stack_end = thread->stack_end();
2518         if (addr < stack_end && addr >= stack_end - os::vm_page_size()) {
2519           // Stack overflow.
2520           assert(!os::uses_stack_guard_pages(),
2521                  "should be caught by red zone code above.");
2522           return Handle_Exception(exceptionInfo,
2523                                   SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW));
2524         }
2525         // Check for safepoint polling and implicit null
2526         // We only expect null pointers in the stubs (vtable)
2527         // the rest are checked explicitly now.
2528         CodeBlob* cb = CodeCache::find_blob(pc);
2529         if (cb != NULL) {
2530           if (os::is_poll_address(addr)) {
2531             address stub = SharedRuntime::get_poll_stub(pc);
2532             return Handle_Exception(exceptionInfo, stub);
2533           }
2534         }
2535         {
2536 #ifdef _WIN64
2537           // If it's a legal stack address map the entire region in
2538           //
2539           PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2540           address addr = (address) exceptionRecord->ExceptionInformation[1];
2541           if (addr > thread->stack_reserved_zone_base() && addr < thread->stack_base()) {
2542             addr = (address)((uintptr_t)addr &
2543                              (~((uintptr_t)os::vm_page_size() - (uintptr_t)1)));
2544             os::commit_memory((char *)addr, thread->stack_base() - addr,
2545                               !ExecMem);
2546             return EXCEPTION_CONTINUE_EXECUTION;
2547           } else
2548 #endif
2549           {
2550             // Null pointer exception.
2551             if (MacroAssembler::uses_implicit_null_check((void*)addr)) {
2552               address stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
2553               if (stub != NULL) return Handle_Exception(exceptionInfo, stub);
2554             }
2555             report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
2556                          exceptionInfo->ContextRecord);
2557             return EXCEPTION_CONTINUE_SEARCH;
2558           }
2559         }
2560       }
2561 
2562 #ifdef _WIN64
2563       // Special care for fast JNI field accessors.
2564       // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks
2565       // in and the heap gets shrunk before the field access.
2566       if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2567         address addr = JNI_FastGetField::find_slowcase_pc(pc);
2568         if (addr != (address)-1) {
2569           return Handle_Exception(exceptionInfo, addr);
2570         }
2571       }
2572 #endif
2573 
2574       // Stack overflow or null pointer exception in native code.
2575       report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
2576                    exceptionInfo->ContextRecord);
2577       return EXCEPTION_CONTINUE_SEARCH;
2578     } // /EXCEPTION_ACCESS_VIOLATION
2579     // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
2580 
2581     if (exception_code == EXCEPTION_IN_PAGE_ERROR) {
2582       CompiledMethod* nm = NULL;
2583       JavaThread* thread = (JavaThread*)t;
2584       if (in_java) {
2585         CodeBlob* cb = CodeCache::find_blob_unsafe(pc);
2586         nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL;
2587       }
2588 
2589       bool is_unsafe_arraycopy = (thread->thread_state() == _thread_in_native || in_java) && UnsafeCopyMemory::contains_pc(pc);
2590       if (((thread->thread_state() == _thread_in_vm ||
2591            thread->thread_state() == _thread_in_native ||
2592            is_unsafe_arraycopy) &&
2593           thread->doing_unsafe_access()) ||
2594           (nm != NULL && nm->has_unsafe_access())) {
2595         address next_pc =  Assembler::locate_next_instruction(pc);
2596         if (is_unsafe_arraycopy) {
2597           next_pc = UnsafeCopyMemory::page_error_continue_pc(pc);
2598         }
2599         return Handle_Exception(exceptionInfo, SharedRuntime::handle_unsafe_access(thread, next_pc));
2600       }
2601     }
2602 
2603     if (in_java) {
2604       switch (exception_code) {
2605       case EXCEPTION_INT_DIVIDE_BY_ZERO:
2606         return Handle_Exception(exceptionInfo, SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO));
2607 
2608       case EXCEPTION_INT_OVERFLOW:
2609         return Handle_IDiv_Exception(exceptionInfo);
2610 
2611       } // switch
2612     }
2613     if (((thread->thread_state() == _thread_in_Java) ||
2614          (thread->thread_state() == _thread_in_native)) &&
2615          exception_code != EXCEPTION_UNCAUGHT_CXX_EXCEPTION) {
2616       LONG result=Handle_FLT_Exception(exceptionInfo);
2617       if (result==EXCEPTION_CONTINUE_EXECUTION) return result;
2618     }
2619   }
2620 
2621   if (exception_code != EXCEPTION_BREAKPOINT) {
2622     report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
2623                  exceptionInfo->ContextRecord);
2624   }
2625   return EXCEPTION_CONTINUE_SEARCH;
2626 }
2627 
2628 #ifndef _WIN64
2629 // Special care for fast JNI accessors.
2630 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in and
2631 // the heap gets shrunk before the field access.
2632 // Need to install our own structured exception handler since native code may
2633 // install its own.
2634 LONG WINAPI fastJNIAccessorExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
2635   DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode;
2636   if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2637     address pc = (address) exceptionInfo->ContextRecord->Eip;
2638     address addr = JNI_FastGetField::find_slowcase_pc(pc);
2639     if (addr != (address)-1) {
2640       return Handle_Exception(exceptionInfo, addr);
2641     }
2642   }
2643   return EXCEPTION_CONTINUE_SEARCH;
2644 }
2645 
2646 #define DEFINE_FAST_GETFIELD(Return, Fieldname, Result)                     \
2647   Return JNICALL jni_fast_Get##Result##Field_wrapper(JNIEnv *env,           \
2648                                                      jobject obj,           \
2649                                                      jfieldID fieldID) {    \
2650     __try {                                                                 \
2651       return (*JNI_FastGetField::jni_fast_Get##Result##Field_fp)(env,       \
2652                                                                  obj,       \
2653                                                                  fieldID);  \
2654     } __except(fastJNIAccessorExceptionFilter((_EXCEPTION_POINTERS*)        \
2655                                               _exception_info())) {         \
2656     }                                                                       \
2657     return 0;                                                               \
2658   }
2659 
2660 DEFINE_FAST_GETFIELD(jboolean, bool,   Boolean)
2661 DEFINE_FAST_GETFIELD(jbyte,    byte,   Byte)
2662 DEFINE_FAST_GETFIELD(jchar,    char,   Char)
2663 DEFINE_FAST_GETFIELD(jshort,   short,  Short)
2664 DEFINE_FAST_GETFIELD(jint,     int,    Int)
2665 DEFINE_FAST_GETFIELD(jlong,    long,   Long)
2666 DEFINE_FAST_GETFIELD(jfloat,   float,  Float)
2667 DEFINE_FAST_GETFIELD(jdouble,  double, Double)
2668 
2669 address os::win32::fast_jni_accessor_wrapper(BasicType type) {
2670   switch (type) {
2671   case T_BOOLEAN: return (address)jni_fast_GetBooleanField_wrapper;
2672   case T_BYTE:    return (address)jni_fast_GetByteField_wrapper;
2673   case T_CHAR:    return (address)jni_fast_GetCharField_wrapper;
2674   case T_SHORT:   return (address)jni_fast_GetShortField_wrapper;
2675   case T_INT:     return (address)jni_fast_GetIntField_wrapper;
2676   case T_LONG:    return (address)jni_fast_GetLongField_wrapper;
2677   case T_FLOAT:   return (address)jni_fast_GetFloatField_wrapper;
2678   case T_DOUBLE:  return (address)jni_fast_GetDoubleField_wrapper;
2679   default:        ShouldNotReachHere();
2680   }
2681   return (address)-1;
2682 }
2683 #endif
2684 
2685 // Virtual Memory
2686 
2687 int os::vm_page_size() { return os::win32::vm_page_size(); }
2688 int os::vm_allocation_granularity() {
2689   return os::win32::vm_allocation_granularity();
2690 }
2691 
2692 // Windows large page support is available on Windows 2003. In order to use
2693 // large page memory, the administrator must first assign additional privilege
2694 // to the user:
2695 //   + select Control Panel -> Administrative Tools -> Local Security Policy
2696 //   + select Local Policies -> User Rights Assignment
2697 //   + double click "Lock pages in memory", add users and/or groups
2698 //   + reboot
2699 // Note the above steps are needed for administrator as well, as administrators
2700 // by default do not have the privilege to lock pages in memory.
2701 //
2702 // Note about Windows 2003: although the API supports committing large page
2703 // memory on a page-by-page basis and VirtualAlloc() returns success under this
2704 // scenario, I found through experiment it only uses large page if the entire
2705 // memory region is reserved and committed in a single VirtualAlloc() call.
2706 // This makes Windows large page support more or less like Solaris ISM, in
2707 // that the entire heap must be committed upfront. This probably will change
2708 // in the future, if so the code below needs to be revisited.
2709 
2710 #ifndef MEM_LARGE_PAGES
2711   #define MEM_LARGE_PAGES 0x20000000
2712 #endif
2713 
2714 static HANDLE    _hProcess;
2715 static HANDLE    _hToken;
2716 
2717 // Container for NUMA node list info
2718 class NUMANodeListHolder {
2719  private:
2720   int *_numa_used_node_list;  // allocated below
2721   int _numa_used_node_count;
2722 
2723   void free_node_list() {
2724     FREE_C_HEAP_ARRAY(int, _numa_used_node_list);
2725   }
2726 
2727  public:
2728   NUMANodeListHolder() {
2729     _numa_used_node_count = 0;
2730     _numa_used_node_list = NULL;
2731     // do rest of initialization in build routine (after function pointers are set up)
2732   }
2733 
2734   ~NUMANodeListHolder() {
2735     free_node_list();
2736   }
2737 
2738   bool build() {
2739     DWORD_PTR proc_aff_mask;
2740     DWORD_PTR sys_aff_mask;
2741     if (!GetProcessAffinityMask(GetCurrentProcess(), &proc_aff_mask, &sys_aff_mask)) return false;
2742     ULONG highest_node_number;
2743     if (!GetNumaHighestNodeNumber(&highest_node_number)) return false;
2744     free_node_list();
2745     _numa_used_node_list = NEW_C_HEAP_ARRAY(int, highest_node_number + 1, mtInternal);
2746     for (unsigned int i = 0; i <= highest_node_number; i++) {
2747       ULONGLONG proc_mask_numa_node;
2748       if (!GetNumaNodeProcessorMask(i, &proc_mask_numa_node)) return false;
2749       if ((proc_aff_mask & proc_mask_numa_node)!=0) {
2750         _numa_used_node_list[_numa_used_node_count++] = i;
2751       }
2752     }
2753     return (_numa_used_node_count > 1);
2754   }
2755 
2756   int get_count() { return _numa_used_node_count; }
2757   int get_node_list_entry(int n) {
2758     // for indexes out of range, returns -1
2759     return (n < _numa_used_node_count ? _numa_used_node_list[n] : -1);
2760   }
2761 
2762 } numa_node_list_holder;
2763 
2764 
2765 
2766 static size_t _large_page_size = 0;
2767 
2768 static bool request_lock_memory_privilege() {
2769   _hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE,
2770                           os::current_process_id());
2771 
2772   LUID luid;
2773   if (_hProcess != NULL &&
2774       OpenProcessToken(_hProcess, TOKEN_ADJUST_PRIVILEGES, &_hToken) &&
2775       LookupPrivilegeValue(NULL, "SeLockMemoryPrivilege", &luid)) {
2776 
2777     TOKEN_PRIVILEGES tp;
2778     tp.PrivilegeCount = 1;
2779     tp.Privileges[0].Luid = luid;
2780     tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
2781 
2782     // AdjustTokenPrivileges() may return TRUE even when it couldn't change the
2783     // privilege. Check GetLastError() too. See MSDN document.
2784     if (AdjustTokenPrivileges(_hToken, false, &tp, sizeof(tp), NULL, NULL) &&
2785         (GetLastError() == ERROR_SUCCESS)) {
2786       return true;
2787     }
2788   }
2789 
2790   return false;
2791 }
2792 
2793 static void cleanup_after_large_page_init() {
2794   if (_hProcess) CloseHandle(_hProcess);
2795   _hProcess = NULL;
2796   if (_hToken) CloseHandle(_hToken);
2797   _hToken = NULL;
2798 }
2799 
2800 static bool numa_interleaving_init() {
2801   bool success = false;
2802   bool use_numa_interleaving_specified = !FLAG_IS_DEFAULT(UseNUMAInterleaving);
2803 
2804   // print a warning if UseNUMAInterleaving flag is specified on command line
2805   bool warn_on_failure = use_numa_interleaving_specified;
2806 #define WARN(msg) if (warn_on_failure) { warning(msg); }
2807 
2808   // NUMAInterleaveGranularity cannot be less than vm_allocation_granularity (or _large_page_size if using large pages)
2809   size_t min_interleave_granularity = UseLargePages ? _large_page_size : os::vm_allocation_granularity();
2810   NUMAInterleaveGranularity = align_up(NUMAInterleaveGranularity, min_interleave_granularity);
2811 
2812   if (numa_node_list_holder.build()) {
2813     if (log_is_enabled(Debug, os, cpu)) {
2814       Log(os, cpu) log;
2815       log.debug("NUMA UsedNodeCount=%d, namely ", numa_node_list_holder.get_count());
2816       for (int i = 0; i < numa_node_list_holder.get_count(); i++) {
2817         log.debug("  %d ", numa_node_list_holder.get_node_list_entry(i));
2818       }
2819     }
2820     success = true;
2821   } else {
2822     WARN("Process does not cover multiple NUMA nodes.");
2823   }
2824   if (!success) {
2825     if (use_numa_interleaving_specified) WARN("...Ignoring UseNUMAInterleaving flag.");
2826   }
2827   return success;
2828 #undef WARN
2829 }
2830 
2831 // this routine is used whenever we need to reserve a contiguous VA range
2832 // but we need to make separate VirtualAlloc calls for each piece of the range
2833 // Reasons for doing this:
2834 //  * UseLargePagesIndividualAllocation was set (normally only needed on WS2003 but possible to be set otherwise)
2835 //  * UseNUMAInterleaving requires a separate node for each piece
2836 static char* allocate_pages_individually(size_t bytes, char* addr, DWORD flags,
2837                                          DWORD prot,
2838                                          bool should_inject_error = false) {
2839   char * p_buf;
2840   // note: at setup time we guaranteed that NUMAInterleaveGranularity was aligned up to a page size
2841   size_t page_size = UseLargePages ? _large_page_size : os::vm_allocation_granularity();
2842   size_t chunk_size = UseNUMAInterleaving ? NUMAInterleaveGranularity : page_size;
2843 
2844   // first reserve enough address space in advance since we want to be
2845   // able to break a single contiguous virtual address range into multiple
2846   // large page commits but WS2003 does not allow reserving large page space
2847   // so we just use 4K pages for reserve, this gives us a legal contiguous
2848   // address space. then we will deallocate that reservation, and re alloc
2849   // using large pages
2850   const size_t size_of_reserve = bytes + chunk_size;
2851   if (bytes > size_of_reserve) {
2852     // Overflowed.
2853     return NULL;
2854   }
2855   p_buf = (char *) VirtualAlloc(addr,
2856                                 size_of_reserve,  // size of Reserve
2857                                 MEM_RESERVE,
2858                                 PAGE_READWRITE);
2859   // If reservation failed, return NULL
2860   if (p_buf == NULL) return NULL;
2861   MemTracker::record_virtual_memory_reserve((address)p_buf, size_of_reserve, CALLER_PC);
2862   os::release_memory(p_buf, bytes + chunk_size);
2863 
2864   // we still need to round up to a page boundary (in case we are using large pages)
2865   // but not to a chunk boundary (in case InterleavingGranularity doesn't align with page size)
2866   // instead we handle this in the bytes_to_rq computation below
2867   p_buf = align_up(p_buf, page_size);
2868 
2869   // now go through and allocate one chunk at a time until all bytes are
2870   // allocated
2871   size_t  bytes_remaining = bytes;
2872   // An overflow of align_up() would have been caught above
2873   // in the calculation of size_of_reserve.
2874   char * next_alloc_addr = p_buf;
2875   HANDLE hProc = GetCurrentProcess();
2876 
2877 #ifdef ASSERT
2878   // Variable for the failure injection
2879   int ran_num = os::random();
2880   size_t fail_after = ran_num % bytes;
2881 #endif
2882 
2883   int count=0;
2884   while (bytes_remaining) {
2885     // select bytes_to_rq to get to the next chunk_size boundary
2886 
2887     size_t bytes_to_rq = MIN2(bytes_remaining, chunk_size - ((size_t)next_alloc_addr % chunk_size));
2888     // Note allocate and commit
2889     char * p_new;
2890 
2891 #ifdef ASSERT
2892     bool inject_error_now = should_inject_error && (bytes_remaining <= fail_after);
2893 #else
2894     const bool inject_error_now = false;
2895 #endif
2896 
2897     if (inject_error_now) {
2898       p_new = NULL;
2899     } else {
2900       if (!UseNUMAInterleaving) {
2901         p_new = (char *) VirtualAlloc(next_alloc_addr,
2902                                       bytes_to_rq,
2903                                       flags,
2904                                       prot);
2905       } else {
2906         // get the next node to use from the used_node_list
2907         assert(numa_node_list_holder.get_count() > 0, "Multiple NUMA nodes expected");
2908         DWORD node = numa_node_list_holder.get_node_list_entry(count % numa_node_list_holder.get_count());
2909         p_new = (char *)VirtualAllocExNuma(hProc, next_alloc_addr, bytes_to_rq, flags, prot, node);
2910       }
2911     }
2912 
2913     if (p_new == NULL) {
2914       // Free any allocated pages
2915       if (next_alloc_addr > p_buf) {
2916         // Some memory was committed so release it.
2917         size_t bytes_to_release = bytes - bytes_remaining;
2918         // NMT has yet to record any individual blocks, so it
2919         // need to create a dummy 'reserve' record to match
2920         // the release.
2921         MemTracker::record_virtual_memory_reserve((address)p_buf,
2922                                                   bytes_to_release, CALLER_PC);
2923         os::release_memory(p_buf, bytes_to_release);
2924       }
2925 #ifdef ASSERT
2926       if (should_inject_error) {
2927         log_develop_debug(pagesize)("Reserving pages individually failed.");
2928       }
2929 #endif
2930       return NULL;
2931     }
2932 
2933     bytes_remaining -= bytes_to_rq;
2934     next_alloc_addr += bytes_to_rq;
2935     count++;
2936   }
2937   // Although the memory is allocated individually, it is returned as one.
2938   // NMT records it as one block.
2939   if ((flags & MEM_COMMIT) != 0) {
2940     MemTracker::record_virtual_memory_reserve_and_commit((address)p_buf, bytes, CALLER_PC);
2941   } else {
2942     MemTracker::record_virtual_memory_reserve((address)p_buf, bytes, CALLER_PC);
2943   }
2944 
2945   // made it this far, success
2946   return p_buf;
2947 }
2948 
2949 
2950 
2951 void os::large_page_init() {
2952   if (!UseLargePages) return;
2953 
2954   // print a warning if any large page related flag is specified on command line
2955   bool warn_on_failure = !FLAG_IS_DEFAULT(UseLargePages) ||
2956                          !FLAG_IS_DEFAULT(LargePageSizeInBytes);
2957   bool success = false;
2958 
2959 #define WARN(msg) if (warn_on_failure) { warning(msg); }
2960   if (request_lock_memory_privilege()) {
2961     size_t s = GetLargePageMinimum();
2962     if (s) {
2963 #if defined(IA32) || defined(AMD64)
2964       if (s > 4*M || LargePageSizeInBytes > 4*M) {
2965         WARN("JVM cannot use large pages bigger than 4mb.");
2966       } else {
2967 #endif
2968         if (LargePageSizeInBytes && LargePageSizeInBytes % s == 0) {
2969           _large_page_size = LargePageSizeInBytes;
2970         } else {
2971           _large_page_size = s;
2972         }
2973         success = true;
2974 #if defined(IA32) || defined(AMD64)
2975       }
2976 #endif
2977     } else {
2978       WARN("Large page is not supported by the processor.");
2979     }
2980   } else {
2981     WARN("JVM cannot use large page memory because it does not have enough privilege to lock pages in memory.");
2982   }
2983 #undef WARN
2984 
2985   const size_t default_page_size = (size_t) vm_page_size();
2986   if (success && _large_page_size > default_page_size) {
2987     _page_sizes[0] = _large_page_size;
2988     _page_sizes[1] = default_page_size;
2989     _page_sizes[2] = 0;
2990   }
2991 
2992   cleanup_after_large_page_init();
2993   UseLargePages = success;
2994 }
2995 
2996 int os::create_file_for_heap(const char* dir) {
2997 
2998   const char name_template[] = "/jvmheap.XXXXXX";
2999 
3000   size_t fullname_len = strlen(dir) + strlen(name_template);
3001   char *fullname = (char*)os::malloc(fullname_len + 1, mtInternal);
3002   if (fullname == NULL) {
3003     vm_exit_during_initialization(err_msg("Malloc failed during creation of backing file for heap (%s)", os::strerror(errno)));
3004     return -1;
3005   }
3006   int n = snprintf(fullname, fullname_len + 1, "%s%s", dir, name_template);
3007   assert((size_t)n == fullname_len, "Unexpected number of characters in string");
3008 
3009   os::native_path(fullname);
3010 
3011   char *path = _mktemp(fullname);
3012   if (path == NULL) {
3013     warning("_mktemp could not create file name from template %s (%s)", fullname, os::strerror(errno));
3014     os::free(fullname);
3015     return -1;
3016   }
3017 
3018   int fd = _open(path, O_RDWR | O_CREAT | O_TEMPORARY | O_EXCL, S_IWRITE | S_IREAD);
3019 
3020   os::free(fullname);
3021   if (fd < 0) {
3022     warning("Problem opening file for heap (%s)", os::strerror(errno));
3023     return -1;
3024   }
3025   return fd;
3026 }
3027 
3028 // If 'base' is not NULL, function will return NULL if it cannot get 'base'
3029 char* os::map_memory_to_file(char* base, size_t size, int fd) {
3030   assert(fd != -1, "File descriptor is not valid");
3031 
3032   HANDLE fh = (HANDLE)_get_osfhandle(fd);
3033 #ifdef _LP64
3034   HANDLE fileMapping = CreateFileMapping(fh, NULL, PAGE_READWRITE,
3035     (DWORD)(size >> 32), (DWORD)(size & 0xFFFFFFFF), NULL);
3036 #else
3037   HANDLE fileMapping = CreateFileMapping(fh, NULL, PAGE_READWRITE,
3038     0, (DWORD)size, NULL);
3039 #endif
3040   if (fileMapping == NULL) {
3041     if (GetLastError() == ERROR_DISK_FULL) {
3042       vm_exit_during_initialization(err_msg("Could not allocate sufficient disk space for Java heap"));
3043     }
3044     else {
3045       vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
3046     }
3047 
3048     return NULL;
3049   }
3050 
3051   LPVOID addr = MapViewOfFileEx(fileMapping, FILE_MAP_WRITE, 0, 0, size, base);
3052 
3053   CloseHandle(fileMapping);
3054 
3055   return (char*)addr;
3056 }
3057 
3058 char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
3059   assert(fd != -1, "File descriptor is not valid");
3060   assert(base != NULL, "Base address cannot be NULL");
3061 
3062   release_memory(base, size);
3063   return map_memory_to_file(base, size, fd);
3064 }
3065 
3066 // On win32, one cannot release just a part of reserved memory, it's an
3067 // all or nothing deal.  When we split a reservation, we must break the
3068 // reservation into two reservations.
3069 void os::pd_split_reserved_memory(char *base, size_t size, size_t split,
3070                                   bool realloc) {
3071   if (size > 0) {
3072     release_memory(base, size);
3073     if (realloc) {
3074       reserve_memory(split, base);
3075     }
3076     if (size != split) {
3077       reserve_memory(size - split, base + split);
3078     }
3079   }
3080 }
3081 
3082 // Multiple threads can race in this code but it's not possible to unmap small sections of
3083 // virtual space to get requested alignment, like posix-like os's.
3084 // Windows prevents multiple thread from remapping over each other so this loop is thread-safe.
3085 char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
3086   assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
3087          "Alignment must be a multiple of allocation granularity (page size)");
3088   assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
3089 
3090   size_t extra_size = size + alignment;
3091   assert(extra_size >= size, "overflow, size is too large to allow alignment");
3092 
3093   char* aligned_base = NULL;
3094 
3095   do {
3096     char* extra_base = os::reserve_memory(extra_size, NULL, alignment, file_desc);
3097     if (extra_base == NULL) {
3098       return NULL;
3099     }
3100     // Do manual alignment
3101     aligned_base = align_up(extra_base, alignment);
3102 
3103     if (file_desc != -1) {
3104       os::unmap_memory(extra_base, extra_size);
3105     } else {
3106       os::release_memory(extra_base, extra_size);
3107     }
3108 
3109     aligned_base = os::reserve_memory(size, aligned_base, 0, file_desc);
3110 
3111   } while (aligned_base == NULL);
3112 
3113   return aligned_base;
3114 }
3115 
3116 char* os::pd_reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
3117   assert((size_t)addr % os::vm_allocation_granularity() == 0,
3118          "reserve alignment");
3119   assert(bytes % os::vm_page_size() == 0, "reserve page size");
3120   char* res;
3121   // note that if UseLargePages is on, all the areas that require interleaving
3122   // will go thru reserve_memory_special rather than thru here.
3123   bool use_individual = (UseNUMAInterleaving && !UseLargePages);
3124   if (!use_individual) {
3125     res = (char*)VirtualAlloc(addr, bytes, MEM_RESERVE, PAGE_READWRITE);
3126   } else {
3127     elapsedTimer reserveTimer;
3128     if (Verbose && PrintMiscellaneous) reserveTimer.start();
3129     // in numa interleaving, we have to allocate pages individually
3130     // (well really chunks of NUMAInterleaveGranularity size)
3131     res = allocate_pages_individually(bytes, addr, MEM_RESERVE, PAGE_READWRITE);
3132     if (res == NULL) {
3133       warning("NUMA page allocation failed");
3134     }
3135     if (Verbose && PrintMiscellaneous) {
3136       reserveTimer.stop();
3137       tty->print_cr("reserve_memory of %Ix bytes took " JLONG_FORMAT " ms (" JLONG_FORMAT " ticks)", bytes,
3138                     reserveTimer.milliseconds(), reserveTimer.ticks());
3139     }
3140   }
3141   assert(res == NULL || addr == NULL || addr == res,
3142          "Unexpected address from reserve.");
3143 
3144   return res;
3145 }
3146 
3147 // Reserve memory at an arbitrary address, only if that area is
3148 // available (and not reserved for something else).
3149 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
3150   // Windows os::reserve_memory() fails of the requested address range is
3151   // not avilable.
3152   return reserve_memory(bytes, requested_addr);
3153 }
3154 
3155 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
3156   assert(file_desc >= 0, "file_desc is not valid");
3157   return map_memory_to_file(requested_addr, bytes, file_desc);
3158 }
3159 
3160 size_t os::large_page_size() {
3161   return _large_page_size;
3162 }
3163 
3164 bool os::can_commit_large_page_memory() {
3165   // Windows only uses large page memory when the entire region is reserved
3166   // and committed in a single VirtualAlloc() call. This may change in the
3167   // future, but with Windows 2003 it's not possible to commit on demand.
3168   return false;
3169 }
3170 
3171 bool os::can_execute_large_page_memory() {
3172   return true;
3173 }
3174 
3175 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* addr,
3176                                  bool exec) {
3177   assert(UseLargePages, "only for large pages");
3178 
3179   if (!is_aligned(bytes, os::large_page_size()) || alignment > os::large_page_size()) {
3180     return NULL; // Fallback to small pages.
3181   }
3182 
3183   const DWORD prot = exec ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
3184   const DWORD flags = MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES;
3185 
3186   // with large pages, there are two cases where we need to use Individual Allocation
3187   // 1) the UseLargePagesIndividualAllocation flag is set (set by default on WS2003)
3188   // 2) NUMA Interleaving is enabled, in which case we use a different node for each page
3189   if (UseLargePagesIndividualAllocation || UseNUMAInterleaving) {
3190     log_debug(pagesize)("Reserving large pages individually.");
3191 
3192     char * p_buf = allocate_pages_individually(bytes, addr, flags, prot, LargePagesIndividualAllocationInjectError);
3193     if (p_buf == NULL) {
3194       // give an appropriate warning message
3195       if (UseNUMAInterleaving) {
3196         warning("NUMA large page allocation failed, UseLargePages flag ignored");
3197       }
3198       if (UseLargePagesIndividualAllocation) {
3199         warning("Individually allocated large pages failed, "
3200                 "use -XX:-UseLargePagesIndividualAllocation to turn off");
3201       }
3202       return NULL;
3203     }
3204 
3205     return p_buf;
3206 
3207   } else {
3208     log_debug(pagesize)("Reserving large pages in a single large chunk.");
3209 
3210     // normal policy just allocate it all at once
3211     DWORD flag = MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES;
3212     char * res = (char *)VirtualAlloc(addr, bytes, flag, prot);
3213     if (res != NULL) {
3214       MemTracker::record_virtual_memory_reserve_and_commit((address)res, bytes, CALLER_PC);
3215     }
3216 
3217     return res;
3218   }
3219 }
3220 
3221 bool os::release_memory_special(char* base, size_t bytes) {
3222   assert(base != NULL, "Sanity check");
3223   return release_memory(base, bytes);
3224 }
3225 
3226 void os::print_statistics() {
3227 }
3228 
3229 static void warn_fail_commit_memory(char* addr, size_t bytes, bool exec) {
3230   int err = os::get_last_error();
3231   char buf[256];
3232   size_t buf_len = os::lasterror(buf, sizeof(buf));
3233   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
3234           ", %d) failed; error='%s' (DOS error/errno=%d)", addr, bytes,
3235           exec, buf_len != 0 ? buf : "<no_error_string>", err);
3236 }
3237 
3238 bool os::pd_commit_memory(char* addr, size_t bytes, bool exec) {
3239   if (bytes == 0) {
3240     // Don't bother the OS with noops.
3241     return true;
3242   }
3243   assert((size_t) addr % os::vm_page_size() == 0, "commit on page boundaries");
3244   assert(bytes % os::vm_page_size() == 0, "commit in page-sized chunks");
3245   // Don't attempt to print anything if the OS call fails. We're
3246   // probably low on resources, so the print itself may cause crashes.
3247 
3248   // unless we have NUMAInterleaving enabled, the range of a commit
3249   // is always within a reserve covered by a single VirtualAlloc
3250   // in that case we can just do a single commit for the requested size
3251   if (!UseNUMAInterleaving) {
3252     if (VirtualAlloc(addr, bytes, MEM_COMMIT, PAGE_READWRITE) == NULL) {
3253       NOT_PRODUCT(warn_fail_commit_memory(addr, bytes, exec);)
3254       return false;
3255     }
3256     if (exec) {
3257       DWORD oldprot;
3258       // Windows doc says to use VirtualProtect to get execute permissions
3259       if (!VirtualProtect(addr, bytes, PAGE_EXECUTE_READWRITE, &oldprot)) {
3260         NOT_PRODUCT(warn_fail_commit_memory(addr, bytes, exec);)
3261         return false;
3262       }
3263     }
3264     return true;
3265   } else {
3266 
3267     // when NUMAInterleaving is enabled, the commit might cover a range that
3268     // came from multiple VirtualAlloc reserves (using allocate_pages_individually).
3269     // VirtualQuery can help us determine that.  The RegionSize that VirtualQuery
3270     // returns represents the number of bytes that can be committed in one step.
3271     size_t bytes_remaining = bytes;
3272     char * next_alloc_addr = addr;
3273     while (bytes_remaining > 0) {
3274       MEMORY_BASIC_INFORMATION alloc_info;
3275       VirtualQuery(next_alloc_addr, &alloc_info, sizeof(alloc_info));
3276       size_t bytes_to_rq = MIN2(bytes_remaining, (size_t)alloc_info.RegionSize);
3277       if (VirtualAlloc(next_alloc_addr, bytes_to_rq, MEM_COMMIT,
3278                        PAGE_READWRITE) == NULL) {
3279         NOT_PRODUCT(warn_fail_commit_memory(next_alloc_addr, bytes_to_rq,
3280                                             exec);)
3281         return false;
3282       }
3283       if (exec) {
3284         DWORD oldprot;
3285         if (!VirtualProtect(next_alloc_addr, bytes_to_rq,
3286                             PAGE_EXECUTE_READWRITE, &oldprot)) {
3287           NOT_PRODUCT(warn_fail_commit_memory(next_alloc_addr, bytes_to_rq,
3288                                               exec);)
3289           return false;
3290         }
3291       }
3292       bytes_remaining -= bytes_to_rq;
3293       next_alloc_addr += bytes_to_rq;
3294     }
3295   }
3296   // if we made it this far, return true
3297   return true;
3298 }
3299 
3300 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
3301                           bool exec) {
3302   // alignment_hint is ignored on this OS
3303   return pd_commit_memory(addr, size, exec);
3304 }
3305 
3306 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
3307                                   const char* mesg) {
3308   assert(mesg != NULL, "mesg must be specified");
3309   if (!pd_commit_memory(addr, size, exec)) {
3310     warn_fail_commit_memory(addr, size, exec);
3311     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
3312   }
3313 }
3314 
3315 void os::pd_commit_memory_or_exit(char* addr, size_t size,
3316                                   size_t alignment_hint, bool exec,
3317                                   const char* mesg) {
3318   // alignment_hint is ignored on this OS
3319   pd_commit_memory_or_exit(addr, size, exec, mesg);
3320 }
3321 
3322 bool os::pd_uncommit_memory(char* addr, size_t bytes) {
3323   if (bytes == 0) {
3324     // Don't bother the OS with noops.
3325     return true;
3326   }
3327   assert((size_t) addr % os::vm_page_size() == 0, "uncommit on page boundaries");
3328   assert(bytes % os::vm_page_size() == 0, "uncommit in page-sized chunks");
3329   return (VirtualFree(addr, bytes, MEM_DECOMMIT) != 0);
3330 }
3331 
3332 bool os::pd_release_memory(char* addr, size_t bytes) {
3333   return VirtualFree(addr, 0, MEM_RELEASE) != 0;
3334 }
3335 
3336 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
3337   return os::commit_memory(addr, size, !ExecMem);
3338 }
3339 
3340 bool os::remove_stack_guard_pages(char* addr, size_t size) {
3341   return os::uncommit_memory(addr, size);
3342 }
3343 
3344 static bool protect_pages_individually(char* addr, size_t bytes, unsigned int p, DWORD *old_status) {
3345   uint count = 0;
3346   bool ret = false;
3347   size_t bytes_remaining = bytes;
3348   char * next_protect_addr = addr;
3349 
3350   // Use VirtualQuery() to get the chunk size.
3351   while (bytes_remaining) {
3352     MEMORY_BASIC_INFORMATION alloc_info;
3353     if (VirtualQuery(next_protect_addr, &alloc_info, sizeof(alloc_info)) == 0) {
3354       return false;
3355     }
3356 
3357     size_t bytes_to_protect = MIN2(bytes_remaining, (size_t)alloc_info.RegionSize);
3358     // We used different API at allocate_pages_individually() based on UseNUMAInterleaving,
3359     // but we don't distinguish here as both cases are protected by same API.
3360     ret = VirtualProtect(next_protect_addr, bytes_to_protect, p, old_status) != 0;
3361     warning("Failed protecting pages individually for chunk #%u", count);
3362     if (!ret) {
3363       return false;
3364     }
3365 
3366     bytes_remaining -= bytes_to_protect;
3367     next_protect_addr += bytes_to_protect;
3368     count++;
3369   }
3370   return ret;
3371 }
3372 
3373 // Set protections specified
3374 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
3375                         bool is_committed) {
3376   unsigned int p = 0;
3377   switch (prot) {
3378   case MEM_PROT_NONE: p = PAGE_NOACCESS; break;
3379   case MEM_PROT_READ: p = PAGE_READONLY; break;
3380   case MEM_PROT_RW:   p = PAGE_READWRITE; break;
3381   case MEM_PROT_RWX:  p = PAGE_EXECUTE_READWRITE; break;
3382   default:
3383     ShouldNotReachHere();
3384   }
3385 
3386   DWORD old_status;
3387 
3388   // Strange enough, but on Win32 one can change protection only for committed
3389   // memory, not a big deal anyway, as bytes less or equal than 64K
3390   if (!is_committed) {
3391     commit_memory_or_exit(addr, bytes, prot == MEM_PROT_RWX,
3392                           "cannot commit protection page");
3393   }
3394   // One cannot use os::guard_memory() here, as on Win32 guard page
3395   // have different (one-shot) semantics, from MSDN on PAGE_GUARD:
3396   //
3397   // Pages in the region become guard pages. Any attempt to access a guard page
3398   // causes the system to raise a STATUS_GUARD_PAGE exception and turn off
3399   // the guard page status. Guard pages thus act as a one-time access alarm.
3400   bool ret;
3401   if (UseNUMAInterleaving) {
3402     // If UseNUMAInterleaving is enabled, the pages may have been allocated a chunk at a time,
3403     // so we must protect the chunks individually.
3404     ret = protect_pages_individually(addr, bytes, p, &old_status);
3405   } else {
3406     ret = VirtualProtect(addr, bytes, p, &old_status) != 0;
3407   }
3408 #ifdef ASSERT
3409   if (!ret) {
3410     int err = os::get_last_error();
3411     char buf[256];
3412     size_t buf_len = os::lasterror(buf, sizeof(buf));
3413     warning("INFO: os::protect_memory(" PTR_FORMAT ", " SIZE_FORMAT
3414           ") failed; error='%s' (DOS error/errno=%d)", addr, bytes,
3415           buf_len != 0 ? buf : "<no_error_string>", err);
3416   }
3417 #endif
3418   return ret;
3419 }
3420 
3421 bool os::guard_memory(char* addr, size_t bytes) {
3422   DWORD old_status;
3423   return VirtualProtect(addr, bytes, PAGE_READWRITE | PAGE_GUARD, &old_status) != 0;
3424 }
3425 
3426 bool os::unguard_memory(char* addr, size_t bytes) {
3427   DWORD old_status;
3428   return VirtualProtect(addr, bytes, PAGE_READWRITE, &old_status) != 0;
3429 }
3430 
3431 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { }
3432 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { }
3433 void os::numa_make_global(char *addr, size_t bytes)    { }
3434 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint)    { }
3435 bool os::numa_topology_changed()                       { return false; }
3436 size_t os::numa_get_groups_num()                       { return MAX2(numa_node_list_holder.get_count(), 1); }
3437 int os::numa_get_group_id()                            { return 0; }
3438 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
3439   if (numa_node_list_holder.get_count() == 0 && size > 0) {
3440     // Provide an answer for UMA systems
3441     ids[0] = 0;
3442     return 1;
3443   } else {
3444     // check for size bigger than actual groups_num
3445     size = MIN2(size, numa_get_groups_num());
3446     for (int i = 0; i < (int)size; i++) {
3447       ids[i] = numa_node_list_holder.get_node_list_entry(i);
3448     }
3449     return size;
3450   }
3451 }
3452 
3453 bool os::get_page_info(char *start, page_info* info) {
3454   return false;
3455 }
3456 
3457 char *os::scan_pages(char *start, char* end, page_info* page_expected,
3458                      page_info* page_found) {
3459   return end;
3460 }
3461 
3462 char* os::non_memory_address_word() {
3463   // Must never look like an address returned by reserve_memory,
3464   // even in its subfields (as defined by the CPU immediate fields,
3465   // if the CPU splits constants across multiple instructions).
3466   return (char*)-1;
3467 }
3468 
3469 #define MAX_ERROR_COUNT 100
3470 #define SYS_THREAD_ERROR 0xffffffffUL
3471 
3472 void os::pd_start_thread(Thread* thread) {
3473   DWORD ret = ResumeThread(thread->osthread()->thread_handle());
3474   // Returns previous suspend state:
3475   // 0:  Thread was not suspended
3476   // 1:  Thread is running now
3477   // >1: Thread is still suspended.
3478   assert(ret != SYS_THREAD_ERROR, "StartThread failed"); // should propagate back
3479 }
3480 
3481 
3482 // Short sleep, direct OS call.
3483 //
3484 // ms = 0, means allow others (if any) to run.
3485 //
3486 void os::naked_short_sleep(jlong ms) {
3487   assert(ms < 1000, "Un-interruptable sleep, short time use only");
3488   Sleep(ms);
3489 }
3490 
3491 // Windows does not provide sleep functionality with nanosecond resolution, so we
3492 // try to approximate this with spinning combined with yielding if another thread
3493 // is ready to run on the current processor.
3494 void os::naked_short_nanosleep(jlong ns) {
3495   assert(ns > -1 && ns < NANOUNITS, "Un-interruptable sleep, short time use only");
3496 
3497   int64_t start = os::javaTimeNanos();
3498   do {
3499     if (SwitchToThread() == 0) {
3500       // Nothing else is ready to run on this cpu, spin a little
3501       SpinPause();
3502     }
3503   } while (os::javaTimeNanos() - start < ns);
3504 }
3505 
3506 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
3507 void os::infinite_sleep() {
3508   while (true) {    // sleep forever ...
3509     Sleep(100000);  // ... 100 seconds at a time
3510   }
3511 }
3512 
3513 typedef BOOL (WINAPI * STTSignature)(void);
3514 
3515 void os::naked_yield() {
3516   // Consider passing back the return value from SwitchToThread().
3517   SwitchToThread();
3518 }
3519 
3520 // Win32 only gives you access to seven real priorities at a time,
3521 // so we compress Java's ten down to seven.  It would be better
3522 // if we dynamically adjusted relative priorities.
3523 
3524 int os::java_to_os_priority[CriticalPriority + 1] = {
3525   THREAD_PRIORITY_IDLE,                         // 0  Entry should never be used
3526   THREAD_PRIORITY_LOWEST,                       // 1  MinPriority
3527   THREAD_PRIORITY_LOWEST,                       // 2
3528   THREAD_PRIORITY_BELOW_NORMAL,                 // 3
3529   THREAD_PRIORITY_BELOW_NORMAL,                 // 4
3530   THREAD_PRIORITY_NORMAL,                       // 5  NormPriority
3531   THREAD_PRIORITY_NORMAL,                       // 6
3532   THREAD_PRIORITY_ABOVE_NORMAL,                 // 7
3533   THREAD_PRIORITY_ABOVE_NORMAL,                 // 8
3534   THREAD_PRIORITY_HIGHEST,                      // 9  NearMaxPriority
3535   THREAD_PRIORITY_HIGHEST,                      // 10 MaxPriority
3536   THREAD_PRIORITY_HIGHEST                       // 11 CriticalPriority
3537 };
3538 
3539 int prio_policy1[CriticalPriority + 1] = {
3540   THREAD_PRIORITY_IDLE,                         // 0  Entry should never be used
3541   THREAD_PRIORITY_LOWEST,                       // 1  MinPriority
3542   THREAD_PRIORITY_LOWEST,                       // 2
3543   THREAD_PRIORITY_BELOW_NORMAL,                 // 3
3544   THREAD_PRIORITY_BELOW_NORMAL,                 // 4
3545   THREAD_PRIORITY_NORMAL,                       // 5  NormPriority
3546   THREAD_PRIORITY_ABOVE_NORMAL,                 // 6
3547   THREAD_PRIORITY_ABOVE_NORMAL,                 // 7
3548   THREAD_PRIORITY_HIGHEST,                      // 8
3549   THREAD_PRIORITY_HIGHEST,                      // 9  NearMaxPriority
3550   THREAD_PRIORITY_TIME_CRITICAL,                // 10 MaxPriority
3551   THREAD_PRIORITY_TIME_CRITICAL                 // 11 CriticalPriority
3552 };
3553 
3554 static int prio_init() {
3555   // If ThreadPriorityPolicy is 1, switch tables
3556   if (ThreadPriorityPolicy == 1) {
3557     int i;
3558     for (i = 0; i < CriticalPriority + 1; i++) {
3559       os::java_to_os_priority[i] = prio_policy1[i];
3560     }
3561   }
3562   if (UseCriticalJavaThreadPriority) {
3563     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
3564   }
3565   return 0;
3566 }
3567 
3568 OSReturn os::set_native_priority(Thread* thread, int priority) {
3569   if (!UseThreadPriorities) return OS_OK;
3570   bool ret = SetThreadPriority(thread->osthread()->thread_handle(), priority) != 0;
3571   return ret ? OS_OK : OS_ERR;
3572 }
3573 
3574 OSReturn os::get_native_priority(const Thread* const thread,
3575                                  int* priority_ptr) {
3576   if (!UseThreadPriorities) {
3577     *priority_ptr = java_to_os_priority[NormPriority];
3578     return OS_OK;
3579   }
3580   int os_prio = GetThreadPriority(thread->osthread()->thread_handle());
3581   if (os_prio == THREAD_PRIORITY_ERROR_RETURN) {
3582     assert(false, "GetThreadPriority failed");
3583     return OS_ERR;
3584   }
3585   *priority_ptr = os_prio;
3586   return OS_OK;
3587 }
3588 
3589 // GetCurrentThreadId() returns DWORD
3590 intx os::current_thread_id()  { return GetCurrentThreadId(); }
3591 
3592 static int _initial_pid = 0;
3593 
3594 int os::current_process_id() {
3595   return (_initial_pid ? _initial_pid : _getpid());
3596 }
3597 
3598 int    os::win32::_vm_page_size              = 0;
3599 int    os::win32::_vm_allocation_granularity = 0;
3600 int    os::win32::_processor_type            = 0;
3601 // Processor level is not available on non-NT systems, use vm_version instead
3602 int    os::win32::_processor_level           = 0;
3603 julong os::win32::_physical_memory           = 0;
3604 size_t os::win32::_default_stack_size        = 0;
3605 
3606 intx          os::win32::_os_thread_limit    = 0;
3607 volatile intx os::win32::_os_thread_count    = 0;
3608 
3609 bool   os::win32::_is_windows_server         = false;
3610 
3611 // 6573254
3612 // Currently, the bug is observed across all the supported Windows releases,
3613 // including the latest one (as of this writing - Windows Server 2012 R2)
3614 bool   os::win32::_has_exit_bug              = true;
3615 
3616 void os::win32::initialize_system_info() {
3617   SYSTEM_INFO si;
3618   GetSystemInfo(&si);
3619   _vm_page_size    = si.dwPageSize;
3620   _vm_allocation_granularity = si.dwAllocationGranularity;
3621   _processor_type  = si.dwProcessorType;
3622   _processor_level = si.wProcessorLevel;
3623   set_processor_count(si.dwNumberOfProcessors);
3624 
3625   MEMORYSTATUSEX ms;
3626   ms.dwLength = sizeof(ms);
3627 
3628   // also returns dwAvailPhys (free physical memory bytes), dwTotalVirtual, dwAvailVirtual,
3629   // dwMemoryLoad (% of memory in use)
3630   GlobalMemoryStatusEx(&ms);
3631   _physical_memory = ms.ullTotalPhys;
3632 
3633   if (FLAG_IS_DEFAULT(MaxRAM)) {
3634     // Adjust MaxRAM according to the maximum virtual address space available.
3635     FLAG_SET_DEFAULT(MaxRAM, MIN2(MaxRAM, (uint64_t) ms.ullTotalVirtual));
3636   }
3637 
3638   OSVERSIONINFOEX oi;
3639   oi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
3640   GetVersionEx((OSVERSIONINFO*)&oi);
3641   switch (oi.dwPlatformId) {
3642   case VER_PLATFORM_WIN32_NT:
3643     {
3644       int os_vers = oi.dwMajorVersion * 1000 + oi.dwMinorVersion;
3645       if (oi.wProductType == VER_NT_DOMAIN_CONTROLLER ||
3646           oi.wProductType == VER_NT_SERVER) {
3647         _is_windows_server = true;
3648       }
3649     }
3650     break;
3651   default: fatal("Unknown platform");
3652   }
3653 
3654   _default_stack_size = os::current_stack_size();
3655   assert(_default_stack_size > (size_t) _vm_page_size, "invalid stack size");
3656   assert((_default_stack_size & (_vm_page_size - 1)) == 0,
3657          "stack size not a multiple of page size");
3658 
3659   initialize_performance_counter();
3660 }
3661 
3662 
3663 HINSTANCE os::win32::load_Windows_dll(const char* name, char *ebuf,
3664                                       int ebuflen) {
3665   char path[MAX_PATH];
3666   DWORD size;
3667   DWORD pathLen = (DWORD)sizeof(path);
3668   HINSTANCE result = NULL;
3669 
3670   // only allow library name without path component
3671   assert(strchr(name, '\\') == NULL, "path not allowed");
3672   assert(strchr(name, ':') == NULL, "path not allowed");
3673   if (strchr(name, '\\') != NULL || strchr(name, ':') != NULL) {
3674     jio_snprintf(ebuf, ebuflen,
3675                  "Invalid parameter while calling os::win32::load_windows_dll(): cannot take path: %s", name);
3676     return NULL;
3677   }
3678 
3679   // search system directory
3680   if ((size = GetSystemDirectory(path, pathLen)) > 0) {
3681     if (size >= pathLen) {
3682       return NULL; // truncated
3683     }
3684     if (jio_snprintf(path + size, pathLen - size, "\\%s", name) == -1) {
3685       return NULL; // truncated
3686     }
3687     if ((result = (HINSTANCE)os::dll_load(path, ebuf, ebuflen)) != NULL) {
3688       return result;
3689     }
3690   }
3691 
3692   // try Windows directory
3693   if ((size = GetWindowsDirectory(path, pathLen)) > 0) {
3694     if (size >= pathLen) {
3695       return NULL; // truncated
3696     }
3697     if (jio_snprintf(path + size, pathLen - size, "\\%s", name) == -1) {
3698       return NULL; // truncated
3699     }
3700     if ((result = (HINSTANCE)os::dll_load(path, ebuf, ebuflen)) != NULL) {
3701       return result;
3702     }
3703   }
3704 
3705   jio_snprintf(ebuf, ebuflen,
3706                "os::win32::load_windows_dll() cannot load %s from system directories.", name);
3707   return NULL;
3708 }
3709 
3710 #define MAXIMUM_THREADS_TO_KEEP (16 * MAXIMUM_WAIT_OBJECTS)
3711 #define EXIT_TIMEOUT 300000 /* 5 minutes */
3712 
3713 static BOOL CALLBACK init_crit_sect_call(PINIT_ONCE, PVOID pcrit_sect, PVOID*) {
3714   InitializeCriticalSection((CRITICAL_SECTION*)pcrit_sect);
3715   return TRUE;
3716 }
3717 
3718 int os::win32::exit_process_or_thread(Ept what, int exit_code) {
3719   // Basic approach:
3720   //  - Each exiting thread registers its intent to exit and then does so.
3721   //  - A thread trying to terminate the process must wait for all
3722   //    threads currently exiting to complete their exit.
3723 
3724   if (os::win32::has_exit_bug()) {
3725     // The array holds handles of the threads that have started exiting by calling
3726     // _endthreadex().
3727     // Should be large enough to avoid blocking the exiting thread due to lack of
3728     // a free slot.
3729     static HANDLE handles[MAXIMUM_THREADS_TO_KEEP];
3730     static int handle_count = 0;
3731 
3732     static INIT_ONCE init_once_crit_sect = INIT_ONCE_STATIC_INIT;
3733     static CRITICAL_SECTION crit_sect;
3734     static volatile DWORD process_exiting = 0;
3735     int i, j;
3736     DWORD res;
3737     HANDLE hproc, hthr;
3738 
3739     // We only attempt to register threads until a process exiting
3740     // thread manages to set the process_exiting flag. Any threads
3741     // that come through here after the process_exiting flag is set
3742     // are unregistered and will be caught in the SuspendThread()
3743     // infinite loop below.
3744     bool registered = false;
3745 
3746     // The first thread that reached this point, initializes the critical section.
3747     if (!InitOnceExecuteOnce(&init_once_crit_sect, init_crit_sect_call, &crit_sect, NULL)) {
3748       warning("crit_sect initialization failed in %s: %d\n", __FILE__, __LINE__);
3749     } else if (OrderAccess::load_acquire(&process_exiting) == 0) {
3750       if (what != EPT_THREAD) {
3751         // Atomically set process_exiting before the critical section
3752         // to increase the visibility between racing threads.
3753         Atomic::cmpxchg(GetCurrentThreadId(), &process_exiting, (DWORD)0);
3754       }
3755       EnterCriticalSection(&crit_sect);
3756 
3757       if (what == EPT_THREAD && OrderAccess::load_acquire(&process_exiting) == 0) {
3758         // Remove from the array those handles of the threads that have completed exiting.
3759         for (i = 0, j = 0; i < handle_count; ++i) {
3760           res = WaitForSingleObject(handles[i], 0 /* don't wait */);
3761           if (res == WAIT_TIMEOUT) {
3762             handles[j++] = handles[i];
3763           } else {
3764             if (res == WAIT_FAILED) {
3765               warning("WaitForSingleObject failed (%u) in %s: %d\n",
3766                       GetLastError(), __FILE__, __LINE__);
3767             }
3768             // Don't keep the handle, if we failed waiting for it.
3769             CloseHandle(handles[i]);
3770           }
3771         }
3772 
3773         // If there's no free slot in the array of the kept handles, we'll have to
3774         // wait until at least one thread completes exiting.
3775         if ((handle_count = j) == MAXIMUM_THREADS_TO_KEEP) {
3776           // Raise the priority of the oldest exiting thread to increase its chances
3777           // to complete sooner.
3778           SetThreadPriority(handles[0], THREAD_PRIORITY_ABOVE_NORMAL);
3779           res = WaitForMultipleObjects(MAXIMUM_WAIT_OBJECTS, handles, FALSE, EXIT_TIMEOUT);
3780           if (res >= WAIT_OBJECT_0 && res < (WAIT_OBJECT_0 + MAXIMUM_WAIT_OBJECTS)) {
3781             i = (res - WAIT_OBJECT_0);
3782             handle_count = MAXIMUM_THREADS_TO_KEEP - 1;
3783             for (; i < handle_count; ++i) {
3784               handles[i] = handles[i + 1];
3785             }
3786           } else {
3787             warning("WaitForMultipleObjects %s (%u) in %s: %d\n",
3788                     (res == WAIT_FAILED ? "failed" : "timed out"),
3789                     GetLastError(), __FILE__, __LINE__);
3790             // Don't keep handles, if we failed waiting for them.
3791             for (i = 0; i < MAXIMUM_THREADS_TO_KEEP; ++i) {
3792               CloseHandle(handles[i]);
3793             }
3794             handle_count = 0;
3795           }
3796         }
3797 
3798         // Store a duplicate of the current thread handle in the array of handles.
3799         hproc = GetCurrentProcess();
3800         hthr = GetCurrentThread();
3801         if (!DuplicateHandle(hproc, hthr, hproc, &handles[handle_count],
3802                              0, FALSE, DUPLICATE_SAME_ACCESS)) {
3803           warning("DuplicateHandle failed (%u) in %s: %d\n",
3804                   GetLastError(), __FILE__, __LINE__);
3805 
3806           // We can't register this thread (no more handles) so this thread
3807           // may be racing with a thread that is calling exit(). If the thread
3808           // that is calling exit() has managed to set the process_exiting
3809           // flag, then this thread will be caught in the SuspendThread()
3810           // infinite loop below which closes that race. A small timing
3811           // window remains before the process_exiting flag is set, but it
3812           // is only exposed when we are out of handles.
3813         } else {
3814           ++handle_count;
3815           registered = true;
3816 
3817           // The current exiting thread has stored its handle in the array, and now
3818           // should leave the critical section before calling _endthreadex().
3819         }
3820 
3821       } else if (what != EPT_THREAD && handle_count > 0) {
3822         jlong start_time, finish_time, timeout_left;
3823         // Before ending the process, make sure all the threads that had called
3824         // _endthreadex() completed.
3825 
3826         // Set the priority level of the current thread to the same value as
3827         // the priority level of exiting threads.
3828         // This is to ensure it will be given a fair chance to execute if
3829         // the timeout expires.
3830         hthr = GetCurrentThread();
3831         SetThreadPriority(hthr, THREAD_PRIORITY_ABOVE_NORMAL);
3832         start_time = os::javaTimeNanos();
3833         finish_time = start_time + ((jlong)EXIT_TIMEOUT * 1000000L);
3834         for (i = 0; ; ) {
3835           int portion_count = handle_count - i;
3836           if (portion_count > MAXIMUM_WAIT_OBJECTS) {
3837             portion_count = MAXIMUM_WAIT_OBJECTS;
3838           }
3839           for (j = 0; j < portion_count; ++j) {
3840             SetThreadPriority(handles[i + j], THREAD_PRIORITY_ABOVE_NORMAL);
3841           }
3842           timeout_left = (finish_time - start_time) / 1000000L;
3843           if (timeout_left < 0) {
3844             timeout_left = 0;
3845           }
3846           res = WaitForMultipleObjects(portion_count, handles + i, TRUE, timeout_left);
3847           if (res == WAIT_FAILED || res == WAIT_TIMEOUT) {
3848             warning("WaitForMultipleObjects %s (%u) in %s: %d\n",
3849                     (res == WAIT_FAILED ? "failed" : "timed out"),
3850                     GetLastError(), __FILE__, __LINE__);
3851             // Reset portion_count so we close the remaining
3852             // handles due to this error.
3853             portion_count = handle_count - i;
3854           }
3855           for (j = 0; j < portion_count; ++j) {
3856             CloseHandle(handles[i + j]);
3857           }
3858           if ((i += portion_count) >= handle_count) {
3859             break;
3860           }
3861           start_time = os::javaTimeNanos();
3862         }
3863         handle_count = 0;
3864       }
3865 
3866       LeaveCriticalSection(&crit_sect);
3867     }
3868 
3869     if (!registered &&
3870         OrderAccess::load_acquire(&process_exiting) != 0 &&
3871         process_exiting != GetCurrentThreadId()) {
3872       // Some other thread is about to call exit(), so we don't let
3873       // the current unregistered thread proceed to exit() or _endthreadex()
3874       while (true) {
3875         SuspendThread(GetCurrentThread());
3876         // Avoid busy-wait loop, if SuspendThread() failed.
3877         Sleep(EXIT_TIMEOUT);
3878       }
3879     }
3880   }
3881 
3882   // We are here if either
3883   // - there's no 'race at exit' bug on this OS release;
3884   // - initialization of the critical section failed (unlikely);
3885   // - the current thread has registered itself and left the critical section;
3886   // - the process-exiting thread has raised the flag and left the critical section.
3887   if (what == EPT_THREAD) {
3888     _endthreadex((unsigned)exit_code);
3889   } else if (what == EPT_PROCESS) {
3890     ::exit(exit_code);
3891   } else {
3892     _exit(exit_code);
3893   }
3894 
3895   // Should not reach here
3896   return exit_code;
3897 }
3898 
3899 #undef EXIT_TIMEOUT
3900 
3901 void os::win32::setmode_streams() {
3902   _setmode(_fileno(stdin), _O_BINARY);
3903   _setmode(_fileno(stdout), _O_BINARY);
3904   _setmode(_fileno(stderr), _O_BINARY);
3905 }
3906 
3907 
3908 bool os::is_debugger_attached() {
3909   return IsDebuggerPresent() ? true : false;
3910 }
3911 
3912 
3913 void os::wait_for_keypress_at_exit(void) {
3914   if (PauseAtExit) {
3915     fprintf(stderr, "Press any key to continue...\n");
3916     fgetc(stdin);
3917   }
3918 }
3919 
3920 
3921 bool os::message_box(const char* title, const char* message) {
3922   int result = MessageBox(NULL, message, title,
3923                           MB_YESNO | MB_ICONERROR | MB_SYSTEMMODAL | MB_DEFAULT_DESKTOP_ONLY);
3924   return result == IDYES;
3925 }
3926 
3927 #ifndef PRODUCT
3928 #ifndef _WIN64
3929 // Helpers to check whether NX protection is enabled
3930 int nx_exception_filter(_EXCEPTION_POINTERS *pex) {
3931   if (pex->ExceptionRecord->ExceptionCode == EXCEPTION_ACCESS_VIOLATION &&
3932       pex->ExceptionRecord->NumberParameters > 0 &&
3933       pex->ExceptionRecord->ExceptionInformation[0] ==
3934       EXCEPTION_INFO_EXEC_VIOLATION) {
3935     return EXCEPTION_EXECUTE_HANDLER;
3936   }
3937   return EXCEPTION_CONTINUE_SEARCH;
3938 }
3939 
3940 void nx_check_protection() {
3941   // If NX is enabled we'll get an exception calling into code on the stack
3942   char code[] = { (char)0xC3 }; // ret
3943   void *code_ptr = (void *)code;
3944   __try {
3945     __asm call code_ptr
3946   } __except(nx_exception_filter((_EXCEPTION_POINTERS*)_exception_info())) {
3947     tty->print_raw_cr("NX protection detected.");
3948   }
3949 }
3950 #endif // _WIN64
3951 #endif // PRODUCT
3952 
3953 // This is called _before_ the global arguments have been parsed
3954 void os::init(void) {
3955   _initial_pid = _getpid();
3956 
3957   init_random(1234567);
3958 
3959   win32::initialize_system_info();
3960   win32::setmode_streams();
3961   init_page_sizes((size_t) win32::vm_page_size());
3962 
3963   // This may be overridden later when argument processing is done.
3964   FLAG_SET_ERGO(UseLargePagesIndividualAllocation, false);
3965 
3966   // Initialize main_process and main_thread
3967   main_process = GetCurrentProcess();  // Remember main_process is a pseudo handle
3968   if (!DuplicateHandle(main_process, GetCurrentThread(), main_process,
3969                        &main_thread, THREAD_ALL_ACCESS, false, 0)) {
3970     fatal("DuplicateHandle failed\n");
3971   }
3972   main_thread_id = (int) GetCurrentThreadId();
3973 
3974   // initialize fast thread access - only used for 32-bit
3975   win32::initialize_thread_ptr_offset();
3976 }
3977 
3978 // To install functions for atexit processing
3979 extern "C" {
3980   static void perfMemory_exit_helper() {
3981     perfMemory_exit();
3982   }
3983 }
3984 
3985 static jint initSock();
3986 
3987 // this is called _after_ the global arguments have been parsed
3988 jint os::init_2(void) {
3989 
3990   // This could be set any time but all platforms
3991   // have to set it the same so we have to mirror Solaris.
3992   DEBUG_ONLY(os::set_mutex_init_done();)
3993 
3994   // Setup Windows Exceptions
3995 
3996 #if INCLUDE_AOT
3997   // If AOT is enabled we need to install a vectored exception handler
3998   // in order to forward implicit exceptions from code in AOT
3999   // generated DLLs.  This is necessary since these DLLs are not
4000   // registered for structured exceptions like codecache methods are.
4001   if (AOTLibrary != NULL && (UseAOT || FLAG_IS_DEFAULT(UseAOT))) {
4002     topLevelVectoredExceptionHandler = AddVectoredExceptionHandler( 1, topLevelVectoredExceptionFilter);
4003   }
4004 #endif
4005 
4006   // for debugging float code generation bugs
4007   if (ForceFloatExceptions) {
4008 #ifndef  _WIN64
4009     static long fp_control_word = 0;
4010     __asm { fstcw fp_control_word }
4011     // see Intel PPro Manual, Vol. 2, p 7-16
4012     const long precision = 0x20;
4013     const long underflow = 0x10;
4014     const long overflow  = 0x08;
4015     const long zero_div  = 0x04;
4016     const long denorm    = 0x02;
4017     const long invalid   = 0x01;
4018     fp_control_word |= invalid;
4019     __asm { fldcw fp_control_word }
4020 #endif
4021   }
4022 
4023   // If stack_commit_size is 0, windows will reserve the default size,
4024   // but only commit a small portion of it.
4025   size_t stack_commit_size = align_up(ThreadStackSize*K, os::vm_page_size());
4026   size_t default_reserve_size = os::win32::default_stack_size();
4027   size_t actual_reserve_size = stack_commit_size;
4028   if (stack_commit_size < default_reserve_size) {
4029     // If stack_commit_size == 0, we want this too
4030     actual_reserve_size = default_reserve_size;
4031   }
4032 
4033   // Check minimum allowable stack size for thread creation and to initialize
4034   // the java system classes, including StackOverflowError - depends on page
4035   // size.  Add two 4K pages for compiler2 recursion in main thread.
4036   // Add in 4*BytesPerWord 4K pages to account for VM stack during
4037   // class initialization depending on 32 or 64 bit VM.
4038   size_t min_stack_allowed =
4039             (size_t)(JavaThread::stack_guard_zone_size() +
4040                      JavaThread::stack_shadow_zone_size() +
4041                      (4*BytesPerWord COMPILER2_PRESENT(+2)) * 4 * K);
4042 
4043   min_stack_allowed = align_up(min_stack_allowed, os::vm_page_size());
4044 
4045   if (actual_reserve_size < min_stack_allowed) {
4046     tty->print_cr("\nThe Java thread stack size specified is too small. "
4047                   "Specify at least %dk",
4048                   min_stack_allowed / K);
4049     return JNI_ERR;
4050   }
4051 
4052   JavaThread::set_stack_size_at_create(stack_commit_size);
4053 
4054   // Calculate theoretical max. size of Threads to guard gainst artifical
4055   // out-of-memory situations, where all available address-space has been
4056   // reserved by thread stacks.
4057   assert(actual_reserve_size != 0, "Must have a stack");
4058 
4059   // Calculate the thread limit when we should start doing Virtual Memory
4060   // banging. Currently when the threads will have used all but 200Mb of space.
4061   //
4062   // TODO: consider performing a similar calculation for commit size instead
4063   // as reserve size, since on a 64-bit platform we'll run into that more
4064   // often than running out of virtual memory space.  We can use the
4065   // lower value of the two calculations as the os_thread_limit.
4066   size_t max_address_space = ((size_t)1 << (BitsPerWord - 1)) - (200 * K * K);
4067   win32::_os_thread_limit = (intx)(max_address_space / actual_reserve_size);
4068 
4069   // at exit methods are called in the reverse order of their registration.
4070   // there is no limit to the number of functions registered. atexit does
4071   // not set errno.
4072 
4073   if (PerfAllowAtExitRegistration) {
4074     // only register atexit functions if PerfAllowAtExitRegistration is set.
4075     // atexit functions can be delayed until process exit time, which
4076     // can be problematic for embedded VM situations. Embedded VMs should
4077     // call DestroyJavaVM() to assure that VM resources are released.
4078 
4079     // note: perfMemory_exit_helper atexit function may be removed in
4080     // the future if the appropriate cleanup code can be added to the
4081     // VM_Exit VMOperation's doit method.
4082     if (atexit(perfMemory_exit_helper) != 0) {
4083       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
4084     }
4085   }
4086 
4087 #ifndef _WIN64
4088   // Print something if NX is enabled (win32 on AMD64)
4089   NOT_PRODUCT(if (PrintMiscellaneous && Verbose) nx_check_protection());
4090 #endif
4091 
4092   // initialize thread priority policy
4093   prio_init();
4094 
4095   if (UseNUMA && !ForceNUMA) {
4096     UseNUMA = false; // We don't fully support this yet
4097   }
4098 
4099   if (UseNUMAInterleaving) {
4100     // first check whether this Windows OS supports VirtualAllocExNuma, if not ignore this flag
4101     bool success = numa_interleaving_init();
4102     if (!success) UseNUMAInterleaving = false;
4103   }
4104 
4105   if (initSock() != JNI_OK) {
4106     return JNI_ERR;
4107   }
4108 
4109   SymbolEngine::recalc_search_path();
4110 
4111   // Initialize data for jdk.internal.misc.Signal
4112   if (!ReduceSignalUsage) {
4113     jdk_misc_signal_init();
4114   }
4115 
4116   return JNI_OK;
4117 }
4118 
4119 // Mark the polling page as unreadable
4120 void os::make_polling_page_unreadable(void) {
4121   DWORD old_status;
4122   if (!VirtualProtect((char *)_polling_page, os::vm_page_size(),
4123                       PAGE_NOACCESS, &old_status)) {
4124     fatal("Could not disable polling page");
4125   }
4126 }
4127 
4128 // Mark the polling page as readable
4129 void os::make_polling_page_readable(void) {
4130   DWORD old_status;
4131   if (!VirtualProtect((char *)_polling_page, os::vm_page_size(),
4132                       PAGE_READONLY, &old_status)) {
4133     fatal("Could not enable polling page");
4134   }
4135 }
4136 
4137 // combine the high and low DWORD into a ULONGLONG
4138 static ULONGLONG make_double_word(DWORD high_word, DWORD low_word) {
4139   ULONGLONG value = high_word;
4140   value <<= sizeof(high_word) * 8;
4141   value |= low_word;
4142   return value;
4143 }
4144 
4145 // Transfers data from WIN32_FILE_ATTRIBUTE_DATA structure to struct stat
4146 static void file_attribute_data_to_stat(struct stat* sbuf, WIN32_FILE_ATTRIBUTE_DATA file_data) {
4147   ::memset((void*)sbuf, 0, sizeof(struct stat));
4148   sbuf->st_size = (_off_t)make_double_word(file_data.nFileSizeHigh, file_data.nFileSizeLow);
4149   sbuf->st_mtime = make_double_word(file_data.ftLastWriteTime.dwHighDateTime,
4150                                   file_data.ftLastWriteTime.dwLowDateTime);
4151   sbuf->st_ctime = make_double_word(file_data.ftCreationTime.dwHighDateTime,
4152                                   file_data.ftCreationTime.dwLowDateTime);
4153   sbuf->st_atime = make_double_word(file_data.ftLastAccessTime.dwHighDateTime,
4154                                   file_data.ftLastAccessTime.dwLowDateTime);
4155   if ((file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0) {
4156     sbuf->st_mode |= S_IFDIR;
4157   } else {
4158     sbuf->st_mode |= S_IFREG;
4159   }
4160 }
4161 
4162 // Returns the given path as an absolute wide path in unc format. The returned path is NULL
4163 // on error (with err being set accordingly) and should be freed via os::free() otherwise.
4164 // additional_space is the number of additionally allocated wchars after the terminating L'\0'.
4165 // This is based on pathToNTPath() in io_util_md.cpp, but omits the optimizations for
4166 // short paths.
4167 static wchar_t* wide_abs_unc_path(char const* path, errno_t & err, int additional_space = 0) {
4168   if ((path == NULL) || (path[0] == '\0')) {
4169     err = ENOENT;
4170     return NULL;
4171   }
4172 
4173   size_t path_len = strlen(path);
4174   // Need to allocate at least room for 3 characters, since os::native_path transforms C: to C:.
4175   char* buf = (char*) os::malloc(1 + MAX2((size_t) 3, path_len), mtInternal);
4176   wchar_t* result = NULL;
4177 
4178   if (buf == NULL) {
4179     err = ENOMEM;
4180   } else {
4181     memcpy(buf, path, path_len + 1);
4182     os::native_path(buf);
4183 
4184     wchar_t* prefix;
4185     int prefix_off = 0;
4186     bool is_abs = true;
4187     bool needs_fullpath = true;
4188 
4189     if (::isalpha(buf[0]) && !::IsDBCSLeadByte(buf[0]) && buf[1] == ':' && buf[2] == '\\') {
4190       prefix = L"\\\\?\\";
4191     } else if (buf[0] == '\\' && buf[1] == '\\') {
4192       assert(buf[2] != '\\');
4193 
4194       if (buf[2] == '?' && buf[3] == '\\') {
4195         prefix = L"";
4196         needs_fullpath = false;
4197       } else {
4198         prefix = L"\\\\?\\UNC";
4199         prefix_off = 1; // Overwrite the first char with the prefix, so \\share\path becomes \\?\UNC\share\path
4200       }
4201     } else {
4202       is_abs = false;
4203       prefix = L"\\\\?\\";
4204     }
4205 
4206     size_t buf_len = strlen(buf);
4207     size_t prefix_len = wcslen(prefix);
4208     size_t full_path_size = is_abs ? 1 + buf_len : JVM_MAXPATHLEN;
4209     size_t result_size = prefix_len + full_path_size - prefix_off;
4210     result = (wchar_t*) os::malloc(sizeof(wchar_t) * (additional_space + result_size), mtInternal);
4211 
4212     if (result == NULL) {
4213       err = ENOMEM;
4214     } else {
4215       size_t converted_chars;
4216       wchar_t* path_start = result + prefix_len - prefix_off;
4217       err = ::mbstowcs_s(&converted_chars, path_start, buf_len + 1, buf, buf_len);
4218 
4219       if ((err == ERROR_SUCCESS) && needs_fullpath) {
4220         wchar_t* tmp = (wchar_t*) os::malloc(sizeof(wchar_t) * full_path_size, mtInternal);
4221 
4222         if (tmp == NULL) {
4223           err = ENOMEM;
4224         } else {
4225           if (!_wfullpath(tmp, path_start, full_path_size)) {
4226             err = ENOENT;
4227           } else {
4228             ::memcpy(path_start, tmp, (1 + wcslen(tmp)) * sizeof(wchar_t));
4229           }
4230 
4231           os::free(tmp);
4232         }
4233       }
4234 
4235       memcpy(result, prefix, sizeof(wchar_t) * prefix_len);
4236 
4237       // Remove trailing pathsep (not for \\?\<DRIVE>:\, since it would make it relative)
4238       size_t result_len = wcslen(result);
4239 
4240       if (result[result_len - 1] == L'\\') {
4241         if (!(::iswalpha(result[4]) && result[5] == L':' && result_len == 7)) {
4242           result[result_len - 1] = L'\0';
4243         }
4244       }
4245     }
4246   }
4247 
4248   os::free(buf);
4249 
4250   if (err != ERROR_SUCCESS) {
4251     os::free(result);
4252     result = NULL;
4253   }
4254 
4255   return result;
4256 }
4257 
4258 int os::stat(const char *path, struct stat *sbuf) {
4259   errno_t err;
4260   wchar_t* wide_path = wide_abs_unc_path(path, err);
4261 
4262   if (wide_path == NULL) {
4263     errno = err;
4264     return -1;
4265   }
4266 
4267   WIN32_FILE_ATTRIBUTE_DATA file_data;;
4268   BOOL bret = ::GetFileAttributesExW(wide_path, GetFileExInfoStandard, &file_data);
4269   os::free(wide_path);
4270 
4271   if (!bret) {
4272     errno = ::GetLastError();
4273     return -1;
4274   }
4275 
4276   file_attribute_data_to_stat(sbuf, file_data);
4277   return 0;
4278 }
4279 
4280 static HANDLE create_read_only_file_handle(const char* file) {
4281   errno_t err;
4282   wchar_t* wide_path = wide_abs_unc_path(file, err);
4283 
4284   if (wide_path == NULL) {
4285     errno = err;
4286     return INVALID_HANDLE_VALUE;
4287   }
4288 
4289   HANDLE handle = ::CreateFileW(wide_path, 0, FILE_SHARE_READ,
4290                                 NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
4291   os::free(wide_path);
4292 
4293   return handle;
4294 }
4295 
4296 bool os::same_files(const char* file1, const char* file2) {
4297 
4298   if (file1 == NULL && file2 == NULL) {
4299     return true;
4300   }
4301 
4302   if (file1 == NULL || file2 == NULL) {
4303     return false;
4304   }
4305 
4306   if (strcmp(file1, file2) == 0) {
4307     return true;
4308   }
4309 
4310   HANDLE handle1 = create_read_only_file_handle(file1);
4311   HANDLE handle2 = create_read_only_file_handle(file2);
4312   bool result = false;
4313 
4314   // if we could open both paths...
4315   if (handle1 != INVALID_HANDLE_VALUE && handle2 != INVALID_HANDLE_VALUE) {
4316     BY_HANDLE_FILE_INFORMATION fileInfo1;
4317     BY_HANDLE_FILE_INFORMATION fileInfo2;
4318     if (::GetFileInformationByHandle(handle1, &fileInfo1) &&
4319       ::GetFileInformationByHandle(handle2, &fileInfo2)) {
4320       // the paths are the same if they refer to the same file (fileindex) on the same volume (volume serial number)
4321       if (fileInfo1.dwVolumeSerialNumber == fileInfo2.dwVolumeSerialNumber &&
4322         fileInfo1.nFileIndexHigh == fileInfo2.nFileIndexHigh &&
4323         fileInfo1.nFileIndexLow == fileInfo2.nFileIndexLow) {
4324         result = true;
4325       }
4326     }
4327   }
4328 
4329   //free the handles
4330   if (handle1 != INVALID_HANDLE_VALUE) {
4331     ::CloseHandle(handle1);
4332   }
4333 
4334   if (handle2 != INVALID_HANDLE_VALUE) {
4335     ::CloseHandle(handle2);
4336   }
4337 
4338   return result;
4339 }
4340 
4341 #define FT2INT64(ft) \
4342   ((jlong)((jlong)(ft).dwHighDateTime << 32 | (julong)(ft).dwLowDateTime))
4343 
4344 
4345 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
4346 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
4347 // of a thread.
4348 //
4349 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
4350 // the fast estimate available on the platform.
4351 
4352 // current_thread_cpu_time() is not optimized for Windows yet
4353 jlong os::current_thread_cpu_time() {
4354   // return user + sys since the cost is the same
4355   return os::thread_cpu_time(Thread::current(), true /* user+sys */);
4356 }
4357 
4358 jlong os::thread_cpu_time(Thread* thread) {
4359   // consistent with what current_thread_cpu_time() returns.
4360   return os::thread_cpu_time(thread, true /* user+sys */);
4361 }
4362 
4363 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
4364   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
4365 }
4366 
4367 jlong os::thread_cpu_time(Thread* thread, bool user_sys_cpu_time) {
4368   // This code is copy from clasic VM -> hpi::sysThreadCPUTime
4369   // If this function changes, os::is_thread_cpu_time_supported() should too
4370   FILETIME CreationTime;
4371   FILETIME ExitTime;
4372   FILETIME KernelTime;
4373   FILETIME UserTime;
4374 
4375   if (GetThreadTimes(thread->osthread()->thread_handle(), &CreationTime,
4376                       &ExitTime, &KernelTime, &UserTime) == 0) {
4377     return -1;
4378   } else if (user_sys_cpu_time) {
4379     return (FT2INT64(UserTime) + FT2INT64(KernelTime)) * 100;
4380   } else {
4381     return FT2INT64(UserTime) * 100;
4382   }
4383 }
4384 
4385 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4386   info_ptr->max_value = ALL_64_BITS;        // the max value -- all 64 bits
4387   info_ptr->may_skip_backward = false;      // GetThreadTimes returns absolute time
4388   info_ptr->may_skip_forward = false;       // GetThreadTimes returns absolute time
4389   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;   // user+system time is returned
4390 }
4391 
4392 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4393   info_ptr->max_value = ALL_64_BITS;        // the max value -- all 64 bits
4394   info_ptr->may_skip_backward = false;      // GetThreadTimes returns absolute time
4395   info_ptr->may_skip_forward = false;       // GetThreadTimes returns absolute time
4396   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;   // user+system time is returned
4397 }
4398 
4399 bool os::is_thread_cpu_time_supported() {
4400   // see os::thread_cpu_time
4401   FILETIME CreationTime;
4402   FILETIME ExitTime;
4403   FILETIME KernelTime;
4404   FILETIME UserTime;
4405 
4406   if (GetThreadTimes(GetCurrentThread(), &CreationTime, &ExitTime,
4407                       &KernelTime, &UserTime) == 0) {
4408     return false;
4409   } else {
4410     return true;
4411   }
4412 }
4413 
4414 // Windows does't provide a loadavg primitive so this is stubbed out for now.
4415 // It does have primitives (PDH API) to get CPU usage and run queue length.
4416 // "\\Processor(_Total)\\% Processor Time", "\\System\\Processor Queue Length"
4417 // If we wanted to implement loadavg on Windows, we have a few options:
4418 //
4419 // a) Query CPU usage and run queue length and "fake" an answer by
4420 //    returning the CPU usage if it's under 100%, and the run queue
4421 //    length otherwise.  It turns out that querying is pretty slow
4422 //    on Windows, on the order of 200 microseconds on a fast machine.
4423 //    Note that on the Windows the CPU usage value is the % usage
4424 //    since the last time the API was called (and the first call
4425 //    returns 100%), so we'd have to deal with that as well.
4426 //
4427 // b) Sample the "fake" answer using a sampling thread and store
4428 //    the answer in a global variable.  The call to loadavg would
4429 //    just return the value of the global, avoiding the slow query.
4430 //
4431 // c) Sample a better answer using exponential decay to smooth the
4432 //    value.  This is basically the algorithm used by UNIX kernels.
4433 //
4434 // Note that sampling thread starvation could affect both (b) and (c).
4435 int os::loadavg(double loadavg[], int nelem) {
4436   return -1;
4437 }
4438 
4439 
4440 // DontYieldALot=false by default: dutifully perform all yields as requested by JVM_Yield()
4441 bool os::dont_yield() {
4442   return DontYieldALot;
4443 }
4444 
4445 int os::open(const char *path, int oflag, int mode) {
4446   errno_t err;
4447   wchar_t* wide_path = wide_abs_unc_path(path, err);
4448 
4449   if (wide_path == NULL) {
4450     errno = err;
4451     return -1;
4452   }
4453   int fd = ::_wopen(wide_path, oflag | O_BINARY | O_NOINHERIT, mode);
4454   os::free(wide_path);
4455 
4456   if (fd == -1) {
4457     errno = ::GetLastError();
4458   }
4459 
4460   return fd;
4461 }
4462 
4463 FILE* os::open(int fd, const char* mode) {
4464   return ::_fdopen(fd, mode);
4465 }
4466 
4467 // Is a (classpath) directory empty?
4468 bool os::dir_is_empty(const char* path) {
4469   errno_t err;
4470   wchar_t* wide_path = wide_abs_unc_path(path, err, 2);
4471 
4472   if (wide_path == NULL) {
4473     errno = err;
4474     return false;
4475   }
4476 
4477   // Make sure we end with "\\*"
4478   if (wide_path[wcslen(wide_path) - 1] == L'\\') {
4479     wcscat(wide_path, L"*");
4480   } else {
4481     wcscat(wide_path, L"\\*");
4482   }
4483 
4484   WIN32_FIND_DATAW fd;
4485   HANDLE f = ::FindFirstFileW(wide_path, &fd);
4486   os::free(wide_path);
4487   bool is_empty = true;
4488 
4489   if (f != INVALID_HANDLE_VALUE) {
4490     while (is_empty && ::FindNextFileW(f, &fd)) {
4491       // An empty directory contains only the current directory file
4492       // and the previous directory file.
4493       if ((wcscmp(fd.cFileName, L".") != 0) &&
4494           (wcscmp(fd.cFileName, L"..") != 0)) {
4495         is_empty = false;
4496       }
4497     }
4498     FindClose(f);
4499   } else {
4500     errno = ::GetLastError();
4501   }
4502 
4503   return is_empty;
4504 }
4505 
4506 // create binary file, rewriting existing file if required
4507 int os::create_binary_file(const char* path, bool rewrite_existing) {
4508   int oflags = _O_CREAT | _O_WRONLY | _O_BINARY;
4509   if (!rewrite_existing) {
4510     oflags |= _O_EXCL;
4511   }
4512   return ::open(path, oflags, _S_IREAD | _S_IWRITE);
4513 }
4514 
4515 // return current position of file pointer
4516 jlong os::current_file_offset(int fd) {
4517   return (jlong)::_lseeki64(fd, (__int64)0L, SEEK_CUR);
4518 }
4519 
4520 // move file pointer to the specified offset
4521 jlong os::seek_to_file_offset(int fd, jlong offset) {
4522   return (jlong)::_lseeki64(fd, (__int64)offset, SEEK_SET);
4523 }
4524 
4525 
4526 jlong os::lseek(int fd, jlong offset, int whence) {
4527   return (jlong) ::_lseeki64(fd, offset, whence);
4528 }
4529 
4530 ssize_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
4531   OVERLAPPED ov;
4532   DWORD nread;
4533   BOOL result;
4534 
4535   ZeroMemory(&ov, sizeof(ov));
4536   ov.Offset = (DWORD)offset;
4537   ov.OffsetHigh = (DWORD)(offset >> 32);
4538 
4539   HANDLE h = (HANDLE)::_get_osfhandle(fd);
4540 
4541   result = ReadFile(h, (LPVOID)buf, nBytes, &nread, &ov);
4542 
4543   return result ? nread : 0;
4544 }
4545 
4546 
4547 // This method is a slightly reworked copy of JDK's sysNativePath
4548 // from src/windows/hpi/src/path_md.c
4549 
4550 // Convert a pathname to native format.  On win32, this involves forcing all
4551 // separators to be '\\' rather than '/' (both are legal inputs, but Win95
4552 // sometimes rejects '/') and removing redundant separators.  The input path is
4553 // assumed to have been converted into the character encoding used by the local
4554 // system.  Because this might be a double-byte encoding, care is taken to
4555 // treat double-byte lead characters correctly.
4556 //
4557 // This procedure modifies the given path in place, as the result is never
4558 // longer than the original.  There is no error return; this operation always
4559 // succeeds.
4560 char * os::native_path(char *path) {
4561   char *src = path, *dst = path, *end = path;
4562   char *colon = NULL;  // If a drive specifier is found, this will
4563                        // point to the colon following the drive letter
4564 
4565   // Assumption: '/', '\\', ':', and drive letters are never lead bytes
4566   assert(((!::IsDBCSLeadByte('/')) && (!::IsDBCSLeadByte('\\'))
4567           && (!::IsDBCSLeadByte(':'))), "Illegal lead byte");
4568 
4569   // Check for leading separators
4570 #define isfilesep(c) ((c) == '/' || (c) == '\\')
4571   while (isfilesep(*src)) {
4572     src++;
4573   }
4574 
4575   if (::isalpha(*src) && !::IsDBCSLeadByte(*src) && src[1] == ':') {
4576     // Remove leading separators if followed by drive specifier.  This
4577     // hack is necessary to support file URLs containing drive
4578     // specifiers (e.g., "file://c:/path").  As a side effect,
4579     // "/c:/path" can be used as an alternative to "c:/path".
4580     *dst++ = *src++;
4581     colon = dst;
4582     *dst++ = ':';
4583     src++;
4584   } else {
4585     src = path;
4586     if (isfilesep(src[0]) && isfilesep(src[1])) {
4587       // UNC pathname: Retain first separator; leave src pointed at
4588       // second separator so that further separators will be collapsed
4589       // into the second separator.  The result will be a pathname
4590       // beginning with "\\\\" followed (most likely) by a host name.
4591       src = dst = path + 1;
4592       path[0] = '\\';     // Force first separator to '\\'
4593     }
4594   }
4595 
4596   end = dst;
4597 
4598   // Remove redundant separators from remainder of path, forcing all
4599   // separators to be '\\' rather than '/'. Also, single byte space
4600   // characters are removed from the end of the path because those
4601   // are not legal ending characters on this operating system.
4602   //
4603   while (*src != '\0') {
4604     if (isfilesep(*src)) {
4605       *dst++ = '\\'; src++;
4606       while (isfilesep(*src)) src++;
4607       if (*src == '\0') {
4608         // Check for trailing separator
4609         end = dst;
4610         if (colon == dst - 2) break;  // "z:\\"
4611         if (dst == path + 1) break;   // "\\"
4612         if (dst == path + 2 && isfilesep(path[0])) {
4613           // "\\\\" is not collapsed to "\\" because "\\\\" marks the
4614           // beginning of a UNC pathname.  Even though it is not, by
4615           // itself, a valid UNC pathname, we leave it as is in order
4616           // to be consistent with the path canonicalizer as well
4617           // as the win32 APIs, which treat this case as an invalid
4618           // UNC pathname rather than as an alias for the root
4619           // directory of the current drive.
4620           break;
4621         }
4622         end = --dst;  // Path does not denote a root directory, so
4623                       // remove trailing separator
4624         break;
4625       }
4626       end = dst;
4627     } else {
4628       if (::IsDBCSLeadByte(*src)) {  // Copy a double-byte character
4629         *dst++ = *src++;
4630         if (*src) *dst++ = *src++;
4631         end = dst;
4632       } else {  // Copy a single-byte character
4633         char c = *src++;
4634         *dst++ = c;
4635         // Space is not a legal ending character
4636         if (c != ' ') end = dst;
4637       }
4638     }
4639   }
4640 
4641   *end = '\0';
4642 
4643   // For "z:", add "." to work around a bug in the C runtime library
4644   if (colon == dst - 1) {
4645     path[2] = '.';
4646     path[3] = '\0';
4647   }
4648 
4649   return path;
4650 }
4651 
4652 // This code is a copy of JDK's sysSetLength
4653 // from src/windows/hpi/src/sys_api_md.c
4654 
4655 int os::ftruncate(int fd, jlong length) {
4656   HANDLE h = (HANDLE)::_get_osfhandle(fd);
4657   long high = (long)(length >> 32);
4658   DWORD ret;
4659 
4660   if (h == (HANDLE)(-1)) {
4661     return -1;
4662   }
4663 
4664   ret = ::SetFilePointer(h, (long)(length), &high, FILE_BEGIN);
4665   if ((ret == 0xFFFFFFFF) && (::GetLastError() != NO_ERROR)) {
4666     return -1;
4667   }
4668 
4669   if (::SetEndOfFile(h) == FALSE) {
4670     return -1;
4671   }
4672 
4673   return 0;
4674 }
4675 
4676 int os::get_fileno(FILE* fp) {
4677   return _fileno(fp);
4678 }
4679 
4680 // This code is a copy of JDK's sysSync
4681 // from src/windows/hpi/src/sys_api_md.c
4682 // except for the legacy workaround for a bug in Win 98
4683 
4684 int os::fsync(int fd) {
4685   HANDLE handle = (HANDLE)::_get_osfhandle(fd);
4686 
4687   if ((!::FlushFileBuffers(handle)) &&
4688       (GetLastError() != ERROR_ACCESS_DENIED)) {
4689     // from winerror.h
4690     return -1;
4691   }
4692   return 0;
4693 }
4694 
4695 static int nonSeekAvailable(int, long *);
4696 static int stdinAvailable(int, long *);
4697 
4698 // This code is a copy of JDK's sysAvailable
4699 // from src/windows/hpi/src/sys_api_md.c
4700 
4701 int os::available(int fd, jlong *bytes) {
4702   jlong cur, end;
4703   struct _stati64 stbuf64;
4704 
4705   if (::_fstati64(fd, &stbuf64) >= 0) {
4706     int mode = stbuf64.st_mode;
4707     if (S_ISCHR(mode) || S_ISFIFO(mode)) {
4708       int ret;
4709       long lpbytes;
4710       if (fd == 0) {
4711         ret = stdinAvailable(fd, &lpbytes);
4712       } else {
4713         ret = nonSeekAvailable(fd, &lpbytes);
4714       }
4715       (*bytes) = (jlong)(lpbytes);
4716       return ret;
4717     }
4718     if ((cur = ::_lseeki64(fd, 0L, SEEK_CUR)) == -1) {
4719       return FALSE;
4720     } else if ((end = ::_lseeki64(fd, 0L, SEEK_END)) == -1) {
4721       return FALSE;
4722     } else if (::_lseeki64(fd, cur, SEEK_SET) == -1) {
4723       return FALSE;
4724     }
4725     *bytes = end - cur;
4726     return TRUE;
4727   } else {
4728     return FALSE;
4729   }
4730 }
4731 
4732 void os::flockfile(FILE* fp) {
4733   _lock_file(fp);
4734 }
4735 
4736 void os::funlockfile(FILE* fp) {
4737   _unlock_file(fp);
4738 }
4739 
4740 // This code is a copy of JDK's nonSeekAvailable
4741 // from src/windows/hpi/src/sys_api_md.c
4742 
4743 static int nonSeekAvailable(int fd, long *pbytes) {
4744   // This is used for available on non-seekable devices
4745   // (like both named and anonymous pipes, such as pipes
4746   //  connected to an exec'd process).
4747   // Standard Input is a special case.
4748   HANDLE han;
4749 
4750   if ((han = (HANDLE) ::_get_osfhandle(fd)) == (HANDLE)(-1)) {
4751     return FALSE;
4752   }
4753 
4754   if (! ::PeekNamedPipe(han, NULL, 0, NULL, (LPDWORD)pbytes, NULL)) {
4755     // PeekNamedPipe fails when at EOF.  In that case we
4756     // simply make *pbytes = 0 which is consistent with the
4757     // behavior we get on Solaris when an fd is at EOF.
4758     // The only alternative is to raise an Exception,
4759     // which isn't really warranted.
4760     //
4761     if (::GetLastError() != ERROR_BROKEN_PIPE) {
4762       return FALSE;
4763     }
4764     *pbytes = 0;
4765   }
4766   return TRUE;
4767 }
4768 
4769 #define MAX_INPUT_EVENTS 2000
4770 
4771 // This code is a copy of JDK's stdinAvailable
4772 // from src/windows/hpi/src/sys_api_md.c
4773 
4774 static int stdinAvailable(int fd, long *pbytes) {
4775   HANDLE han;
4776   DWORD numEventsRead = 0;  // Number of events read from buffer
4777   DWORD numEvents = 0;      // Number of events in buffer
4778   DWORD i = 0;              // Loop index
4779   DWORD curLength = 0;      // Position marker
4780   DWORD actualLength = 0;   // Number of bytes readable
4781   BOOL error = FALSE;       // Error holder
4782   INPUT_RECORD *lpBuffer;   // Pointer to records of input events
4783 
4784   if ((han = ::GetStdHandle(STD_INPUT_HANDLE)) == INVALID_HANDLE_VALUE) {
4785     return FALSE;
4786   }
4787 
4788   // Construct an array of input records in the console buffer
4789   error = ::GetNumberOfConsoleInputEvents(han, &numEvents);
4790   if (error == 0) {
4791     return nonSeekAvailable(fd, pbytes);
4792   }
4793 
4794   // lpBuffer must fit into 64K or else PeekConsoleInput fails
4795   if (numEvents > MAX_INPUT_EVENTS) {
4796     numEvents = MAX_INPUT_EVENTS;
4797   }
4798 
4799   lpBuffer = (INPUT_RECORD *)os::malloc(numEvents * sizeof(INPUT_RECORD), mtInternal);
4800   if (lpBuffer == NULL) {
4801     return FALSE;
4802   }
4803 
4804   error = ::PeekConsoleInput(han, lpBuffer, numEvents, &numEventsRead);
4805   if (error == 0) {
4806     os::free(lpBuffer);
4807     return FALSE;
4808   }
4809 
4810   // Examine input records for the number of bytes available
4811   for (i=0; i<numEvents; i++) {
4812     if (lpBuffer[i].EventType == KEY_EVENT) {
4813 
4814       KEY_EVENT_RECORD *keyRecord = (KEY_EVENT_RECORD *)
4815                                       &(lpBuffer[i].Event);
4816       if (keyRecord->bKeyDown == TRUE) {
4817         CHAR *keyPressed = (CHAR *) &(keyRecord->uChar);
4818         curLength++;
4819         if (*keyPressed == '\r') {
4820           actualLength = curLength;
4821         }
4822       }
4823     }
4824   }
4825 
4826   if (lpBuffer != NULL) {
4827     os::free(lpBuffer);
4828   }
4829 
4830   *pbytes = (long) actualLength;
4831   return TRUE;
4832 }
4833 
4834 // Map a block of memory.
4835 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
4836                         char *addr, size_t bytes, bool read_only,
4837                         bool allow_exec) {
4838   HANDLE hFile;
4839   char* base;
4840 
4841   hFile = CreateFile(file_name, GENERIC_READ, FILE_SHARE_READ, NULL,
4842                      OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
4843   if (hFile == NULL) {
4844     log_info(os)("CreateFile() failed: GetLastError->%ld.", GetLastError());
4845     return NULL;
4846   }
4847 
4848   if (allow_exec) {
4849     // CreateFileMapping/MapViewOfFileEx can't map executable memory
4850     // unless it comes from a PE image (which the shared archive is not.)
4851     // Even VirtualProtect refuses to give execute access to mapped memory
4852     // that was not previously executable.
4853     //
4854     // Instead, stick the executable region in anonymous memory.  Yuck.
4855     // Penalty is that ~4 pages will not be shareable - in the future
4856     // we might consider DLLizing the shared archive with a proper PE
4857     // header so that mapping executable + sharing is possible.
4858 
4859     base = (char*) VirtualAlloc(addr, bytes, MEM_COMMIT | MEM_RESERVE,
4860                                 PAGE_READWRITE);
4861     if (base == NULL) {
4862       log_info(os)("VirtualAlloc() failed: GetLastError->%ld.", GetLastError());
4863       CloseHandle(hFile);
4864       return NULL;
4865     }
4866 
4867     // Record virtual memory allocation
4868     MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
4869 
4870     DWORD bytes_read;
4871     OVERLAPPED overlapped;
4872     overlapped.Offset = (DWORD)file_offset;
4873     overlapped.OffsetHigh = 0;
4874     overlapped.hEvent = NULL;
4875     // ReadFile guarantees that if the return value is true, the requested
4876     // number of bytes were read before returning.
4877     bool res = ReadFile(hFile, base, (DWORD)bytes, &bytes_read, &overlapped) != 0;
4878     if (!res) {
4879       log_info(os)("ReadFile() failed: GetLastError->%ld.", GetLastError());
4880       release_memory(base, bytes);
4881       CloseHandle(hFile);
4882       return NULL;
4883     }
4884   } else {
4885     HANDLE hMap = CreateFileMapping(hFile, NULL, PAGE_WRITECOPY, 0, 0,
4886                                     NULL /* file_name */);
4887     if (hMap == NULL) {
4888       log_info(os)("CreateFileMapping() failed: GetLastError->%ld.", GetLastError());
4889       CloseHandle(hFile);
4890       return NULL;
4891     }
4892 
4893     DWORD access = read_only ? FILE_MAP_READ : FILE_MAP_COPY;
4894     base = (char*)MapViewOfFileEx(hMap, access, 0, (DWORD)file_offset,
4895                                   (DWORD)bytes, addr);
4896     if (base == NULL) {
4897       log_info(os)("MapViewOfFileEx() failed: GetLastError->%ld.", GetLastError());
4898       CloseHandle(hMap);
4899       CloseHandle(hFile);
4900       return NULL;
4901     }
4902 
4903     if (CloseHandle(hMap) == 0) {
4904       log_info(os)("CloseHandle(hMap) failed: GetLastError->%ld.", GetLastError());
4905       CloseHandle(hFile);
4906       return base;
4907     }
4908   }
4909 
4910   if (allow_exec) {
4911     DWORD old_protect;
4912     DWORD exec_access = read_only ? PAGE_EXECUTE_READ : PAGE_EXECUTE_READWRITE;
4913     bool res = VirtualProtect(base, bytes, exec_access, &old_protect) != 0;
4914 
4915     if (!res) {
4916       log_info(os)("VirtualProtect() failed: GetLastError->%ld.", GetLastError());
4917       // Don't consider this a hard error, on IA32 even if the
4918       // VirtualProtect fails, we should still be able to execute
4919       CloseHandle(hFile);
4920       return base;
4921     }
4922   }
4923 
4924   if (CloseHandle(hFile) == 0) {
4925     log_info(os)("CloseHandle(hFile) failed: GetLastError->%ld.", GetLastError());
4926     return base;
4927   }
4928 
4929   return base;
4930 }
4931 
4932 
4933 // Remap a block of memory.
4934 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
4935                           char *addr, size_t bytes, bool read_only,
4936                           bool allow_exec) {
4937   // This OS does not allow existing memory maps to be remapped so we
4938   // would have to unmap the memory before we remap it.
4939 
4940   // Because there is a small window between unmapping memory and mapping
4941   // it in again with different protections, CDS archives are mapped RW
4942   // on windows, so this function isn't called.
4943   ShouldNotReachHere();
4944   return NULL;
4945 }
4946 
4947 
4948 // Unmap a block of memory.
4949 // Returns true=success, otherwise false.
4950 
4951 bool os::pd_unmap_memory(char* addr, size_t bytes) {
4952   MEMORY_BASIC_INFORMATION mem_info;
4953   if (VirtualQuery(addr, &mem_info, sizeof(mem_info)) == 0) {
4954     log_info(os)("VirtualQuery() failed: GetLastError->%ld.", GetLastError());
4955     return false;
4956   }
4957 
4958   // Executable memory was not mapped using CreateFileMapping/MapViewOfFileEx.
4959   // Instead, executable region was allocated using VirtualAlloc(). See
4960   // pd_map_memory() above.
4961   //
4962   // The following flags should match the 'exec_access' flages used for
4963   // VirtualProtect() in pd_map_memory().
4964   if (mem_info.Protect == PAGE_EXECUTE_READ ||
4965       mem_info.Protect == PAGE_EXECUTE_READWRITE) {
4966     return pd_release_memory(addr, bytes);
4967   }
4968 
4969   BOOL result = UnmapViewOfFile(addr);
4970   if (result == 0) {
4971     log_info(os)("UnmapViewOfFile() failed: GetLastError->%ld.", GetLastError());
4972     return false;
4973   }
4974   return true;
4975 }
4976 
4977 void os::pause() {
4978   char filename[MAX_PATH];
4979   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4980     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4981   } else {
4982     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4983   }
4984 
4985   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4986   if (fd != -1) {
4987     struct stat buf;
4988     ::close(fd);
4989     while (::stat(filename, &buf) == 0) {
4990       Sleep(100);
4991     }
4992   } else {
4993     jio_fprintf(stderr,
4994                 "Could not open pause file '%s', continuing immediately.\n", filename);
4995   }
4996 }
4997 
4998 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
4999 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
5000 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
5001 
5002 os::ThreadCrashProtection::ThreadCrashProtection() {
5003 }
5004 
5005 // See the caveats for this class in os_windows.hpp
5006 // Protects the callback call so that raised OS EXCEPTIONS causes a jump back
5007 // into this method and returns false. If no OS EXCEPTION was raised, returns
5008 // true.
5009 // The callback is supposed to provide the method that should be protected.
5010 //
5011 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
5012 
5013   Thread::muxAcquire(&_crash_mux, "CrashProtection");
5014 
5015   _protected_thread = Thread::current_or_null();
5016   assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
5017 
5018   bool success = true;
5019   __try {
5020     _crash_protection = this;
5021     cb.call();
5022   } __except(EXCEPTION_EXECUTE_HANDLER) {
5023     // only for protection, nothing to do
5024     success = false;
5025   }
5026   _crash_protection = NULL;
5027   _protected_thread = NULL;
5028   Thread::muxRelease(&_crash_mux);
5029   return success;
5030 }
5031 
5032 
5033 class HighResolutionInterval : public CHeapObj<mtThread> {
5034   // The default timer resolution seems to be 10 milliseconds.
5035   // (Where is this written down?)
5036   // If someone wants to sleep for only a fraction of the default,
5037   // then we set the timer resolution down to 1 millisecond for
5038   // the duration of their interval.
5039   // We carefully set the resolution back, since otherwise we
5040   // seem to incur an overhead (3%?) that we don't need.
5041   // CONSIDER: if ms is small, say 3, then we should run with a high resolution time.
5042   // Buf if ms is large, say 500, or 503, we should avoid the call to timeBeginPeriod().
5043   // Alternatively, we could compute the relative error (503/500 = .6%) and only use
5044   // timeBeginPeriod() if the relative error exceeded some threshold.
5045   // timeBeginPeriod() has been linked to problems with clock drift on win32 systems and
5046   // to decreased efficiency related to increased timer "tick" rates.  We want to minimize
5047   // (a) calls to timeBeginPeriod() and timeEndPeriod() and (b) time spent with high
5048   // resolution timers running.
5049  private:
5050   jlong resolution;
5051  public:
5052   HighResolutionInterval(jlong ms) {
5053     resolution = ms % 10L;
5054     if (resolution != 0) {
5055       MMRESULT result = timeBeginPeriod(1L);
5056     }
5057   }
5058   ~HighResolutionInterval() {
5059     if (resolution != 0) {
5060       MMRESULT result = timeEndPeriod(1L);
5061     }
5062     resolution = 0L;
5063   }
5064 };
5065 
5066 // An Event wraps a win32 "CreateEvent" kernel handle.
5067 //
5068 // We have a number of choices regarding "CreateEvent" win32 handle leakage:
5069 //
5070 // 1:  When a thread dies return the Event to the EventFreeList, clear the ParkHandle
5071 //     field, and call CloseHandle() on the win32 event handle.  Unpark() would
5072 //     need to be modified to tolerate finding a NULL (invalid) win32 event handle.
5073 //     In addition, an unpark() operation might fetch the handle field, but the
5074 //     event could recycle between the fetch and the SetEvent() operation.
5075 //     SetEvent() would either fail because the handle was invalid, or inadvertently work,
5076 //     as the win32 handle value had been recycled.  In an ideal world calling SetEvent()
5077 //     on an stale but recycled handle would be harmless, but in practice this might
5078 //     confuse other non-Sun code, so it's not a viable approach.
5079 //
5080 // 2:  Once a win32 event handle is associated with an Event, it remains associated
5081 //     with the Event.  The event handle is never closed.  This could be construed
5082 //     as handle leakage, but only up to the maximum # of threads that have been extant
5083 //     at any one time.  This shouldn't be an issue, as windows platforms typically
5084 //     permit a process to have hundreds of thousands of open handles.
5085 //
5086 // 3:  Same as (1), but periodically, at stop-the-world time, rundown the EventFreeList
5087 //     and release unused handles.
5088 //
5089 // 4:  Add a CRITICAL_SECTION to the Event to protect LD+SetEvent from LD;ST(null);CloseHandle.
5090 //     It's not clear, however, that we wouldn't be trading one type of leak for another.
5091 //
5092 // 5.  Use an RCU-like mechanism (Read-Copy Update).
5093 //     Or perhaps something similar to Maged Michael's "Hazard pointers".
5094 //
5095 // We use (2).
5096 //
5097 // TODO-FIXME:
5098 // 1.  Reconcile Doug's JSR166 j.u.c park-unpark with the objectmonitor implementation.
5099 // 2.  Consider wrapping the WaitForSingleObject(Ex) calls in SEH try/finally blocks
5100 //     to recover from (or at least detect) the dreaded Windows 841176 bug.
5101 // 3.  Collapse the JSR166 parker event, and the objectmonitor ParkEvent
5102 //     into a single win32 CreateEvent() handle.
5103 //
5104 // Assumption:
5105 //    Only one parker can exist on an event, which is why we allocate
5106 //    them per-thread. Multiple unparkers can coexist.
5107 //
5108 // _Event transitions in park()
5109 //   -1 => -1 : illegal
5110 //    1 =>  0 : pass - return immediately
5111 //    0 => -1 : block; then set _Event to 0 before returning
5112 //
5113 // _Event transitions in unpark()
5114 //    0 => 1 : just return
5115 //    1 => 1 : just return
5116 //   -1 => either 0 or 1; must signal target thread
5117 //         That is, we can safely transition _Event from -1 to either
5118 //         0 or 1.
5119 //
5120 // _Event serves as a restricted-range semaphore.
5121 //   -1 : thread is blocked, i.e. there is a waiter
5122 //    0 : neutral: thread is running or ready,
5123 //        could have been signaled after a wait started
5124 //    1 : signaled - thread is running or ready
5125 //
5126 // Another possible encoding of _Event would be with
5127 // explicit "PARKED" == 01b and "SIGNALED" == 10b bits.
5128 //
5129 
5130 int os::PlatformEvent::park(jlong Millis) {
5131   // Transitions for _Event:
5132   //   -1 => -1 : illegal
5133   //    1 =>  0 : pass - return immediately
5134   //    0 => -1 : block; then set _Event to 0 before returning
5135 
5136   guarantee(_ParkHandle != NULL , "Invariant");
5137   guarantee(Millis > 0          , "Invariant");
5138 
5139   // CONSIDER: defer assigning a CreateEvent() handle to the Event until
5140   // the initial park() operation.
5141   // Consider: use atomic decrement instead of CAS-loop
5142 
5143   int v;
5144   for (;;) {
5145     v = _Event;
5146     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
5147   }
5148   guarantee((v == 0) || (v == 1), "invariant");
5149   if (v != 0) return OS_OK;
5150 
5151   // Do this the hard way by blocking ...
5152   // TODO: consider a brief spin here, gated on the success of recent
5153   // spin attempts by this thread.
5154   //
5155   // We decompose long timeouts into series of shorter timed waits.
5156   // Evidently large timo values passed in WaitForSingleObject() are problematic on some
5157   // versions of Windows.  See EventWait() for details.  This may be superstition.  Or not.
5158   // We trust the WAIT_TIMEOUT indication and don't track the elapsed wait time
5159   // with os::javaTimeNanos().  Furthermore, we assume that spurious returns from
5160   // ::WaitForSingleObject() caused by latent ::setEvent() operations will tend
5161   // to happen early in the wait interval.  Specifically, after a spurious wakeup (rv ==
5162   // WAIT_OBJECT_0 but _Event is still < 0) we don't bother to recompute Millis to compensate
5163   // for the already waited time.  This policy does not admit any new outcomes.
5164   // In the future, however, we might want to track the accumulated wait time and
5165   // adjust Millis accordingly if we encounter a spurious wakeup.
5166 
5167   const int MAXTIMEOUT = 0x10000000;
5168   DWORD rv = WAIT_TIMEOUT;
5169   while (_Event < 0 && Millis > 0) {
5170     DWORD prd = Millis;     // set prd = MAX (Millis, MAXTIMEOUT)
5171     if (Millis > MAXTIMEOUT) {
5172       prd = MAXTIMEOUT;
5173     }
5174     HighResolutionInterval *phri = NULL;
5175     if (!ForceTimeHighResolution) {
5176       phri = new HighResolutionInterval(prd);
5177     }
5178     rv = ::WaitForSingleObject(_ParkHandle, prd);
5179     assert(rv == WAIT_OBJECT_0 || rv == WAIT_TIMEOUT, "WaitForSingleObject failed");
5180     if (rv == WAIT_TIMEOUT) {
5181       Millis -= prd;
5182     }
5183     delete phri; // if it is NULL, harmless
5184   }
5185   v = _Event;
5186   _Event = 0;
5187   // see comment at end of os::PlatformEvent::park() below:
5188   OrderAccess::fence();
5189   // If we encounter a nearly simultanous timeout expiry and unpark()
5190   // we return OS_OK indicating we awoke via unpark().
5191   // Implementor's license -- returning OS_TIMEOUT would be equally valid, however.
5192   return (v >= 0) ? OS_OK : OS_TIMEOUT;
5193 }
5194 
5195 void os::PlatformEvent::park() {
5196   // Transitions for _Event:
5197   //   -1 => -1 : illegal
5198   //    1 =>  0 : pass - return immediately
5199   //    0 => -1 : block; then set _Event to 0 before returning
5200 
5201   guarantee(_ParkHandle != NULL, "Invariant");
5202   // Invariant: Only the thread associated with the Event/PlatformEvent
5203   // may call park().
5204   // Consider: use atomic decrement instead of CAS-loop
5205   int v;
5206   for (;;) {
5207     v = _Event;
5208     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
5209   }
5210   guarantee((v == 0) || (v == 1), "invariant");
5211   if (v != 0) return;
5212 
5213   // Do this the hard way by blocking ...
5214   // TODO: consider a brief spin here, gated on the success of recent
5215   // spin attempts by this thread.
5216   while (_Event < 0) {
5217     DWORD rv = ::WaitForSingleObject(_ParkHandle, INFINITE);
5218     assert(rv == WAIT_OBJECT_0, "WaitForSingleObject failed");
5219   }
5220 
5221   // Usually we'll find _Event == 0 at this point, but as
5222   // an optional optimization we clear it, just in case can
5223   // multiple unpark() operations drove _Event up to 1.
5224   _Event = 0;
5225   OrderAccess::fence();
5226   guarantee(_Event >= 0, "invariant");
5227 }
5228 
5229 void os::PlatformEvent::unpark() {
5230   guarantee(_ParkHandle != NULL, "Invariant");
5231 
5232   // Transitions for _Event:
5233   //    0 => 1 : just return
5234   //    1 => 1 : just return
5235   //   -1 => either 0 or 1; must signal target thread
5236   //         That is, we can safely transition _Event from -1 to either
5237   //         0 or 1.
5238   // See also: "Semaphores in Plan 9" by Mullender & Cox
5239   //
5240   // Note: Forcing a transition from "-1" to "1" on an unpark() means
5241   // that it will take two back-to-back park() calls for the owning
5242   // thread to block. This has the benefit of forcing a spurious return
5243   // from the first park() call after an unpark() call which will help
5244   // shake out uses of park() and unpark() without condition variables.
5245 
5246   if (Atomic::xchg(1, &_Event) >= 0) return;
5247 
5248   ::SetEvent(_ParkHandle);
5249 }
5250 
5251 
5252 // JSR166
5253 // -------------------------------------------------------
5254 
5255 // The Windows implementation of Park is very straightforward: Basic
5256 // operations on Win32 Events turn out to have the right semantics to
5257 // use them directly. We opportunistically resuse the event inherited
5258 // from Monitor.
5259 
5260 void Parker::park(bool isAbsolute, jlong time) {
5261   guarantee(_ParkEvent != NULL, "invariant");
5262   // First, demultiplex/decode time arguments
5263   if (time < 0) { // don't wait
5264     return;
5265   } else if (time == 0 && !isAbsolute) {
5266     time = INFINITE;
5267   } else if (isAbsolute) {
5268     time -= os::javaTimeMillis(); // convert to relative time
5269     if (time <= 0) {  // already elapsed
5270       return;
5271     }
5272   } else { // relative
5273     time /= 1000000;  // Must coarsen from nanos to millis
5274     if (time == 0) {  // Wait for the minimal time unit if zero
5275       time = 1;
5276     }
5277   }
5278 
5279   JavaThread* thread = JavaThread::current();
5280 
5281   // Don't wait if interrupted or already triggered
5282   if (thread->is_interrupted(false) ||
5283       WaitForSingleObject(_ParkEvent, 0) == WAIT_OBJECT_0) {
5284     ResetEvent(_ParkEvent);
5285     return;
5286   } else {
5287     ThreadBlockInVM tbivm(thread);
5288     OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
5289     thread->set_suspend_equivalent();
5290 
5291     WaitForSingleObject(_ParkEvent, time);
5292     ResetEvent(_ParkEvent);
5293 
5294     // If externally suspended while waiting, re-suspend
5295     if (thread->handle_special_suspend_equivalent_condition()) {
5296       thread->java_suspend_self();
5297     }
5298   }
5299 }
5300 
5301 void Parker::unpark() {
5302   guarantee(_ParkEvent != NULL, "invariant");
5303   SetEvent(_ParkEvent);
5304 }
5305 
5306 // Platform Monitor implementation
5307 
5308 // Must already be locked
5309 int os::PlatformMonitor::wait(jlong millis) {
5310   assert(millis >= 0, "negative timeout");
5311   int ret = OS_TIMEOUT;
5312   int status = SleepConditionVariableCS(&_cond, &_mutex,
5313                                         millis == 0 ? INFINITE : millis);
5314   if (status != 0) {
5315     ret = OS_OK;
5316   }
5317   #ifndef PRODUCT
5318   else {
5319     DWORD err = GetLastError();
5320     assert(err == ERROR_TIMEOUT, "SleepConditionVariableCS: %ld:", err);
5321   }
5322   #endif
5323   return ret;
5324 }
5325 
5326 // Run the specified command in a separate process. Return its exit value,
5327 // or -1 on failure (e.g. can't create a new process).
5328 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
5329   STARTUPINFO si;
5330   PROCESS_INFORMATION pi;
5331   DWORD exit_code;
5332 
5333   char * cmd_string;
5334   const char * cmd_prefix = "cmd /C ";
5335   size_t len = strlen(cmd) + strlen(cmd_prefix) + 1;
5336   cmd_string = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtInternal);
5337   if (cmd_string == NULL) {
5338     return -1;
5339   }
5340   cmd_string[0] = '\0';
5341   strcat(cmd_string, cmd_prefix);
5342   strcat(cmd_string, cmd);
5343 
5344   // now replace all '\n' with '&'
5345   char * substring = cmd_string;
5346   while ((substring = strchr(substring, '\n')) != NULL) {
5347     substring[0] = '&';
5348     substring++;
5349   }
5350   memset(&si, 0, sizeof(si));
5351   si.cb = sizeof(si);
5352   memset(&pi, 0, sizeof(pi));
5353   BOOL rslt = CreateProcess(NULL,   // executable name - use command line
5354                             cmd_string,    // command line
5355                             NULL,   // process security attribute
5356                             NULL,   // thread security attribute
5357                             TRUE,   // inherits system handles
5358                             0,      // no creation flags
5359                             NULL,   // use parent's environment block
5360                             NULL,   // use parent's starting directory
5361                             &si,    // (in) startup information
5362                             &pi);   // (out) process information
5363 
5364   if (rslt) {
5365     // Wait until child process exits.
5366     WaitForSingleObject(pi.hProcess, INFINITE);
5367 
5368     GetExitCodeProcess(pi.hProcess, &exit_code);
5369 
5370     // Close process and thread handles.
5371     CloseHandle(pi.hProcess);
5372     CloseHandle(pi.hThread);
5373   } else {
5374     exit_code = -1;
5375   }
5376 
5377   FREE_C_HEAP_ARRAY(char, cmd_string);
5378   return (int)exit_code;
5379 }
5380 
5381 bool os::find(address addr, outputStream* st) {
5382   int offset = -1;
5383   bool result = false;
5384   char buf[256];
5385   if (os::dll_address_to_library_name(addr, buf, sizeof(buf), &offset)) {
5386     st->print(PTR_FORMAT " ", addr);
5387     if (strlen(buf) < sizeof(buf) - 1) {
5388       char* p = strrchr(buf, '\\');
5389       if (p) {
5390         st->print("%s", p + 1);
5391       } else {
5392         st->print("%s", buf);
5393       }
5394     } else {
5395         // The library name is probably truncated. Let's omit the library name.
5396         // See also JDK-8147512.
5397     }
5398     if (os::dll_address_to_function_name(addr, buf, sizeof(buf), &offset)) {
5399       st->print("::%s + 0x%x", buf, offset);
5400     }
5401     st->cr();
5402     result = true;
5403   }
5404   return result;
5405 }
5406 
5407 static jint initSock() {
5408   WSADATA wsadata;
5409 
5410   if (WSAStartup(MAKEWORD(2,2), &wsadata) != 0) {
5411     jio_fprintf(stderr, "Could not initialize Winsock (error: %d)\n",
5412                 ::GetLastError());
5413     return JNI_ERR;
5414   }
5415   return JNI_OK;
5416 }
5417 
5418 struct hostent* os::get_host_by_name(char* name) {
5419   return (struct hostent*)gethostbyname(name);
5420 }
5421 
5422 int os::socket_close(int fd) {
5423   return ::closesocket(fd);
5424 }
5425 
5426 int os::socket(int domain, int type, int protocol) {
5427   return ::socket(domain, type, protocol);
5428 }
5429 
5430 int os::connect(int fd, struct sockaddr* him, socklen_t len) {
5431   return ::connect(fd, him, len);
5432 }
5433 
5434 int os::recv(int fd, char* buf, size_t nBytes, uint flags) {
5435   return ::recv(fd, buf, (int)nBytes, flags);
5436 }
5437 
5438 int os::send(int fd, char* buf, size_t nBytes, uint flags) {
5439   return ::send(fd, buf, (int)nBytes, flags);
5440 }
5441 
5442 int os::raw_send(int fd, char* buf, size_t nBytes, uint flags) {
5443   return ::send(fd, buf, (int)nBytes, flags);
5444 }
5445 
5446 // WINDOWS CONTEXT Flags for THREAD_SAMPLING
5447 #if defined(IA32)
5448   #define sampling_context_flags (CONTEXT_FULL | CONTEXT_FLOATING_POINT | CONTEXT_EXTENDED_REGISTERS)
5449 #elif defined (AMD64)
5450   #define sampling_context_flags (CONTEXT_FULL | CONTEXT_FLOATING_POINT)
5451 #endif
5452 
5453 // returns true if thread could be suspended,
5454 // false otherwise
5455 static bool do_suspend(HANDLE* h) {
5456   if (h != NULL) {
5457     if (SuspendThread(*h) != ~0) {
5458       return true;
5459     }
5460   }
5461   return false;
5462 }
5463 
5464 // resume the thread
5465 // calling resume on an active thread is a no-op
5466 static void do_resume(HANDLE* h) {
5467   if (h != NULL) {
5468     ResumeThread(*h);
5469   }
5470 }
5471 
5472 // retrieve a suspend/resume context capable handle
5473 // from the tid. Caller validates handle return value.
5474 void get_thread_handle_for_extended_context(HANDLE* h,
5475                                             OSThread::thread_id_t tid) {
5476   if (h != NULL) {
5477     *h = OpenThread(THREAD_SUSPEND_RESUME | THREAD_GET_CONTEXT | THREAD_QUERY_INFORMATION, FALSE, tid);
5478   }
5479 }
5480 
5481 // Thread sampling implementation
5482 //
5483 void os::SuspendedThreadTask::internal_do_task() {
5484   CONTEXT    ctxt;
5485   HANDLE     h = NULL;
5486 
5487   // get context capable handle for thread
5488   get_thread_handle_for_extended_context(&h, _thread->osthread()->thread_id());
5489 
5490   // sanity
5491   if (h == NULL || h == INVALID_HANDLE_VALUE) {
5492     return;
5493   }
5494 
5495   // suspend the thread
5496   if (do_suspend(&h)) {
5497     ctxt.ContextFlags = sampling_context_flags;
5498     // get thread context
5499     GetThreadContext(h, &ctxt);
5500     SuspendedThreadTaskContext context(_thread, &ctxt);
5501     // pass context to Thread Sampling impl
5502     do_task(context);
5503     // resume thread
5504     do_resume(&h);
5505   }
5506 
5507   // close handle
5508   CloseHandle(h);
5509 }
5510 
5511 bool os::start_debugging(char *buf, int buflen) {
5512   int len = (int)strlen(buf);
5513   char *p = &buf[len];
5514 
5515   jio_snprintf(p, buflen-len,
5516              "\n\n"
5517              "Do you want to debug the problem?\n\n"
5518              "To debug, attach Visual Studio to process %d; then switch to thread 0x%x\n"
5519              "Select 'Yes' to launch Visual Studio automatically (PATH must include msdev)\n"
5520              "Otherwise, select 'No' to abort...",
5521              os::current_process_id(), os::current_thread_id());
5522 
5523   bool yes = os::message_box("Unexpected Error", buf);
5524 
5525   if (yes) {
5526     // os::breakpoint() calls DebugBreak(), which causes a breakpoint
5527     // exception. If VM is running inside a debugger, the debugger will
5528     // catch the exception. Otherwise, the breakpoint exception will reach
5529     // the default windows exception handler, which can spawn a debugger and
5530     // automatically attach to the dying VM.
5531     os::breakpoint();
5532     yes = false;
5533   }
5534   return yes;
5535 }
5536 
5537 void* os::get_default_process_handle() {
5538   return (void*)GetModuleHandle(NULL);
5539 }
5540 
5541 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
5542 // which is used to find statically linked in agents.
5543 // Additionally for windows, takes into account __stdcall names.
5544 // Parameters:
5545 //            sym_name: Symbol in library we are looking for
5546 //            lib_name: Name of library to look in, NULL for shared libs.
5547 //            is_absolute_path == true if lib_name is absolute path to agent
5548 //                                     such as "C:/a/b/L.dll"
5549 //            == false if only the base name of the library is passed in
5550 //               such as "L"
5551 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
5552                                     bool is_absolute_path) {
5553   char *agent_entry_name;
5554   size_t len;
5555   size_t name_len;
5556   size_t prefix_len = strlen(JNI_LIB_PREFIX);
5557   size_t suffix_len = strlen(JNI_LIB_SUFFIX);
5558   const char *start;
5559 
5560   if (lib_name != NULL) {
5561     len = name_len = strlen(lib_name);
5562     if (is_absolute_path) {
5563       // Need to strip path, prefix and suffix
5564       if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
5565         lib_name = ++start;
5566       } else {
5567         // Need to check for drive prefix
5568         if ((start = strchr(lib_name, ':')) != NULL) {
5569           lib_name = ++start;
5570         }
5571       }
5572       if (len <= (prefix_len + suffix_len)) {
5573         return NULL;
5574       }
5575       lib_name += prefix_len;
5576       name_len = strlen(lib_name) - suffix_len;
5577     }
5578   }
5579   len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
5580   agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
5581   if (agent_entry_name == NULL) {
5582     return NULL;
5583   }
5584   if (lib_name != NULL) {
5585     const char *p = strrchr(sym_name, '@');
5586     if (p != NULL && p != sym_name) {
5587       // sym_name == _Agent_OnLoad@XX
5588       strncpy(agent_entry_name, sym_name, (p - sym_name));
5589       agent_entry_name[(p-sym_name)] = '\0';
5590       // agent_entry_name == _Agent_OnLoad
5591       strcat(agent_entry_name, "_");
5592       strncat(agent_entry_name, lib_name, name_len);
5593       strcat(agent_entry_name, p);
5594       // agent_entry_name == _Agent_OnLoad_lib_name@XX
5595     } else {
5596       strcpy(agent_entry_name, sym_name);
5597       strcat(agent_entry_name, "_");
5598       strncat(agent_entry_name, lib_name, name_len);
5599     }
5600   } else {
5601     strcpy(agent_entry_name, sym_name);
5602   }
5603   return agent_entry_name;
5604 }
5605 
5606 #ifndef PRODUCT
5607 
5608 // test the code path in reserve_memory_special() that tries to allocate memory in a single
5609 // contiguous memory block at a particular address.
5610 // The test first tries to find a good approximate address to allocate at by using the same
5611 // method to allocate some memory at any address. The test then tries to allocate memory in
5612 // the vicinity (not directly after it to avoid possible by-chance use of that location)
5613 // This is of course only some dodgy assumption, there is no guarantee that the vicinity of
5614 // the previously allocated memory is available for allocation. The only actual failure
5615 // that is reported is when the test tries to allocate at a particular location but gets a
5616 // different valid one. A NULL return value at this point is not considered an error but may
5617 // be legitimate.
5618 void TestReserveMemorySpecial_test() {
5619   if (!UseLargePages) {
5620     return;
5621   }
5622   // save current value of globals
5623   bool old_use_large_pages_individual_allocation = UseLargePagesIndividualAllocation;
5624   bool old_use_numa_interleaving = UseNUMAInterleaving;
5625 
5626   // set globals to make sure we hit the correct code path
5627   UseLargePagesIndividualAllocation = UseNUMAInterleaving = false;
5628 
5629   // do an allocation at an address selected by the OS to get a good one.
5630   const size_t large_allocation_size = os::large_page_size() * 4;
5631   char* result = os::reserve_memory_special(large_allocation_size, os::large_page_size(), NULL, false);
5632   if (result == NULL) {
5633   } else {
5634     os::release_memory_special(result, large_allocation_size);
5635 
5636     // allocate another page within the recently allocated memory area which seems to be a good location. At least
5637     // we managed to get it once.
5638     const size_t expected_allocation_size = os::large_page_size();
5639     char* expected_location = result + os::large_page_size();
5640     char* actual_location = os::reserve_memory_special(expected_allocation_size, os::large_page_size(), expected_location, false);
5641     if (actual_location == NULL) {
5642     } else {
5643       // release memory
5644       os::release_memory_special(actual_location, expected_allocation_size);
5645       // only now check, after releasing any memory to avoid any leaks.
5646       assert(actual_location == expected_location,
5647              "Failed to allocate memory at requested location " PTR_FORMAT " of size " SIZE_FORMAT ", is " PTR_FORMAT " instead",
5648              expected_location, expected_allocation_size, actual_location);
5649     }
5650   }
5651 
5652   // restore globals
5653   UseLargePagesIndividualAllocation = old_use_large_pages_individual_allocation;
5654   UseNUMAInterleaving = old_use_numa_interleaving;
5655 }
5656 #endif // PRODUCT
5657 
5658 /*
5659   All the defined signal names for Windows.
5660 
5661   NOTE that not all of these names are accepted by FindSignal!
5662 
5663   For various reasons some of these may be rejected at runtime.
5664 
5665   Here are the names currently accepted by a user of sun.misc.Signal with
5666   1.4.1 (ignoring potential interaction with use of chaining, etc):
5667 
5668      (LIST TBD)
5669 
5670 */
5671 int os::get_signal_number(const char* name) {
5672   static const struct {
5673     const char* name;
5674     int         number;
5675   } siglabels [] =
5676     // derived from version 6.0 VC98/include/signal.h
5677   {"ABRT",      SIGABRT,        // abnormal termination triggered by abort cl
5678   "FPE",        SIGFPE,         // floating point exception
5679   "SEGV",       SIGSEGV,        // segment violation
5680   "INT",        SIGINT,         // interrupt
5681   "TERM",       SIGTERM,        // software term signal from kill
5682   "BREAK",      SIGBREAK,       // Ctrl-Break sequence
5683   "ILL",        SIGILL};        // illegal instruction
5684   for (unsigned i = 0; i < ARRAY_SIZE(siglabels); ++i) {
5685     if (strcmp(name, siglabels[i].name) == 0) {
5686       return siglabels[i].number;
5687     }
5688   }
5689   return -1;
5690 }
5691 
5692 // Fast current thread access
5693 
5694 int os::win32::_thread_ptr_offset = 0;
5695 
5696 static void call_wrapper_dummy() {}
5697 
5698 // We need to call the os_exception_wrapper once so that it sets
5699 // up the offset from FS of the thread pointer.
5700 void os::win32::initialize_thread_ptr_offset() {
5701   os::os_exception_wrapper((java_call_t)call_wrapper_dummy,
5702                            NULL, NULL, NULL, NULL);
5703 }
5704 
5705 bool os::supports_map_sync() {
5706   return false;
5707 }