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