1 /*
   2  * Copyright (c) 1997, 2017, 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 "classfile/classLoader.hpp"
  30 #include "classfile/systemDictionary.hpp"
  31 #include "classfile/vmSymbols.hpp"
  32 #include "code/icBuffer.hpp"
  33 #include "code/vtableStubs.hpp"
  34 #include "compiler/compileBroker.hpp"
  35 #include "compiler/disassembler.hpp"
  36 #include "interpreter/interpreter.hpp"
  37 #include "jvm_windows.h"
  38 #include "logging/log.hpp"
  39 #include "memory/allocation.inline.hpp"
  40 #include "memory/filemap.hpp"
  41 #include "oops/oop.inline.hpp"
  42 #include "os_share_windows.hpp"
  43 #include "os_windows.inline.hpp"
  44 #include "prims/jniFastGetField.hpp"
  45 #include "prims/jvm.h"
  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.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.inline.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 "semaphore_windows.hpp"
  67 #include "services/attachListener.hpp"
  68 #include "services/memTracker.hpp"
  69 #include "services/runtimeService.hpp"
  70 #include "utilities/align.hpp"
  71 #include "utilities/decoder.hpp"
  72 #include "utilities/defaultStream.hpp"
  73 #include "utilities/events.hpp"
  74 #include "utilities/growableArray.hpp"
  75 #include "utilities/macros.hpp"
  76 #include "utilities/vmError.hpp"
  77 #include "symbolengine.hpp"
  78 #include "windbghelp.hpp"
  79 
  80 
  81 #ifdef _DEBUG
  82 #include <crtdbg.h>
  83 #endif
  84 
  85 
  86 #include <windows.h>
  87 #include <sys/types.h>
  88 #include <sys/stat.h>
  89 #include <sys/timeb.h>
  90 #include <objidl.h>
  91 #include <shlobj.h>
  92 
  93 #include <malloc.h>
  94 #include <signal.h>
  95 #include <direct.h>
  96 #include <errno.h>
  97 #include <fcntl.h>
  98 #include <io.h>
  99 #include <process.h>              // For _beginthreadex(), _endthreadex()
 100 #include <imagehlp.h>             // For os::dll_address_to_function_name
 101 // for enumerating dll libraries
 102 #include <vdmdbg.h>
 103 
 104 // for timer info max values which include all bits
 105 #define ALL_64_BITS CONST64(-1)
 106 
 107 // For DLL loading/load error detection
 108 // Values of PE COFF
 109 #define IMAGE_FILE_PTR_TO_SIGNATURE 0x3c
 110 #define IMAGE_FILE_SIGNATURE_LENGTH 4
 111 
 112 static HANDLE main_process;
 113 static HANDLE main_thread;
 114 static int    main_thread_id;
 115 
 116 static FILETIME process_creation_time;
 117 static FILETIME process_exit_time;
 118 static FILETIME process_user_time;
 119 static FILETIME process_kernel_time;
 120 
 121 #ifdef _M_AMD64
 122   #define __CPU__ amd64
 123 #else
 124   #define __CPU__ i486
 125 #endif
 126 
 127 // save DLL module handle, used by GetModuleFileName
 128 
 129 HINSTANCE vm_lib_handle;
 130 
 131 BOOL WINAPI DllMain(HINSTANCE hinst, DWORD reason, LPVOID reserved) {
 132   switch (reason) {
 133   case DLL_PROCESS_ATTACH:
 134     vm_lib_handle = hinst;
 135     if (ForceTimeHighResolution) {
 136       timeBeginPeriod(1L);
 137     }
 138     WindowsDbgHelp::pre_initialize();
 139     SymbolEngine::pre_initialize();
 140     break;
 141   case DLL_PROCESS_DETACH:
 142     if (ForceTimeHighResolution) {
 143       timeEndPeriod(1L);
 144     }
 145     break;
 146   default:
 147     break;
 148   }
 149   return true;
 150 }
 151 
 152 static inline double fileTimeAsDouble(FILETIME* time) {
 153   const double high  = (double) ((unsigned int) ~0);
 154   const double split = 10000000.0;
 155   double result = (time->dwLowDateTime / split) +
 156                    time->dwHighDateTime * (high/split);
 157   return result;
 158 }
 159 
 160 // Implementation of os
 161 
 162 bool os::unsetenv(const char* name) {
 163   assert(name != NULL, "Null pointer");
 164   return (SetEnvironmentVariable(name, NULL) == TRUE);
 165 }
 166 
 167 // No setuid programs under Windows.
 168 bool os::have_special_privileges() {
 169   return false;
 170 }
 171 
 172 
 173 // This method is  a periodic task to check for misbehaving JNI applications
 174 // under CheckJNI, we can add any periodic checks here.
 175 // For Windows at the moment does nothing
 176 void os::run_periodic_checks() {
 177   return;
 178 }
 179 
 180 // previous UnhandledExceptionFilter, if there is one
 181 static LPTOP_LEVEL_EXCEPTION_FILTER prev_uef_handler = NULL;
 182 
 183 LONG WINAPI Handle_FLT_Exception(struct _EXCEPTION_POINTERS* exceptionInfo);
 184 
 185 void os::init_system_properties_values() {
 186   // sysclasspath, java_home, dll_dir
 187   {
 188     char *home_path;
 189     char *dll_path;
 190     char *pslash;
 191     char *bin = "\\bin";
 192     char home_dir[MAX_PATH + 1];
 193     char *alt_home_dir = ::getenv("_ALT_JAVA_HOME_DIR");
 194 
 195     if (alt_home_dir != NULL)  {
 196       strncpy(home_dir, alt_home_dir, MAX_PATH + 1);
 197       home_dir[MAX_PATH] = '\0';
 198     } else {
 199       os::jvm_path(home_dir, sizeof(home_dir));
 200       // Found the full path to jvm.dll.
 201       // Now cut the path to <java_home>/jre if we can.
 202       *(strrchr(home_dir, '\\')) = '\0';  // get rid of \jvm.dll
 203       pslash = strrchr(home_dir, '\\');
 204       if (pslash != NULL) {
 205         *pslash = '\0';                   // get rid of \{client|server}
 206         pslash = strrchr(home_dir, '\\');
 207         if (pslash != NULL) {
 208           *pslash = '\0';                 // get rid of \bin
 209         }
 210       }
 211     }
 212 
 213     home_path = NEW_C_HEAP_ARRAY(char, strlen(home_dir) + 1, mtInternal);
 214     if (home_path == NULL) {
 215       return;
 216     }
 217     strcpy(home_path, home_dir);
 218     Arguments::set_java_home(home_path);
 219     FREE_C_HEAP_ARRAY(char, home_path);
 220 
 221     dll_path = NEW_C_HEAP_ARRAY(char, strlen(home_dir) + strlen(bin) + 1,
 222                                 mtInternal);
 223     if (dll_path == NULL) {
 224       return;
 225     }
 226     strcpy(dll_path, home_dir);
 227     strcat(dll_path, bin);
 228     Arguments::set_dll_dir(dll_path);
 229     FREE_C_HEAP_ARRAY(char, dll_path);
 230 
 231     if (!set_boot_path('\\', ';')) {
 232       return;
 233     }
 234   }
 235 
 236 // library_path
 237 #define EXT_DIR "\\lib\\ext"
 238 #define BIN_DIR "\\bin"
 239 #define PACKAGE_DIR "\\Sun\\Java"
 240   {
 241     // Win32 library search order (See the documentation for LoadLibrary):
 242     //
 243     // 1. The directory from which application is loaded.
 244     // 2. The system wide Java Extensions directory (Java only)
 245     // 3. System directory (GetSystemDirectory)
 246     // 4. Windows directory (GetWindowsDirectory)
 247     // 5. The PATH environment variable
 248     // 6. The current directory
 249 
 250     char *library_path;
 251     char tmp[MAX_PATH];
 252     char *path_str = ::getenv("PATH");
 253 
 254     library_path = NEW_C_HEAP_ARRAY(char, MAX_PATH * 5 + sizeof(PACKAGE_DIR) +
 255                                     sizeof(BIN_DIR) + (path_str ? strlen(path_str) : 0) + 10, mtInternal);
 256 
 257     library_path[0] = '\0';
 258 
 259     GetModuleFileName(NULL, tmp, sizeof(tmp));
 260     *(strrchr(tmp, '\\')) = '\0';
 261     strcat(library_path, tmp);
 262 
 263     GetWindowsDirectory(tmp, sizeof(tmp));
 264     strcat(library_path, ";");
 265     strcat(library_path, tmp);
 266     strcat(library_path, PACKAGE_DIR BIN_DIR);
 267 
 268     GetSystemDirectory(tmp, sizeof(tmp));
 269     strcat(library_path, ";");
 270     strcat(library_path, tmp);
 271 
 272     GetWindowsDirectory(tmp, sizeof(tmp));
 273     strcat(library_path, ";");
 274     strcat(library_path, tmp);
 275 
 276     if (path_str) {
 277       strcat(library_path, ";");
 278       strcat(library_path, path_str);
 279     }
 280 
 281     strcat(library_path, ";.");
 282 
 283     Arguments::set_library_path(library_path);
 284     FREE_C_HEAP_ARRAY(char, library_path);
 285   }
 286 
 287   // Default extensions directory
 288   {
 289     char path[MAX_PATH];
 290     char buf[2 * MAX_PATH + 2 * sizeof(EXT_DIR) + sizeof(PACKAGE_DIR) + 1];
 291     GetWindowsDirectory(path, MAX_PATH);
 292     sprintf(buf, "%s%s;%s%s%s", Arguments::get_java_home(), EXT_DIR,
 293             path, PACKAGE_DIR, EXT_DIR);
 294     Arguments::set_ext_dirs(buf);
 295   }
 296   #undef EXT_DIR
 297   #undef BIN_DIR
 298   #undef PACKAGE_DIR
 299 
 300 #ifndef _WIN64
 301   // set our UnhandledExceptionFilter and save any previous one
 302   prev_uef_handler = SetUnhandledExceptionFilter(Handle_FLT_Exception);
 303 #endif
 304 
 305   // Done
 306   return;
 307 }
 308 
 309 void os::breakpoint() {
 310   DebugBreak();
 311 }
 312 
 313 // Invoked from the BREAKPOINT Macro
 314 extern "C" void breakpoint() {
 315   os::breakpoint();
 316 }
 317 
 318 // RtlCaptureStackBackTrace Windows API may not exist prior to Windows XP.
 319 // So far, this method is only used by Native Memory Tracking, which is
 320 // only supported on Windows XP or later.
 321 //
 322 int os::get_native_stack(address* stack, int frames, int toSkip) {
 323   int captured = RtlCaptureStackBackTrace(toSkip + 1, frames, (PVOID*)stack, NULL);
 324   for (int index = captured; index < frames; index ++) {
 325     stack[index] = NULL;
 326   }
 327   return captured;
 328 }
 329 
 330 
 331 // os::current_stack_base()
 332 //
 333 //   Returns the base of the stack, which is the stack's
 334 //   starting address.  This function must be called
 335 //   while running on the stack of the thread being queried.
 336 
 337 address os::current_stack_base() {
 338   MEMORY_BASIC_INFORMATION minfo;
 339   address stack_bottom;
 340   size_t stack_size;
 341 
 342   VirtualQuery(&minfo, &minfo, sizeof(minfo));
 343   stack_bottom =  (address)minfo.AllocationBase;
 344   stack_size = minfo.RegionSize;
 345 
 346   // Add up the sizes of all the regions with the same
 347   // AllocationBase.
 348   while (1) {
 349     VirtualQuery(stack_bottom+stack_size, &minfo, sizeof(minfo));
 350     if (stack_bottom == (address)minfo.AllocationBase) {
 351       stack_size += minfo.RegionSize;
 352     } else {
 353       break;
 354     }
 355   }
 356   return stack_bottom + stack_size;
 357 }
 358 
 359 size_t os::current_stack_size() {
 360   size_t sz;
 361   MEMORY_BASIC_INFORMATION minfo;
 362   VirtualQuery(&minfo, &minfo, sizeof(minfo));
 363   sz = (size_t)os::current_stack_base() - (size_t)minfo.AllocationBase;
 364   return sz;
 365 }
 366 
 367 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
 368   const struct tm* time_struct_ptr = localtime(clock);
 369   if (time_struct_ptr != NULL) {
 370     *res = *time_struct_ptr;
 371     return res;
 372   }
 373   return NULL;
 374 }
 375 
 376 struct tm* os::gmtime_pd(const time_t* clock, struct tm* res) {
 377   const struct tm* time_struct_ptr = gmtime(clock);
 378   if (time_struct_ptr != NULL) {
 379     *res = *time_struct_ptr;
 380     return res;
 381   }
 382   return NULL;
 383 }
 384 
 385 LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo);
 386 
 387 // Thread start routine for all newly created threads
 388 static unsigned __stdcall thread_native_entry(Thread* thread) {
 389   // Try to randomize the cache line index of hot stack frames.
 390   // This helps when threads of the same stack traces evict each other's
 391   // cache lines. The threads can be either from the same JVM instance, or
 392   // from different JVM instances. The benefit is especially true for
 393   // processors with hyperthreading technology.
 394   static int counter = 0;
 395   int pid = os::current_process_id();
 396   _alloca(((pid ^ counter++) & 7) * 128);
 397 
 398   thread->initialize_thread_current();
 399 
 400   OSThread* osthr = thread->osthread();
 401   assert(osthr->get_state() == RUNNABLE, "invalid os thread state");
 402 
 403   if (UseNUMA) {
 404     int lgrp_id = os::numa_get_group_id();
 405     if (lgrp_id != -1) {
 406       thread->set_lgrp_id(lgrp_id);
 407     }
 408   }
 409 
 410   // Diagnostic code to investigate JDK-6573254
 411   int res = 30115;  // non-java thread
 412   if (thread->is_Java_thread()) {
 413     res = 20115;    // java thread
 414   }
 415 
 416   log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ").", os::current_thread_id());
 417 
 418   // Install a win32 structured exception handler around every thread created
 419   // by VM, so VM can generate error dump when an exception occurred in non-
 420   // Java thread (e.g. VM thread).
 421   __try {
 422     thread->run();
 423   } __except(topLevelExceptionFilter(
 424                                      (_EXCEPTION_POINTERS*)_exception_info())) {
 425     // Nothing to do.
 426   }
 427 
 428   log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ").", os::current_thread_id());
 429 
 430   // One less thread is executing
 431   // When the VMThread gets here, the main thread may have already exited
 432   // which frees the CodeHeap containing the Atomic::add code
 433   if (thread != VMThread::vm_thread() && VMThread::vm_thread() != NULL) {
 434     Atomic::dec_ptr((intptr_t*)&os::win32::_os_thread_count);
 435   }
 436 
 437   // If a thread has not deleted itself ("delete this") as part of its
 438   // termination sequence, we have to ensure thread-local-storage is
 439   // cleared before we actually terminate. No threads should ever be
 440   // deleted asynchronously with respect to their termination.
 441   if (Thread::current_or_null_safe() != NULL) {
 442     assert(Thread::current_or_null_safe() == thread, "current thread is wrong");
 443     thread->clear_thread_current();
 444   }
 445 
 446   // Thread must not return from exit_process_or_thread(), but if it does,
 447   // let it proceed to exit normally
 448   return (unsigned)os::win32::exit_process_or_thread(os::win32::EPT_THREAD, res);
 449 }
 450 
 451 static OSThread* create_os_thread(Thread* thread, HANDLE thread_handle,
 452                                   int thread_id) {
 453   // Allocate the OSThread object
 454   OSThread* osthread = new OSThread(NULL, NULL);
 455   if (osthread == NULL) return NULL;
 456 
 457   // Initialize support for Java interrupts
 458   HANDLE interrupt_event = CreateEvent(NULL, true, false, NULL);
 459   if (interrupt_event == NULL) {
 460     delete osthread;
 461     return NULL;
 462   }
 463   osthread->set_interrupt_event(interrupt_event);
 464 
 465   // Store info on the Win32 thread into the OSThread
 466   osthread->set_thread_handle(thread_handle);
 467   osthread->set_thread_id(thread_id);
 468 
 469   if (UseNUMA) {
 470     int lgrp_id = os::numa_get_group_id();
 471     if (lgrp_id != -1) {
 472       thread->set_lgrp_id(lgrp_id);
 473     }
 474   }
 475 
 476   // Initial thread state is INITIALIZED, not SUSPENDED
 477   osthread->set_state(INITIALIZED);
 478 
 479   return osthread;
 480 }
 481 
 482 
 483 bool os::create_attached_thread(JavaThread* thread) {
 484 #ifdef ASSERT
 485   thread->verify_not_published();
 486 #endif
 487   HANDLE thread_h;
 488   if (!DuplicateHandle(main_process, GetCurrentThread(), GetCurrentProcess(),
 489                        &thread_h, THREAD_ALL_ACCESS, false, 0)) {
 490     fatal("DuplicateHandle failed\n");
 491   }
 492   OSThread* osthread = create_os_thread(thread, thread_h,
 493                                         (int)current_thread_id());
 494   if (osthread == NULL) {
 495     return false;
 496   }
 497 
 498   // Initial thread state is RUNNABLE
 499   osthread->set_state(RUNNABLE);
 500 
 501   thread->set_osthread(osthread);
 502 
 503   log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ").",
 504     os::current_thread_id());
 505 
 506   return true;
 507 }
 508 
 509 bool os::create_main_thread(JavaThread* thread) {
 510 #ifdef ASSERT
 511   thread->verify_not_published();
 512 #endif
 513   if (_starting_thread == NULL) {
 514     _starting_thread = create_os_thread(thread, main_thread, main_thread_id);
 515     if (_starting_thread == NULL) {
 516       return false;
 517     }
 518   }
 519 
 520   // The primordial thread is runnable from the start)
 521   _starting_thread->set_state(RUNNABLE);
 522 
 523   thread->set_osthread(_starting_thread);
 524   return true;
 525 }
 526 
 527 // Helper function to trace _beginthreadex attributes,
 528 //  similar to os::Posix::describe_pthread_attr()
 529 static char* describe_beginthreadex_attributes(char* buf, size_t buflen,
 530                                                size_t stacksize, unsigned initflag) {
 531   stringStream ss(buf, buflen);
 532   if (stacksize == 0) {
 533     ss.print("stacksize: default, ");
 534   } else {
 535     ss.print("stacksize: " SIZE_FORMAT "k, ", stacksize / 1024);
 536   }
 537   ss.print("flags: ");
 538   #define PRINT_FLAG(f) if (initflag & f) ss.print( #f " ");
 539   #define ALL(X) \
 540     X(CREATE_SUSPENDED) \
 541     X(STACK_SIZE_PARAM_IS_A_RESERVATION)
 542   ALL(PRINT_FLAG)
 543   #undef ALL
 544   #undef PRINT_FLAG
 545   return buf;
 546 }
 547 
 548 // Allocate and initialize a new OSThread
 549 bool os::create_thread(Thread* thread, ThreadType thr_type,
 550                        size_t stack_size) {
 551   unsigned thread_id;
 552 
 553   // Allocate the OSThread object
 554   OSThread* osthread = new OSThread(NULL, NULL);
 555   if (osthread == NULL) {
 556     return false;
 557   }
 558 
 559   // Initialize support for Java interrupts
 560   HANDLE interrupt_event = CreateEvent(NULL, true, false, NULL);
 561   if (interrupt_event == NULL) {
 562     delete osthread;
 563     return NULL;
 564   }
 565   osthread->set_interrupt_event(interrupt_event);
 566   osthread->set_interrupted(false);
 567 
 568   thread->set_osthread(osthread);
 569 
 570   if (stack_size == 0) {
 571     switch (thr_type) {
 572     case os::java_thread:
 573       // Java threads use ThreadStackSize which default value can be changed with the flag -Xss
 574       if (JavaThread::stack_size_at_create() > 0) {
 575         stack_size = JavaThread::stack_size_at_create();
 576       }
 577       break;
 578     case os::compiler_thread:
 579       if (CompilerThreadStackSize > 0) {
 580         stack_size = (size_t)(CompilerThreadStackSize * K);
 581         break;
 582       } // else fall through:
 583         // use VMThreadStackSize if CompilerThreadStackSize is not defined
 584     case os::vm_thread:
 585     case os::pgc_thread:
 586     case os::cgc_thread:
 587     case os::watcher_thread:
 588       if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
 589       break;
 590     }
 591   }
 592 
 593   // Create the Win32 thread
 594   //
 595   // Contrary to what MSDN document says, "stack_size" in _beginthreadex()
 596   // does not specify stack size. Instead, it specifies the size of
 597   // initially committed space. The stack size is determined by
 598   // PE header in the executable. If the committed "stack_size" is larger
 599   // than default value in the PE header, the stack is rounded up to the
 600   // nearest multiple of 1MB. For example if the launcher has default
 601   // stack size of 320k, specifying any size less than 320k does not
 602   // affect the actual stack size at all, it only affects the initial
 603   // commitment. On the other hand, specifying 'stack_size' larger than
 604   // default value may cause significant increase in memory usage, because
 605   // not only the stack space will be rounded up to MB, but also the
 606   // entire space is committed upfront.
 607   //
 608   // Finally Windows XP added a new flag 'STACK_SIZE_PARAM_IS_A_RESERVATION'
 609   // for CreateThread() that can treat 'stack_size' as stack size. However we
 610   // are not supposed to call CreateThread() directly according to MSDN
 611   // document because JVM uses C runtime library. The good news is that the
 612   // flag appears to work with _beginthredex() as well.
 613 
 614   const unsigned initflag = CREATE_SUSPENDED | STACK_SIZE_PARAM_IS_A_RESERVATION;
 615   HANDLE thread_handle =
 616     (HANDLE)_beginthreadex(NULL,
 617                            (unsigned)stack_size,
 618                            (unsigned (__stdcall *)(void*)) thread_native_entry,
 619                            thread,
 620                            initflag,
 621                            &thread_id);
 622 
 623   char buf[64];
 624   if (thread_handle != NULL) {
 625     log_info(os, thread)("Thread started (tid: %u, attributes: %s)",
 626       thread_id, describe_beginthreadex_attributes(buf, sizeof(buf), stack_size, initflag));
 627   } else {
 628     log_warning(os, thread)("Failed to start thread - _beginthreadex failed (%s) for attributes: %s.",
 629       os::errno_name(errno), describe_beginthreadex_attributes(buf, sizeof(buf), stack_size, initflag));
 630   }
 631 
 632   if (thread_handle == NULL) {
 633     // Need to clean up stuff we've allocated so far
 634     CloseHandle(osthread->interrupt_event());
 635     thread->set_osthread(NULL);
 636     delete osthread;
 637     return NULL;
 638   }
 639 
 640   Atomic::inc_ptr((intptr_t*)&os::win32::_os_thread_count);
 641 
 642   // Store info on the Win32 thread into the OSThread
 643   osthread->set_thread_handle(thread_handle);
 644   osthread->set_thread_id(thread_id);
 645 
 646   // Initial thread state is INITIALIZED, not SUSPENDED
 647   osthread->set_state(INITIALIZED);
 648 
 649   // The thread is returned suspended (in state INITIALIZED), and is started higher up in the call chain
 650   return true;
 651 }
 652 
 653 
 654 // Free Win32 resources related to the OSThread
 655 void os::free_thread(OSThread* osthread) {
 656   assert(osthread != NULL, "osthread not set");
 657 
 658   // We are told to free resources of the argument thread,
 659   // but we can only really operate on the current thread.
 660   assert(Thread::current()->osthread() == osthread,
 661          "os::free_thread but not current thread");
 662 
 663   CloseHandle(osthread->thread_handle());
 664   CloseHandle(osthread->interrupt_event());
 665   delete osthread;
 666 }
 667 
 668 static jlong first_filetime;
 669 static jlong initial_performance_count;
 670 static jlong performance_frequency;
 671 
 672 
 673 jlong as_long(LARGE_INTEGER x) {
 674   jlong result = 0; // initialization to avoid warning
 675   set_high(&result, x.HighPart);
 676   set_low(&result, x.LowPart);
 677   return result;
 678 }
 679 
 680 
 681 jlong os::elapsed_counter() {
 682   LARGE_INTEGER count;
 683   QueryPerformanceCounter(&count);
 684   return as_long(count) - initial_performance_count;
 685 }
 686 
 687 
 688 jlong os::elapsed_frequency() {
 689   return performance_frequency;
 690 }
 691 
 692 
 693 julong os::available_memory() {
 694   return win32::available_memory();
 695 }
 696 
 697 julong os::win32::available_memory() {
 698   // Use GlobalMemoryStatusEx() because GlobalMemoryStatus() may return incorrect
 699   // value if total memory is larger than 4GB
 700   MEMORYSTATUSEX ms;
 701   ms.dwLength = sizeof(ms);
 702   GlobalMemoryStatusEx(&ms);
 703 
 704   return (julong)ms.ullAvailPhys;
 705 }
 706 
 707 julong os::physical_memory() {
 708   return win32::physical_memory();
 709 }
 710 
 711 bool os::has_allocatable_memory_limit(julong* limit) {
 712   MEMORYSTATUSEX ms;
 713   ms.dwLength = sizeof(ms);
 714   GlobalMemoryStatusEx(&ms);
 715 #ifdef _LP64
 716   *limit = (julong)ms.ullAvailVirtual;
 717   return true;
 718 #else
 719   // Limit to 1400m because of the 2gb address space wall
 720   *limit = MIN2((julong)1400*M, (julong)ms.ullAvailVirtual);
 721   return true;
 722 #endif
 723 }
 724 
 725 int os::active_processor_count() {
 726   DWORD_PTR lpProcessAffinityMask = 0;
 727   DWORD_PTR lpSystemAffinityMask = 0;
 728   int proc_count = processor_count();
 729   if (proc_count <= sizeof(UINT_PTR) * BitsPerByte &&
 730       GetProcessAffinityMask(GetCurrentProcess(), &lpProcessAffinityMask, &lpSystemAffinityMask)) {
 731     // Nof active processors is number of bits in process affinity mask
 732     int bitcount = 0;
 733     while (lpProcessAffinityMask != 0) {
 734       lpProcessAffinityMask = lpProcessAffinityMask & (lpProcessAffinityMask-1);
 735       bitcount++;
 736     }
 737     return bitcount;
 738   } else {
 739     return proc_count;
 740   }
 741 }
 742 
 743 void os::set_native_thread_name(const char *name) {
 744 
 745   // See: http://msdn.microsoft.com/en-us/library/xcb2z8hs.aspx
 746   //
 747   // Note that unfortunately this only works if the process
 748   // is already attached to a debugger; debugger must observe
 749   // the exception below to show the correct name.
 750 
 751   // If there is no debugger attached skip raising the exception
 752   if (!IsDebuggerPresent()) {
 753     return;
 754   }
 755 
 756   const DWORD MS_VC_EXCEPTION = 0x406D1388;
 757   struct {
 758     DWORD dwType;     // must be 0x1000
 759     LPCSTR szName;    // pointer to name (in user addr space)
 760     DWORD dwThreadID; // thread ID (-1=caller thread)
 761     DWORD dwFlags;    // reserved for future use, must be zero
 762   } info;
 763 
 764   info.dwType = 0x1000;
 765   info.szName = name;
 766   info.dwThreadID = -1;
 767   info.dwFlags = 0;
 768 
 769   __try {
 770     RaiseException (MS_VC_EXCEPTION, 0, sizeof(info)/sizeof(DWORD), (const ULONG_PTR*)&info );
 771   } __except(EXCEPTION_EXECUTE_HANDLER) {}
 772 }
 773 
 774 bool os::distribute_processes(uint length, uint* distribution) {
 775   // Not yet implemented.
 776   return false;
 777 }
 778 
 779 bool os::bind_to_processor(uint processor_id) {
 780   // Not yet implemented.
 781   return false;
 782 }
 783 
 784 void os::win32::initialize_performance_counter() {
 785   LARGE_INTEGER count;
 786   QueryPerformanceFrequency(&count);
 787   performance_frequency = as_long(count);
 788   QueryPerformanceCounter(&count);
 789   initial_performance_count = as_long(count);
 790 }
 791 
 792 
 793 double os::elapsedTime() {
 794   return (double) elapsed_counter() / (double) elapsed_frequency();
 795 }
 796 
 797 
 798 // Windows format:
 799 //   The FILETIME structure is a 64-bit value representing the number of 100-nanosecond intervals since January 1, 1601.
 800 // Java format:
 801 //   Java standards require the number of milliseconds since 1/1/1970
 802 
 803 // Constant offset - calculated using offset()
 804 static jlong  _offset   = 116444736000000000;
 805 // Fake time counter for reproducible results when debugging
 806 static jlong  fake_time = 0;
 807 
 808 #ifdef ASSERT
 809 // Just to be safe, recalculate the offset in debug mode
 810 static jlong _calculated_offset = 0;
 811 static int   _has_calculated_offset = 0;
 812 
 813 jlong offset() {
 814   if (_has_calculated_offset) return _calculated_offset;
 815   SYSTEMTIME java_origin;
 816   java_origin.wYear          = 1970;
 817   java_origin.wMonth         = 1;
 818   java_origin.wDayOfWeek     = 0; // ignored
 819   java_origin.wDay           = 1;
 820   java_origin.wHour          = 0;
 821   java_origin.wMinute        = 0;
 822   java_origin.wSecond        = 0;
 823   java_origin.wMilliseconds  = 0;
 824   FILETIME jot;
 825   if (!SystemTimeToFileTime(&java_origin, &jot)) {
 826     fatal("Error = %d\nWindows error", GetLastError());
 827   }
 828   _calculated_offset = jlong_from(jot.dwHighDateTime, jot.dwLowDateTime);
 829   _has_calculated_offset = 1;
 830   assert(_calculated_offset == _offset, "Calculated and constant time offsets must be equal");
 831   return _calculated_offset;
 832 }
 833 #else
 834 jlong offset() {
 835   return _offset;
 836 }
 837 #endif
 838 
 839 jlong windows_to_java_time(FILETIME wt) {
 840   jlong a = jlong_from(wt.dwHighDateTime, wt.dwLowDateTime);
 841   return (a - offset()) / 10000;
 842 }
 843 
 844 // Returns time ticks in (10th of micro seconds)
 845 jlong windows_to_time_ticks(FILETIME wt) {
 846   jlong a = jlong_from(wt.dwHighDateTime, wt.dwLowDateTime);
 847   return (a - offset());
 848 }
 849 
 850 FILETIME java_to_windows_time(jlong l) {
 851   jlong a = (l * 10000) + offset();
 852   FILETIME result;
 853   result.dwHighDateTime = high(a);
 854   result.dwLowDateTime  = low(a);
 855   return result;
 856 }
 857 
 858 bool os::supports_vtime() { return true; }
 859 bool os::enable_vtime() { return false; }
 860 bool os::vtime_enabled() { return false; }
 861 
 862 double os::elapsedVTime() {
 863   FILETIME created;
 864   FILETIME exited;
 865   FILETIME kernel;
 866   FILETIME user;
 867   if (GetThreadTimes(GetCurrentThread(), &created, &exited, &kernel, &user) != 0) {
 868     // the resolution of windows_to_java_time() should be sufficient (ms)
 869     return (double) (windows_to_java_time(kernel) + windows_to_java_time(user)) / MILLIUNITS;
 870   } else {
 871     return elapsedTime();
 872   }
 873 }
 874 
 875 jlong os::javaTimeMillis() {
 876   if (UseFakeTimers) {
 877     return fake_time++;
 878   } else {
 879     FILETIME wt;
 880     GetSystemTimeAsFileTime(&wt);
 881     return windows_to_java_time(wt);
 882   }
 883 }
 884 
 885 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
 886   FILETIME wt;
 887   GetSystemTimeAsFileTime(&wt);
 888   jlong ticks = windows_to_time_ticks(wt); // 10th of micros
 889   jlong secs = jlong(ticks / 10000000); // 10000 * 1000
 890   seconds = secs;
 891   nanos = jlong(ticks - (secs*10000000)) * 100;
 892 }
 893 
 894 jlong os::javaTimeNanos() {
 895     LARGE_INTEGER current_count;
 896     QueryPerformanceCounter(&current_count);
 897     double current = as_long(current_count);
 898     double freq = performance_frequency;
 899     jlong time = (jlong)((current/freq) * NANOSECS_PER_SEC);
 900     return time;
 901 }
 902 
 903 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
 904   jlong freq = performance_frequency;
 905   if (freq < NANOSECS_PER_SEC) {
 906     // the performance counter is 64 bits and we will
 907     // be multiplying it -- so no wrap in 64 bits
 908     info_ptr->max_value = ALL_64_BITS;
 909   } else if (freq > NANOSECS_PER_SEC) {
 910     // use the max value the counter can reach to
 911     // determine the max value which could be returned
 912     julong max_counter = (julong)ALL_64_BITS;
 913     info_ptr->max_value = (jlong)(max_counter / (freq / NANOSECS_PER_SEC));
 914   } else {
 915     // the performance counter is 64 bits and we will
 916     // be using it directly -- so no wrap in 64 bits
 917     info_ptr->max_value = ALL_64_BITS;
 918   }
 919 
 920   // using a counter, so no skipping
 921   info_ptr->may_skip_backward = false;
 922   info_ptr->may_skip_forward = false;
 923 
 924   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
 925 }
 926 
 927 char* os::local_time_string(char *buf, size_t buflen) {
 928   SYSTEMTIME st;
 929   GetLocalTime(&st);
 930   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
 931                st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond);
 932   return buf;
 933 }
 934 
 935 bool os::getTimesSecs(double* process_real_time,
 936                       double* process_user_time,
 937                       double* process_system_time) {
 938   HANDLE h_process = GetCurrentProcess();
 939   FILETIME create_time, exit_time, kernel_time, user_time;
 940   BOOL result = GetProcessTimes(h_process,
 941                                 &create_time,
 942                                 &exit_time,
 943                                 &kernel_time,
 944                                 &user_time);
 945   if (result != 0) {
 946     FILETIME wt;
 947     GetSystemTimeAsFileTime(&wt);
 948     jlong rtc_millis = windows_to_java_time(wt);
 949     *process_real_time = ((double) rtc_millis) / ((double) MILLIUNITS);
 950     *process_user_time =
 951       (double) jlong_from(user_time.dwHighDateTime, user_time.dwLowDateTime) / (10 * MICROUNITS);
 952     *process_system_time =
 953       (double) jlong_from(kernel_time.dwHighDateTime, kernel_time.dwLowDateTime) / (10 * MICROUNITS);
 954     return true;
 955   } else {
 956     return false;
 957   }
 958 }
 959 
 960 void os::shutdown() {
 961   // allow PerfMemory to attempt cleanup of any persistent resources
 962   perfMemory_exit();
 963 
 964   // flush buffered output, finish log files
 965   ostream_abort();
 966 
 967   // Check for abort hook
 968   abort_hook_t abort_hook = Arguments::abort_hook();
 969   if (abort_hook != NULL) {
 970     abort_hook();
 971   }
 972 }
 973 
 974 
 975 static BOOL (WINAPI *_MiniDumpWriteDump)(HANDLE, DWORD, HANDLE, MINIDUMP_TYPE,
 976                                          PMINIDUMP_EXCEPTION_INFORMATION,
 977                                          PMINIDUMP_USER_STREAM_INFORMATION,
 978                                          PMINIDUMP_CALLBACK_INFORMATION);
 979 
 980 static HANDLE dumpFile = NULL;
 981 
 982 // Check if dump file can be created.
 983 void os::check_dump_limit(char* buffer, size_t buffsz) {
 984   bool status = true;
 985   if (!FLAG_IS_DEFAULT(CreateCoredumpOnCrash) && !CreateCoredumpOnCrash) {
 986     jio_snprintf(buffer, buffsz, "CreateCoredumpOnCrash is disabled from command line");
 987     status = false;
 988   }
 989 
 990 #ifndef ASSERT
 991   if (!os::win32::is_windows_server() && FLAG_IS_DEFAULT(CreateCoredumpOnCrash)) {
 992     jio_snprintf(buffer, buffsz, "Minidumps are not enabled by default on client versions of Windows");
 993     status = false;
 994   }
 995 #endif
 996 
 997   if (status) {
 998     const char* cwd = get_current_directory(NULL, 0);
 999     int pid = current_process_id();
1000     if (cwd != NULL) {
1001       jio_snprintf(buffer, buffsz, "%s\\hs_err_pid%u.mdmp", cwd, pid);
1002     } else {
1003       jio_snprintf(buffer, buffsz, ".\\hs_err_pid%u.mdmp", pid);
1004     }
1005 
1006     if (dumpFile == NULL &&
1007        (dumpFile = CreateFile(buffer, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL))
1008                  == INVALID_HANDLE_VALUE) {
1009       jio_snprintf(buffer, buffsz, "Failed to create minidump file (0x%x).", GetLastError());
1010       status = false;
1011     }
1012   }
1013   VMError::record_coredump_status(buffer, status);
1014 }
1015 
1016 void os::abort(bool dump_core, void* siginfo, const void* context) {
1017   EXCEPTION_POINTERS ep;
1018   MINIDUMP_EXCEPTION_INFORMATION mei;
1019   MINIDUMP_EXCEPTION_INFORMATION* pmei;
1020 
1021   HANDLE hProcess = GetCurrentProcess();
1022   DWORD processId = GetCurrentProcessId();
1023   MINIDUMP_TYPE dumpType;
1024 
1025   shutdown();
1026   if (!dump_core || dumpFile == NULL) {
1027     if (dumpFile != NULL) {
1028       CloseHandle(dumpFile);
1029     }
1030     win32::exit_process_or_thread(win32::EPT_PROCESS, 1);
1031   }
1032 
1033   dumpType = (MINIDUMP_TYPE)(MiniDumpWithFullMemory | MiniDumpWithHandleData |
1034     MiniDumpWithFullMemoryInfo | MiniDumpWithThreadInfo | MiniDumpWithUnloadedModules);
1035 
1036   if (siginfo != NULL && context != NULL) {
1037     ep.ContextRecord = (PCONTEXT) context;
1038     ep.ExceptionRecord = (PEXCEPTION_RECORD) siginfo;
1039 
1040     mei.ThreadId = GetCurrentThreadId();
1041     mei.ExceptionPointers = &ep;
1042     pmei = &mei;
1043   } else {
1044     pmei = NULL;
1045   }
1046 
1047   // Older versions of dbghelp.dll (the one shipped with Win2003 for example) may not support all
1048   // the dump types we really want. If first call fails, lets fall back to just use MiniDumpWithFullMemory then.
1049   if (!WindowsDbgHelp::miniDumpWriteDump(hProcess, processId, dumpFile, dumpType, pmei, NULL, NULL) &&
1050       !WindowsDbgHelp::miniDumpWriteDump(hProcess, processId, dumpFile, (MINIDUMP_TYPE)MiniDumpWithFullMemory, pmei, NULL, NULL)) {
1051     jio_fprintf(stderr, "Call to MiniDumpWriteDump() failed (Error 0x%x)\n", GetLastError());
1052   }
1053   CloseHandle(dumpFile);
1054   win32::exit_process_or_thread(win32::EPT_PROCESS, 1);
1055 }
1056 
1057 // Die immediately, no exit hook, no abort hook, no cleanup.
1058 void os::die() {
1059   win32::exit_process_or_thread(win32::EPT_PROCESS_DIE, -1);
1060 }
1061 
1062 // Directory routines copied from src/win32/native/java/io/dirent_md.c
1063 //  * dirent_md.c       1.15 00/02/02
1064 //
1065 // The declarations for DIR and struct dirent are in jvm_win32.h.
1066 
1067 // Caller must have already run dirname through JVM_NativePath, which removes
1068 // duplicate slashes and converts all instances of '/' into '\\'.
1069 
1070 DIR * os::opendir(const char *dirname) {
1071   assert(dirname != NULL, "just checking");   // hotspot change
1072   DIR *dirp = (DIR *)malloc(sizeof(DIR), mtInternal);
1073   DWORD fattr;                                // hotspot change
1074   char alt_dirname[4] = { 0, 0, 0, 0 };
1075 
1076   if (dirp == 0) {
1077     errno = ENOMEM;
1078     return 0;
1079   }
1080 
1081   // Win32 accepts "\" in its POSIX stat(), but refuses to treat it
1082   // as a directory in FindFirstFile().  We detect this case here and
1083   // prepend the current drive name.
1084   //
1085   if (dirname[1] == '\0' && dirname[0] == '\\') {
1086     alt_dirname[0] = _getdrive() + 'A' - 1;
1087     alt_dirname[1] = ':';
1088     alt_dirname[2] = '\\';
1089     alt_dirname[3] = '\0';
1090     dirname = alt_dirname;
1091   }
1092 
1093   dirp->path = (char *)malloc(strlen(dirname) + 5, mtInternal);
1094   if (dirp->path == 0) {
1095     free(dirp);
1096     errno = ENOMEM;
1097     return 0;
1098   }
1099   strcpy(dirp->path, dirname);
1100 
1101   fattr = GetFileAttributes(dirp->path);
1102   if (fattr == 0xffffffff) {
1103     free(dirp->path);
1104     free(dirp);
1105     errno = ENOENT;
1106     return 0;
1107   } else if ((fattr & FILE_ATTRIBUTE_DIRECTORY) == 0) {
1108     free(dirp->path);
1109     free(dirp);
1110     errno = ENOTDIR;
1111     return 0;
1112   }
1113 
1114   // Append "*.*", or possibly "\\*.*", to path
1115   if (dirp->path[1] == ':' &&
1116       (dirp->path[2] == '\0' ||
1117       (dirp->path[2] == '\\' && dirp->path[3] == '\0'))) {
1118     // No '\\' needed for cases like "Z:" or "Z:\"
1119     strcat(dirp->path, "*.*");
1120   } else {
1121     strcat(dirp->path, "\\*.*");
1122   }
1123 
1124   dirp->handle = FindFirstFile(dirp->path, &dirp->find_data);
1125   if (dirp->handle == INVALID_HANDLE_VALUE) {
1126     if (GetLastError() != ERROR_FILE_NOT_FOUND) {
1127       free(dirp->path);
1128       free(dirp);
1129       errno = EACCES;
1130       return 0;
1131     }
1132   }
1133   return dirp;
1134 }
1135 
1136 // parameter dbuf unused on Windows
1137 struct dirent * os::readdir(DIR *dirp, dirent *dbuf) {
1138   assert(dirp != NULL, "just checking");      // hotspot change
1139   if (dirp->handle == INVALID_HANDLE_VALUE) {
1140     return 0;
1141   }
1142 
1143   strcpy(dirp->dirent.d_name, dirp->find_data.cFileName);
1144 
1145   if (!FindNextFile(dirp->handle, &dirp->find_data)) {
1146     if (GetLastError() == ERROR_INVALID_HANDLE) {
1147       errno = EBADF;
1148       return 0;
1149     }
1150     FindClose(dirp->handle);
1151     dirp->handle = INVALID_HANDLE_VALUE;
1152   }
1153 
1154   return &dirp->dirent;
1155 }
1156 
1157 int os::closedir(DIR *dirp) {
1158   assert(dirp != NULL, "just checking");      // hotspot change
1159   if (dirp->handle != INVALID_HANDLE_VALUE) {
1160     if (!FindClose(dirp->handle)) {
1161       errno = EBADF;
1162       return -1;
1163     }
1164     dirp->handle = INVALID_HANDLE_VALUE;
1165   }
1166   free(dirp->path);
1167   free(dirp);
1168   return 0;
1169 }
1170 
1171 // This must be hard coded because it's the system's temporary
1172 // directory not the java application's temp directory, ala java.io.tmpdir.
1173 const char* os::get_temp_directory() {
1174   static char path_buf[MAX_PATH];
1175   if (GetTempPath(MAX_PATH, path_buf) > 0) {
1176     return path_buf;
1177   } else {
1178     path_buf[0] = '\0';
1179     return path_buf;
1180   }
1181 }
1182 
1183 // Needs to be in os specific directory because windows requires another
1184 // header file <direct.h>
1185 const char* os::get_current_directory(char *buf, size_t buflen) {
1186   int n = static_cast<int>(buflen);
1187   if (buflen > INT_MAX)  n = INT_MAX;
1188   return _getcwd(buf, n);
1189 }
1190 
1191 //-----------------------------------------------------------
1192 // Helper functions for fatal error handler
1193 #ifdef _WIN64
1194 // Helper routine which returns true if address in
1195 // within the NTDLL address space.
1196 //
1197 static bool _addr_in_ntdll(address addr) {
1198   HMODULE hmod;
1199   MODULEINFO minfo;
1200 
1201   hmod = GetModuleHandle("NTDLL.DLL");
1202   if (hmod == NULL) return false;
1203   if (!GetModuleInformation(GetCurrentProcess(), hmod,
1204                                           &minfo, sizeof(MODULEINFO))) {
1205     return false;
1206   }
1207 
1208   if ((addr >= minfo.lpBaseOfDll) &&
1209       (addr < (address)((uintptr_t)minfo.lpBaseOfDll + (uintptr_t)minfo.SizeOfImage))) {
1210     return true;
1211   } else {
1212     return false;
1213   }
1214 }
1215 #endif
1216 
1217 struct _modinfo {
1218   address addr;
1219   char*   full_path;   // point to a char buffer
1220   int     buflen;      // size of the buffer
1221   address base_addr;
1222 };
1223 
1224 static int _locate_module_by_addr(const char * mod_fname, address base_addr,
1225                                   address top_address, void * param) {
1226   struct _modinfo *pmod = (struct _modinfo *)param;
1227   if (!pmod) return -1;
1228 
1229   if (base_addr   <= pmod->addr &&
1230       top_address > pmod->addr) {
1231     // if a buffer is provided, copy path name to the buffer
1232     if (pmod->full_path) {
1233       jio_snprintf(pmod->full_path, pmod->buflen, "%s", mod_fname);
1234     }
1235     pmod->base_addr = base_addr;
1236     return 1;
1237   }
1238   return 0;
1239 }
1240 
1241 bool os::dll_address_to_library_name(address addr, char* buf,
1242                                      int buflen, int* offset) {
1243   // buf is not optional, but offset is optional
1244   assert(buf != NULL, "sanity check");
1245 
1246 // NOTE: the reason we don't use SymGetModuleInfo() is it doesn't always
1247 //       return the full path to the DLL file, sometimes it returns path
1248 //       to the corresponding PDB file (debug info); sometimes it only
1249 //       returns partial path, which makes life painful.
1250 
1251   struct _modinfo mi;
1252   mi.addr      = addr;
1253   mi.full_path = buf;
1254   mi.buflen    = buflen;
1255   if (get_loaded_modules_info(_locate_module_by_addr, (void *)&mi)) {
1256     // buf already contains path name
1257     if (offset) *offset = addr - mi.base_addr;
1258     return true;
1259   }
1260 
1261   buf[0] = '\0';
1262   if (offset) *offset = -1;
1263   return false;
1264 }
1265 
1266 bool os::dll_address_to_function_name(address addr, char *buf,
1267                                       int buflen, int *offset,
1268                                       bool demangle) {
1269   // buf is not optional, but offset is optional
1270   assert(buf != NULL, "sanity check");
1271 
1272   if (Decoder::decode(addr, buf, buflen, offset, demangle)) {
1273     return true;
1274   }
1275   if (offset != NULL)  *offset  = -1;
1276   buf[0] = '\0';
1277   return false;
1278 }
1279 
1280 // save the start and end address of jvm.dll into param[0] and param[1]
1281 static int _locate_jvm_dll(const char* mod_fname, address base_addr,
1282                            address top_address, void * param) {
1283   if (!param) return -1;
1284 
1285   if (base_addr   <= (address)_locate_jvm_dll &&
1286       top_address > (address)_locate_jvm_dll) {
1287     ((address*)param)[0] = base_addr;
1288     ((address*)param)[1] = top_address;
1289     return 1;
1290   }
1291   return 0;
1292 }
1293 
1294 address vm_lib_location[2];    // start and end address of jvm.dll
1295 
1296 // check if addr is inside jvm.dll
1297 bool os::address_is_in_vm(address addr) {
1298   if (!vm_lib_location[0] || !vm_lib_location[1]) {
1299     if (!get_loaded_modules_info(_locate_jvm_dll, (void *)vm_lib_location)) {
1300       assert(false, "Can't find jvm module.");
1301       return false;
1302     }
1303   }
1304 
1305   return (vm_lib_location[0] <= addr) && (addr < vm_lib_location[1]);
1306 }
1307 
1308 // print module info; param is outputStream*
1309 static int _print_module(const char* fname, address base_address,
1310                          address top_address, void* param) {
1311   if (!param) return -1;
1312 
1313   outputStream* st = (outputStream*)param;
1314 
1315   st->print(PTR_FORMAT " - " PTR_FORMAT " \t%s\n", base_address, top_address, fname);
1316   return 0;
1317 }
1318 
1319 // Loads .dll/.so and
1320 // in case of error it checks if .dll/.so was built for the
1321 // same architecture as Hotspot is running on
1322 void * os::dll_load(const char *name, char *ebuf, int ebuflen) {
1323   void * result = LoadLibrary(name);
1324   if (result != NULL) {
1325     if (InitializeDbgHelpEarly) {
1326       // Recalculate pdb search path if a DLL was loaded successfully.
1327       SymbolEngine::recalc_search_path();
1328     }
1329     return result;
1330   }
1331 
1332   DWORD errcode = GetLastError();
1333   if (errcode == ERROR_MOD_NOT_FOUND) {
1334     strncpy(ebuf, "Can't find dependent libraries", ebuflen - 1);
1335     ebuf[ebuflen - 1] = '\0';
1336     return NULL;
1337   }
1338 
1339   // Parsing dll below
1340   // If we can read dll-info and find that dll was built
1341   // for an architecture other than Hotspot is running in
1342   // - then print to buffer "DLL was built for a different architecture"
1343   // else call os::lasterror to obtain system error message
1344 
1345   // Read system error message into ebuf
1346   // It may or may not be overwritten below (in the for loop and just above)
1347   lasterror(ebuf, (size_t) ebuflen);
1348   ebuf[ebuflen - 1] = '\0';
1349   int fd = ::open(name, O_RDONLY | O_BINARY, 0);
1350   if (fd < 0) {
1351     return NULL;
1352   }
1353 
1354   uint32_t signature_offset;
1355   uint16_t lib_arch = 0;
1356   bool failed_to_get_lib_arch =
1357     ( // Go to position 3c in the dll
1358      (os::seek_to_file_offset(fd, IMAGE_FILE_PTR_TO_SIGNATURE) < 0)
1359      ||
1360      // Read location of signature
1361      (sizeof(signature_offset) !=
1362      (os::read(fd, (void*)&signature_offset, sizeof(signature_offset))))
1363      ||
1364      // Go to COFF File Header in dll
1365      // that is located after "signature" (4 bytes long)
1366      (os::seek_to_file_offset(fd,
1367      signature_offset + IMAGE_FILE_SIGNATURE_LENGTH) < 0)
1368      ||
1369      // Read field that contains code of architecture
1370      // that dll was built for
1371      (sizeof(lib_arch) != (os::read(fd, (void*)&lib_arch, sizeof(lib_arch))))
1372     );
1373 
1374   ::close(fd);
1375   if (failed_to_get_lib_arch) {
1376     // file i/o error - report os::lasterror(...) msg
1377     return NULL;
1378   }
1379 
1380   typedef struct {
1381     uint16_t arch_code;
1382     char* arch_name;
1383   } arch_t;
1384 
1385   static const arch_t arch_array[] = {
1386     {IMAGE_FILE_MACHINE_I386,      (char*)"IA 32"},
1387     {IMAGE_FILE_MACHINE_AMD64,     (char*)"AMD 64"}
1388   };
1389 #if (defined _M_AMD64)
1390   static const uint16_t running_arch = IMAGE_FILE_MACHINE_AMD64;
1391 #elif (defined _M_IX86)
1392   static const uint16_t running_arch = IMAGE_FILE_MACHINE_I386;
1393 #else
1394   #error Method os::dll_load requires that one of following \
1395          is defined :_M_AMD64 or _M_IX86
1396 #endif
1397 
1398 
1399   // Obtain a string for printf operation
1400   // lib_arch_str shall contain string what platform this .dll was built for
1401   // running_arch_str shall string contain what platform Hotspot was built for
1402   char *running_arch_str = NULL, *lib_arch_str = NULL;
1403   for (unsigned int i = 0; i < ARRAY_SIZE(arch_array); i++) {
1404     if (lib_arch == arch_array[i].arch_code) {
1405       lib_arch_str = arch_array[i].arch_name;
1406     }
1407     if (running_arch == arch_array[i].arch_code) {
1408       running_arch_str = arch_array[i].arch_name;
1409     }
1410   }
1411 
1412   assert(running_arch_str,
1413          "Didn't find running architecture code in arch_array");
1414 
1415   // If the architecture is right
1416   // but some other error took place - report os::lasterror(...) msg
1417   if (lib_arch == running_arch) {
1418     return NULL;
1419   }
1420 
1421   if (lib_arch_str != NULL) {
1422     ::_snprintf(ebuf, ebuflen - 1,
1423                 "Can't load %s-bit .dll on a %s-bit platform",
1424                 lib_arch_str, running_arch_str);
1425   } else {
1426     // don't know what architecture this dll was build for
1427     ::_snprintf(ebuf, ebuflen - 1,
1428                 "Can't load this .dll (machine code=0x%x) on a %s-bit platform",
1429                 lib_arch, running_arch_str);
1430   }
1431 
1432   return NULL;
1433 }
1434 
1435 void os::print_dll_info(outputStream *st) {
1436   st->print_cr("Dynamic libraries:");
1437   get_loaded_modules_info(_print_module, (void *)st);
1438 }
1439 
1440 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1441   HANDLE   hProcess;
1442 
1443 # define MAX_NUM_MODULES 128
1444   HMODULE     modules[MAX_NUM_MODULES];
1445   static char filename[MAX_PATH];
1446   int         result = 0;
1447 
1448   int pid = os::current_process_id();
1449   hProcess = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ,
1450                          FALSE, pid);
1451   if (hProcess == NULL) return 0;
1452 
1453   DWORD size_needed;
1454   if (!EnumProcessModules(hProcess, modules, sizeof(modules), &size_needed)) {
1455     CloseHandle(hProcess);
1456     return 0;
1457   }
1458 
1459   // number of modules that are currently loaded
1460   int num_modules = size_needed / sizeof(HMODULE);
1461 
1462   for (int i = 0; i < MIN2(num_modules, MAX_NUM_MODULES); i++) {
1463     // Get Full pathname:
1464     if (!GetModuleFileNameEx(hProcess, modules[i], filename, sizeof(filename))) {
1465       filename[0] = '\0';
1466     }
1467 
1468     MODULEINFO modinfo;
1469     if (!GetModuleInformation(hProcess, modules[i], &modinfo, sizeof(modinfo))) {
1470       modinfo.lpBaseOfDll = NULL;
1471       modinfo.SizeOfImage = 0;
1472     }
1473 
1474     // Invoke callback function
1475     result = callback(filename, (address)modinfo.lpBaseOfDll,
1476                       (address)((u8)modinfo.lpBaseOfDll + (u8)modinfo.SizeOfImage), param);
1477     if (result) break;
1478   }
1479 
1480   CloseHandle(hProcess);
1481   return result;
1482 }
1483 
1484 bool os::get_host_name(char* buf, size_t buflen) {
1485   DWORD size = (DWORD)buflen;
1486   return (GetComputerNameEx(ComputerNameDnsHostname, buf, &size) == TRUE);
1487 }
1488 
1489 void os::get_summary_os_info(char* buf, size_t buflen) {
1490   stringStream sst(buf, buflen);
1491   os::win32::print_windows_version(&sst);
1492   // chop off newline character
1493   char* nl = strchr(buf, '\n');
1494   if (nl != NULL) *nl = '\0';
1495 }
1496 
1497 int os::log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
1498   int ret = vsnprintf(buf, len, fmt, args);
1499   // Get the correct buffer size if buf is too small
1500   if (ret < 0) {
1501     return _vscprintf(fmt, args);
1502   }
1503   return ret;
1504 }
1505 
1506 static inline time_t get_mtime(const char* filename) {
1507   struct stat st;
1508   int ret = os::stat(filename, &st);
1509   assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno));
1510   return st.st_mtime;
1511 }
1512 
1513 int os::compare_file_modified_times(const char* file1, const char* file2) {
1514   time_t t1 = get_mtime(file1);
1515   time_t t2 = get_mtime(file2);
1516   return t1 - t2;
1517 }
1518 
1519 void os::print_os_info_brief(outputStream* st) {
1520   os::print_os_info(st);
1521 }
1522 
1523 void os::print_os_info(outputStream* st) {
1524 #ifdef ASSERT
1525   char buffer[1024];
1526   st->print("HostName: ");
1527   if (get_host_name(buffer, sizeof(buffer))) {
1528     st->print("%s ", buffer);
1529   } else {
1530     st->print("N/A ");
1531   }
1532 #endif
1533   st->print("OS:");
1534   os::win32::print_windows_version(st);
1535 }
1536 
1537 void os::win32::print_windows_version(outputStream* st) {
1538   OSVERSIONINFOEX osvi;
1539   VS_FIXEDFILEINFO *file_info;
1540   TCHAR kernel32_path[MAX_PATH];
1541   UINT len, ret;
1542 
1543   // Use the GetVersionEx information to see if we're on a server or
1544   // workstation edition of Windows. Starting with Windows 8.1 we can't
1545   // trust the OS version information returned by this API.
1546   ZeroMemory(&osvi, sizeof(OSVERSIONINFOEX));
1547   osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
1548   if (!GetVersionEx((OSVERSIONINFO *)&osvi)) {
1549     st->print_cr("Call to GetVersionEx failed");
1550     return;
1551   }
1552   bool is_workstation = (osvi.wProductType == VER_NT_WORKSTATION);
1553 
1554   // Get the full path to \Windows\System32\kernel32.dll and use that for
1555   // determining what version of Windows we're running on.
1556   len = MAX_PATH - (UINT)strlen("\\kernel32.dll") - 1;
1557   ret = GetSystemDirectory(kernel32_path, len);
1558   if (ret == 0 || ret > len) {
1559     st->print_cr("Call to GetSystemDirectory failed");
1560     return;
1561   }
1562   strncat(kernel32_path, "\\kernel32.dll", MAX_PATH - ret);
1563 
1564   DWORD version_size = GetFileVersionInfoSize(kernel32_path, NULL);
1565   if (version_size == 0) {
1566     st->print_cr("Call to GetFileVersionInfoSize failed");
1567     return;
1568   }
1569 
1570   LPTSTR version_info = (LPTSTR)os::malloc(version_size, mtInternal);
1571   if (version_info == NULL) {
1572     st->print_cr("Failed to allocate version_info");
1573     return;
1574   }
1575 
1576   if (!GetFileVersionInfo(kernel32_path, NULL, version_size, version_info)) {
1577     os::free(version_info);
1578     st->print_cr("Call to GetFileVersionInfo failed");
1579     return;
1580   }
1581 
1582   if (!VerQueryValue(version_info, TEXT("\\"), (LPVOID*)&file_info, &len)) {
1583     os::free(version_info);
1584     st->print_cr("Call to VerQueryValue failed");
1585     return;
1586   }
1587 
1588   int major_version = HIWORD(file_info->dwProductVersionMS);
1589   int minor_version = LOWORD(file_info->dwProductVersionMS);
1590   int build_number = HIWORD(file_info->dwProductVersionLS);
1591   int build_minor = LOWORD(file_info->dwProductVersionLS);
1592   int os_vers = major_version * 1000 + minor_version;
1593   os::free(version_info);
1594 
1595   st->print(" Windows ");
1596   switch (os_vers) {
1597 
1598   case 6000:
1599     if (is_workstation) {
1600       st->print("Vista");
1601     } else {
1602       st->print("Server 2008");
1603     }
1604     break;
1605 
1606   case 6001:
1607     if (is_workstation) {
1608       st->print("7");
1609     } else {
1610       st->print("Server 2008 R2");
1611     }
1612     break;
1613 
1614   case 6002:
1615     if (is_workstation) {
1616       st->print("8");
1617     } else {
1618       st->print("Server 2012");
1619     }
1620     break;
1621 
1622   case 6003:
1623     if (is_workstation) {
1624       st->print("8.1");
1625     } else {
1626       st->print("Server 2012 R2");
1627     }
1628     break;
1629 
1630   case 10000:
1631     if (is_workstation) {
1632       st->print("10");
1633     } else {
1634       st->print("Server 2016");
1635     }
1636     break;
1637 
1638   default:
1639     // Unrecognized windows, print out its major and minor versions
1640     st->print("%d.%d", major_version, minor_version);
1641     break;
1642   }
1643 
1644   // Retrieve SYSTEM_INFO from GetNativeSystemInfo call so that we could
1645   // find out whether we are running on 64 bit processor or not
1646   SYSTEM_INFO si;
1647   ZeroMemory(&si, sizeof(SYSTEM_INFO));
1648   GetNativeSystemInfo(&si);
1649   if (si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_AMD64) {
1650     st->print(" , 64 bit");
1651   }
1652 
1653   st->print(" Build %d", build_number);
1654   st->print(" (%d.%d.%d.%d)", major_version, minor_version, build_number, build_minor);
1655   st->cr();
1656 }
1657 
1658 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1659   // Nothing to do for now.
1660 }
1661 
1662 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1663   HKEY key;
1664   DWORD status = RegOpenKey(HKEY_LOCAL_MACHINE,
1665                "HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0", &key);
1666   if (status == ERROR_SUCCESS) {
1667     DWORD size = (DWORD)buflen;
1668     status = RegQueryValueEx(key, "ProcessorNameString", NULL, NULL, (byte*)buf, &size);
1669     if (status != ERROR_SUCCESS) {
1670         strncpy(buf, "## __CPU__", buflen);
1671     }
1672     RegCloseKey(key);
1673   } else {
1674     // Put generic cpu info to return
1675     strncpy(buf, "## __CPU__", buflen);
1676   }
1677 }
1678 
1679 void os::print_memory_info(outputStream* st) {
1680   st->print("Memory:");
1681   st->print(" %dk page", os::vm_page_size()>>10);
1682 
1683   // Use GlobalMemoryStatusEx() because GlobalMemoryStatus() may return incorrect
1684   // value if total memory is larger than 4GB
1685   MEMORYSTATUSEX ms;
1686   ms.dwLength = sizeof(ms);
1687   GlobalMemoryStatusEx(&ms);
1688 
1689   st->print(", physical %uk", os::physical_memory() >> 10);
1690   st->print("(%uk free)", os::available_memory() >> 10);
1691 
1692   st->print(", swap %uk", ms.ullTotalPageFile >> 10);
1693   st->print("(%uk free)", ms.ullAvailPageFile >> 10);
1694   st->cr();
1695 }
1696 
1697 void os::print_siginfo(outputStream *st, const void* siginfo) {
1698   const EXCEPTION_RECORD* const er = (EXCEPTION_RECORD*)siginfo;
1699   st->print("siginfo:");
1700 
1701   char tmp[64];
1702   if (os::exception_name(er->ExceptionCode, tmp, sizeof(tmp)) == NULL) {
1703     strcpy(tmp, "EXCEPTION_??");
1704   }
1705   st->print(" %s (0x%x)", tmp, er->ExceptionCode);
1706 
1707   if ((er->ExceptionCode == EXCEPTION_ACCESS_VIOLATION ||
1708        er->ExceptionCode == EXCEPTION_IN_PAGE_ERROR) &&
1709        er->NumberParameters >= 2) {
1710     switch (er->ExceptionInformation[0]) {
1711     case 0: st->print(", reading address"); break;
1712     case 1: st->print(", writing address"); break;
1713     case 8: st->print(", data execution prevention violation at address"); break;
1714     default: st->print(", ExceptionInformation=" INTPTR_FORMAT,
1715                        er->ExceptionInformation[0]);
1716     }
1717     st->print(" " INTPTR_FORMAT, er->ExceptionInformation[1]);
1718   } else {
1719     int num = er->NumberParameters;
1720     if (num > 0) {
1721       st->print(", ExceptionInformation=");
1722       for (int i = 0; i < num; i++) {
1723         st->print(INTPTR_FORMAT " ", er->ExceptionInformation[i]);
1724       }
1725     }
1726   }
1727   st->cr();
1728 }
1729 
1730 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1731   // do nothing
1732 }
1733 
1734 static char saved_jvm_path[MAX_PATH] = {0};
1735 
1736 // Find the full path to the current module, jvm.dll
1737 void os::jvm_path(char *buf, jint buflen) {
1738   // Error checking.
1739   if (buflen < MAX_PATH) {
1740     assert(false, "must use a large-enough buffer");
1741     buf[0] = '\0';
1742     return;
1743   }
1744   // Lazy resolve the path to current module.
1745   if (saved_jvm_path[0] != 0) {
1746     strcpy(buf, saved_jvm_path);
1747     return;
1748   }
1749 
1750   buf[0] = '\0';
1751   if (Arguments::sun_java_launcher_is_altjvm()) {
1752     // Support for the java launcher's '-XXaltjvm=<path>' option. Check
1753     // for a JAVA_HOME environment variable and fix up the path so it
1754     // looks like jvm.dll is installed there (append a fake suffix
1755     // hotspot/jvm.dll).
1756     char* java_home_var = ::getenv("JAVA_HOME");
1757     if (java_home_var != NULL && java_home_var[0] != 0 &&
1758         strlen(java_home_var) < (size_t)buflen) {
1759       strncpy(buf, java_home_var, buflen);
1760 
1761       // determine if this is a legacy image or modules image
1762       // modules image doesn't have "jre" subdirectory
1763       size_t len = strlen(buf);
1764       char* jrebin_p = buf + len;
1765       jio_snprintf(jrebin_p, buflen-len, "\\jre\\bin\\");
1766       if (0 != _access(buf, 0)) {
1767         jio_snprintf(jrebin_p, buflen-len, "\\bin\\");
1768       }
1769       len = strlen(buf);
1770       jio_snprintf(buf + len, buflen-len, "hotspot\\jvm.dll");
1771     }
1772   }
1773 
1774   if (buf[0] == '\0') {
1775     GetModuleFileName(vm_lib_handle, buf, buflen);
1776   }
1777   strncpy(saved_jvm_path, buf, MAX_PATH);
1778   saved_jvm_path[MAX_PATH - 1] = '\0';
1779 }
1780 
1781 
1782 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1783 #ifndef _WIN64
1784   st->print("_");
1785 #endif
1786 }
1787 
1788 
1789 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1790 #ifndef _WIN64
1791   st->print("@%d", args_size  * sizeof(int));
1792 #endif
1793 }
1794 
1795 // This method is a copy of JDK's sysGetLastErrorString
1796 // from src/windows/hpi/src/system_md.c
1797 
1798 size_t os::lasterror(char* buf, size_t len) {
1799   DWORD errval;
1800 
1801   if ((errval = GetLastError()) != 0) {
1802     // DOS error
1803     size_t n = (size_t)FormatMessage(
1804                                      FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,
1805                                      NULL,
1806                                      errval,
1807                                      0,
1808                                      buf,
1809                                      (DWORD)len,
1810                                      NULL);
1811     if (n > 3) {
1812       // Drop final '.', CR, LF
1813       if (buf[n - 1] == '\n') n--;
1814       if (buf[n - 1] == '\r') n--;
1815       if (buf[n - 1] == '.') n--;
1816       buf[n] = '\0';
1817     }
1818     return n;
1819   }
1820 
1821   if (errno != 0) {
1822     // C runtime error that has no corresponding DOS error code
1823     const char* s = os::strerror(errno);
1824     size_t n = strlen(s);
1825     if (n >= len) n = len - 1;
1826     strncpy(buf, s, n);
1827     buf[n] = '\0';
1828     return n;
1829   }
1830 
1831   return 0;
1832 }
1833 
1834 int os::get_last_error() {
1835   DWORD error = GetLastError();
1836   if (error == 0) {
1837     error = errno;
1838   }
1839   return (int)error;
1840 }
1841 
1842 WindowsSemaphore::WindowsSemaphore(uint value) {
1843   _semaphore = ::CreateSemaphore(NULL, value, LONG_MAX, NULL);
1844 
1845   guarantee(_semaphore != NULL, "CreateSemaphore failed with error code: %lu", GetLastError());
1846 }
1847 
1848 WindowsSemaphore::~WindowsSemaphore() {
1849   ::CloseHandle(_semaphore);
1850 }
1851 
1852 void WindowsSemaphore::signal(uint count) {
1853   if (count > 0) {
1854     BOOL ret = ::ReleaseSemaphore(_semaphore, count, NULL);
1855 
1856     assert(ret != 0, "ReleaseSemaphore failed with error code: %lu", GetLastError());
1857   }
1858 }
1859 
1860 void WindowsSemaphore::wait() {
1861   DWORD ret = ::WaitForSingleObject(_semaphore, INFINITE);
1862   assert(ret != WAIT_FAILED,   "WaitForSingleObject failed with error code: %lu", GetLastError());
1863   assert(ret == WAIT_OBJECT_0, "WaitForSingleObject failed with return value: %lu", ret);
1864 }
1865 
1866 bool WindowsSemaphore::trywait() {
1867   DWORD ret = ::WaitForSingleObject(_semaphore, 0);
1868   assert(ret != WAIT_FAILED,   "WaitForSingleObject failed with error code: %lu", GetLastError());
1869   return ret == WAIT_OBJECT_0;
1870 }
1871 
1872 // sun.misc.Signal
1873 // NOTE that this is a workaround for an apparent kernel bug where if
1874 // a signal handler for SIGBREAK is installed then that signal handler
1875 // takes priority over the console control handler for CTRL_CLOSE_EVENT.
1876 // See bug 4416763.
1877 static void (*sigbreakHandler)(int) = NULL;
1878 
1879 static void UserHandler(int sig, void *siginfo, void *context) {
1880   os::signal_notify(sig);
1881   // We need to reinstate the signal handler each time...
1882   os::signal(sig, (void*)UserHandler);
1883 }
1884 
1885 void* os::user_handler() {
1886   return (void*) UserHandler;
1887 }
1888 
1889 void* os::signal(int signal_number, void* handler) {
1890   if ((signal_number == SIGBREAK) && (!ReduceSignalUsage)) {
1891     void (*oldHandler)(int) = sigbreakHandler;
1892     sigbreakHandler = (void (*)(int)) handler;
1893     return (void*) oldHandler;
1894   } else {
1895     return (void*)::signal(signal_number, (void (*)(int))handler);
1896   }
1897 }
1898 
1899 void os::signal_raise(int signal_number) {
1900   raise(signal_number);
1901 }
1902 
1903 // The Win32 C runtime library maps all console control events other than ^C
1904 // into SIGBREAK, which makes it impossible to distinguish ^BREAK from close,
1905 // logoff, and shutdown events.  We therefore install our own console handler
1906 // that raises SIGTERM for the latter cases.
1907 //
1908 static BOOL WINAPI consoleHandler(DWORD event) {
1909   switch (event) {
1910   case CTRL_C_EVENT:
1911     if (VMError::is_error_reported()) {
1912       // Ctrl-C is pressed during error reporting, likely because the error
1913       // handler fails to abort. Let VM die immediately.
1914       os::die();
1915     }
1916 
1917     os::signal_raise(SIGINT);
1918     return TRUE;
1919     break;
1920   case CTRL_BREAK_EVENT:
1921     if (sigbreakHandler != NULL) {
1922       (*sigbreakHandler)(SIGBREAK);
1923     }
1924     return TRUE;
1925     break;
1926   case CTRL_LOGOFF_EVENT: {
1927     // Don't terminate JVM if it is running in a non-interactive session,
1928     // such as a service process.
1929     USEROBJECTFLAGS flags;
1930     HANDLE handle = GetProcessWindowStation();
1931     if (handle != NULL &&
1932         GetUserObjectInformation(handle, UOI_FLAGS, &flags,
1933         sizeof(USEROBJECTFLAGS), NULL)) {
1934       // If it is a non-interactive session, let next handler to deal
1935       // with it.
1936       if ((flags.dwFlags & WSF_VISIBLE) == 0) {
1937         return FALSE;
1938       }
1939     }
1940   }
1941   case CTRL_CLOSE_EVENT:
1942   case CTRL_SHUTDOWN_EVENT:
1943     os::signal_raise(SIGTERM);
1944     return TRUE;
1945     break;
1946   default:
1947     break;
1948   }
1949   return FALSE;
1950 }
1951 
1952 // The following code is moved from os.cpp for making this
1953 // code platform specific, which it is by its very nature.
1954 
1955 // Return maximum OS signal used + 1 for internal use only
1956 // Used as exit signal for signal_thread
1957 int os::sigexitnum_pd() {
1958   return NSIG;
1959 }
1960 
1961 // a counter for each possible signal value, including signal_thread exit signal
1962 static volatile jint pending_signals[NSIG+1] = { 0 };
1963 static HANDLE sig_sem = NULL;
1964 
1965 void os::signal_init_pd() {
1966   // Initialize signal structures
1967   memset((void*)pending_signals, 0, sizeof(pending_signals));
1968 
1969   sig_sem = ::CreateSemaphore(NULL, 0, NSIG+1, NULL);
1970 
1971   // Programs embedding the VM do not want it to attempt to receive
1972   // events like CTRL_LOGOFF_EVENT, which are used to implement the
1973   // shutdown hooks mechanism introduced in 1.3.  For example, when
1974   // the VM is run as part of a Windows NT service (i.e., a servlet
1975   // engine in a web server), the correct behavior is for any console
1976   // control handler to return FALSE, not TRUE, because the OS's
1977   // "final" handler for such events allows the process to continue if
1978   // it is a service (while terminating it if it is not a service).
1979   // To make this behavior uniform and the mechanism simpler, we
1980   // completely disable the VM's usage of these console events if -Xrs
1981   // (=ReduceSignalUsage) is specified.  This means, for example, that
1982   // the CTRL-BREAK thread dump mechanism is also disabled in this
1983   // case.  See bugs 4323062, 4345157, and related bugs.
1984 
1985   if (!ReduceSignalUsage) {
1986     // Add a CTRL-C handler
1987     SetConsoleCtrlHandler(consoleHandler, TRUE);
1988   }
1989 }
1990 
1991 void os::signal_notify(int signal_number) {
1992   BOOL ret;
1993   if (sig_sem != NULL) {
1994     Atomic::inc(&pending_signals[signal_number]);
1995     ret = ::ReleaseSemaphore(sig_sem, 1, NULL);
1996     assert(ret != 0, "ReleaseSemaphore() failed");
1997   }
1998 }
1999 
2000 static int check_pending_signals(bool wait_for_signal) {
2001   DWORD ret;
2002   while (true) {
2003     for (int i = 0; i < NSIG + 1; i++) {
2004       jint n = pending_signals[i];
2005       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2006         return i;
2007       }
2008     }
2009     if (!wait_for_signal) {
2010       return -1;
2011     }
2012 
2013     JavaThread *thread = JavaThread::current();
2014 
2015     ThreadBlockInVM tbivm(thread);
2016 
2017     bool threadIsSuspended;
2018     do {
2019       thread->set_suspend_equivalent();
2020       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2021       ret = ::WaitForSingleObject(sig_sem, INFINITE);
2022       assert(ret == WAIT_OBJECT_0, "WaitForSingleObject() failed");
2023 
2024       // were we externally suspended while we were waiting?
2025       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2026       if (threadIsSuspended) {
2027         // The semaphore has been incremented, but while we were waiting
2028         // another thread suspended us. We don't want to continue running
2029         // while suspended because that would surprise the thread that
2030         // suspended us.
2031         ret = ::ReleaseSemaphore(sig_sem, 1, NULL);
2032         assert(ret != 0, "ReleaseSemaphore() failed");
2033 
2034         thread->java_suspend_self();
2035       }
2036     } while (threadIsSuspended);
2037   }
2038 }
2039 
2040 int os::signal_lookup() {
2041   return check_pending_signals(false);
2042 }
2043 
2044 int os::signal_wait() {
2045   return check_pending_signals(true);
2046 }
2047 
2048 // Implicit OS exception handling
2049 
2050 LONG Handle_Exception(struct _EXCEPTION_POINTERS* exceptionInfo,
2051                       address handler) {
2052   JavaThread* thread = (JavaThread*) Thread::current_or_null();
2053   // Save pc in thread
2054 #ifdef _M_AMD64
2055   // Do not blow up if no thread info available.
2056   if (thread) {
2057     thread->set_saved_exception_pc((address)(DWORD_PTR)exceptionInfo->ContextRecord->Rip);
2058   }
2059   // Set pc to handler
2060   exceptionInfo->ContextRecord->Rip = (DWORD64)handler;
2061 #else
2062   // Do not blow up if no thread info available.
2063   if (thread) {
2064     thread->set_saved_exception_pc((address)(DWORD_PTR)exceptionInfo->ContextRecord->Eip);
2065   }
2066   // Set pc to handler
2067   exceptionInfo->ContextRecord->Eip = (DWORD)(DWORD_PTR)handler;
2068 #endif
2069 
2070   // Continue the execution
2071   return EXCEPTION_CONTINUE_EXECUTION;
2072 }
2073 
2074 
2075 // Used for PostMortemDump
2076 extern "C" void safepoints();
2077 extern "C" void find(int x);
2078 extern "C" void events();
2079 
2080 // According to Windows API documentation, an illegal instruction sequence should generate
2081 // the 0xC000001C exception code. However, real world experience shows that occasionnaly
2082 // the execution of an illegal instruction can generate the exception code 0xC000001E. This
2083 // seems to be an undocumented feature of Win NT 4.0 (and probably other Windows systems).
2084 
2085 #define EXCEPTION_ILLEGAL_INSTRUCTION_2 0xC000001E
2086 
2087 // From "Execution Protection in the Windows Operating System" draft 0.35
2088 // Once a system header becomes available, the "real" define should be
2089 // included or copied here.
2090 #define EXCEPTION_INFO_EXEC_VIOLATION 0x08
2091 
2092 // Windows Vista/2008 heap corruption check
2093 #define EXCEPTION_HEAP_CORRUPTION        0xC0000374
2094 
2095 // All Visual C++ exceptions thrown from code generated by the Microsoft Visual
2096 // C++ compiler contain this error code. Because this is a compiler-generated
2097 // error, the code is not listed in the Win32 API header files.
2098 // The code is actually a cryptic mnemonic device, with the initial "E"
2099 // standing for "exception" and the final 3 bytes (0x6D7363) representing the
2100 // ASCII values of "msc".
2101 
2102 #define EXCEPTION_UNCAUGHT_CXX_EXCEPTION    0xE06D7363
2103 
2104 #define def_excpt(val) { #val, (val) }
2105 
2106 static const struct { char* name; uint number; } exceptlabels[] = {
2107     def_excpt(EXCEPTION_ACCESS_VIOLATION),
2108     def_excpt(EXCEPTION_DATATYPE_MISALIGNMENT),
2109     def_excpt(EXCEPTION_BREAKPOINT),
2110     def_excpt(EXCEPTION_SINGLE_STEP),
2111     def_excpt(EXCEPTION_ARRAY_BOUNDS_EXCEEDED),
2112     def_excpt(EXCEPTION_FLT_DENORMAL_OPERAND),
2113     def_excpt(EXCEPTION_FLT_DIVIDE_BY_ZERO),
2114     def_excpt(EXCEPTION_FLT_INEXACT_RESULT),
2115     def_excpt(EXCEPTION_FLT_INVALID_OPERATION),
2116     def_excpt(EXCEPTION_FLT_OVERFLOW),
2117     def_excpt(EXCEPTION_FLT_STACK_CHECK),
2118     def_excpt(EXCEPTION_FLT_UNDERFLOW),
2119     def_excpt(EXCEPTION_INT_DIVIDE_BY_ZERO),
2120     def_excpt(EXCEPTION_INT_OVERFLOW),
2121     def_excpt(EXCEPTION_PRIV_INSTRUCTION),
2122     def_excpt(EXCEPTION_IN_PAGE_ERROR),
2123     def_excpt(EXCEPTION_ILLEGAL_INSTRUCTION),
2124     def_excpt(EXCEPTION_ILLEGAL_INSTRUCTION_2),
2125     def_excpt(EXCEPTION_NONCONTINUABLE_EXCEPTION),
2126     def_excpt(EXCEPTION_STACK_OVERFLOW),
2127     def_excpt(EXCEPTION_INVALID_DISPOSITION),
2128     def_excpt(EXCEPTION_GUARD_PAGE),
2129     def_excpt(EXCEPTION_INVALID_HANDLE),
2130     def_excpt(EXCEPTION_UNCAUGHT_CXX_EXCEPTION),
2131     def_excpt(EXCEPTION_HEAP_CORRUPTION)
2132 };
2133 
2134 #undef def_excpt
2135 
2136 const char* os::exception_name(int exception_code, char *buf, size_t size) {
2137   uint code = static_cast<uint>(exception_code);
2138   for (uint i = 0; i < ARRAY_SIZE(exceptlabels); ++i) {
2139     if (exceptlabels[i].number == code) {
2140       jio_snprintf(buf, size, "%s", exceptlabels[i].name);
2141       return buf;
2142     }
2143   }
2144 
2145   return NULL;
2146 }
2147 
2148 //-----------------------------------------------------------------------------
2149 LONG Handle_IDiv_Exception(struct _EXCEPTION_POINTERS* exceptionInfo) {
2150   // handle exception caused by idiv; should only happen for -MinInt/-1
2151   // (division by zero is handled explicitly)
2152 #ifdef  _M_AMD64
2153   PCONTEXT ctx = exceptionInfo->ContextRecord;
2154   address pc = (address)ctx->Rip;
2155   assert(pc[0] >= Assembler::REX && pc[0] <= Assembler::REX_WRXB && pc[1] == 0xF7 || pc[0] == 0xF7, "not an idiv opcode");
2156   assert(pc[0] >= Assembler::REX && pc[0] <= Assembler::REX_WRXB && (pc[2] & ~0x7) == 0xF8 || (pc[1] & ~0x7) == 0xF8, "cannot handle non-register operands");
2157   if (pc[0] == 0xF7) {
2158     // set correct result values and continue after idiv instruction
2159     ctx->Rip = (DWORD64)pc + 2;        // idiv reg, reg  is 2 bytes
2160   } else {
2161     ctx->Rip = (DWORD64)pc + 3;        // REX idiv reg, reg  is 3 bytes
2162   }
2163   // Do not set ctx->Rax as it already contains the correct value (either 32 or 64 bit, depending on the operation)
2164   // this is the case because the exception only happens for -MinValue/-1 and -MinValue is always in rax because of the
2165   // idiv opcode (0xF7).
2166   ctx->Rdx = (DWORD)0;             // remainder
2167   // Continue the execution
2168 #else
2169   PCONTEXT ctx = exceptionInfo->ContextRecord;
2170   address pc = (address)ctx->Eip;
2171   assert(pc[0] == 0xF7, "not an idiv opcode");
2172   assert((pc[1] & ~0x7) == 0xF8, "cannot handle non-register operands");
2173   assert(ctx->Eax == min_jint, "unexpected idiv exception");
2174   // set correct result values and continue after idiv instruction
2175   ctx->Eip = (DWORD)pc + 2;        // idiv reg, reg  is 2 bytes
2176   ctx->Eax = (DWORD)min_jint;      // result
2177   ctx->Edx = (DWORD)0;             // remainder
2178   // Continue the execution
2179 #endif
2180   return EXCEPTION_CONTINUE_EXECUTION;
2181 }
2182 
2183 //-----------------------------------------------------------------------------
2184 LONG WINAPI Handle_FLT_Exception(struct _EXCEPTION_POINTERS* exceptionInfo) {
2185   PCONTEXT ctx = exceptionInfo->ContextRecord;
2186 #ifndef  _WIN64
2187   // handle exception caused by native method modifying control word
2188   DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode;
2189 
2190   switch (exception_code) {
2191   case EXCEPTION_FLT_DENORMAL_OPERAND:
2192   case EXCEPTION_FLT_DIVIDE_BY_ZERO:
2193   case EXCEPTION_FLT_INEXACT_RESULT:
2194   case EXCEPTION_FLT_INVALID_OPERATION:
2195   case EXCEPTION_FLT_OVERFLOW:
2196   case EXCEPTION_FLT_STACK_CHECK:
2197   case EXCEPTION_FLT_UNDERFLOW:
2198     jint fp_control_word = (* (jint*) StubRoutines::addr_fpu_cntrl_wrd_std());
2199     if (fp_control_word != ctx->FloatSave.ControlWord) {
2200       // Restore FPCW and mask out FLT exceptions
2201       ctx->FloatSave.ControlWord = fp_control_word | 0xffffffc0;
2202       // Mask out pending FLT exceptions
2203       ctx->FloatSave.StatusWord &=  0xffffff00;
2204       return EXCEPTION_CONTINUE_EXECUTION;
2205     }
2206   }
2207 
2208   if (prev_uef_handler != NULL) {
2209     // We didn't handle this exception so pass it to the previous
2210     // UnhandledExceptionFilter.
2211     return (prev_uef_handler)(exceptionInfo);
2212   }
2213 #else // !_WIN64
2214   // On Windows, the mxcsr control bits are non-volatile across calls
2215   // See also CR 6192333
2216   //
2217   jint MxCsr = INITIAL_MXCSR;
2218   // we can't use StubRoutines::addr_mxcsr_std()
2219   // because in Win64 mxcsr is not saved there
2220   if (MxCsr != ctx->MxCsr) {
2221     ctx->MxCsr = MxCsr;
2222     return EXCEPTION_CONTINUE_EXECUTION;
2223   }
2224 #endif // !_WIN64
2225 
2226   return EXCEPTION_CONTINUE_SEARCH;
2227 }
2228 
2229 static inline void report_error(Thread* t, DWORD exception_code,
2230                                 address addr, void* siginfo, void* context) {
2231   VMError::report_and_die(t, exception_code, addr, siginfo, context);
2232 
2233   // If UseOsErrorReporting, this will return here and save the error file
2234   // somewhere where we can find it in the minidump.
2235 }
2236 
2237 bool os::win32::get_frame_at_stack_banging_point(JavaThread* thread,
2238         struct _EXCEPTION_POINTERS* exceptionInfo, address pc, frame* fr) {
2239   PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2240   address addr = (address) exceptionRecord->ExceptionInformation[1];
2241   if (Interpreter::contains(pc)) {
2242     *fr = os::fetch_frame_from_context((void*)exceptionInfo->ContextRecord);
2243     if (!fr->is_first_java_frame()) {
2244       // get_frame_at_stack_banging_point() is only called when we
2245       // have well defined stacks so java_sender() calls do not need
2246       // to assert safe_for_sender() first.
2247       *fr = fr->java_sender();
2248     }
2249   } else {
2250     // more complex code with compiled code
2251     assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
2252     CodeBlob* cb = CodeCache::find_blob(pc);
2253     if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
2254       // Not sure where the pc points to, fallback to default
2255       // stack overflow handling
2256       return false;
2257     } else {
2258       *fr = os::fetch_frame_from_context((void*)exceptionInfo->ContextRecord);
2259       // in compiled code, the stack banging is performed just after the return pc
2260       // has been pushed on the stack
2261       *fr = frame(fr->sp() + 1, fr->fp(), (address)*(fr->sp()));
2262       if (!fr->is_java_frame()) {
2263         // See java_sender() comment above.
2264         *fr = fr->java_sender();
2265       }
2266     }
2267   }
2268   assert(fr->is_java_frame(), "Safety check");
2269   return true;
2270 }
2271 
2272 //-----------------------------------------------------------------------------
2273 LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
2274   if (InterceptOSException) return EXCEPTION_CONTINUE_SEARCH;
2275   DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode;
2276 #ifdef _M_AMD64
2277   address pc = (address) exceptionInfo->ContextRecord->Rip;
2278 #else
2279   address pc = (address) exceptionInfo->ContextRecord->Eip;
2280 #endif
2281   Thread* t = Thread::current_or_null_safe();
2282 
2283   // Handle SafeFetch32 and SafeFetchN exceptions.
2284   if (StubRoutines::is_safefetch_fault(pc)) {
2285     return Handle_Exception(exceptionInfo, StubRoutines::continuation_for_safefetch_fault(pc));
2286   }
2287 
2288 #ifndef _WIN64
2289   // Execution protection violation - win32 running on AMD64 only
2290   // Handled first to avoid misdiagnosis as a "normal" access violation;
2291   // This is safe to do because we have a new/unique ExceptionInformation
2292   // code for this condition.
2293   if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2294     PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2295     int exception_subcode = (int) exceptionRecord->ExceptionInformation[0];
2296     address addr = (address) exceptionRecord->ExceptionInformation[1];
2297 
2298     if (exception_subcode == EXCEPTION_INFO_EXEC_VIOLATION) {
2299       int page_size = os::vm_page_size();
2300 
2301       // Make sure the pc and the faulting address are sane.
2302       //
2303       // If an instruction spans a page boundary, and the page containing
2304       // the beginning of the instruction is executable but the following
2305       // page is not, the pc and the faulting address might be slightly
2306       // different - we still want to unguard the 2nd page in this case.
2307       //
2308       // 15 bytes seems to be a (very) safe value for max instruction size.
2309       bool pc_is_near_addr =
2310         (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
2311       bool instr_spans_page_boundary =
2312         (align_down((intptr_t) pc ^ (intptr_t) addr,
2313                          (intptr_t) page_size) > 0);
2314 
2315       if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
2316         static volatile address last_addr =
2317           (address) os::non_memory_address_word();
2318 
2319         // In conservative mode, don't unguard unless the address is in the VM
2320         if (UnguardOnExecutionViolation > 0 && addr != last_addr &&
2321             (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
2322 
2323           // Set memory to RWX and retry
2324           address page_start = align_down(addr, page_size);
2325           bool res = os::protect_memory((char*) page_start, page_size,
2326                                         os::MEM_PROT_RWX);
2327 
2328           log_debug(os)("Execution protection violation "
2329                         "at " INTPTR_FORMAT
2330                         ", unguarding " INTPTR_FORMAT ": %s", p2i(addr),
2331                         p2i(page_start), (res ? "success" : os::strerror(errno)));
2332 
2333           // Set last_addr so if we fault again at the same address, we don't
2334           // end up in an endless loop.
2335           //
2336           // There are two potential complications here.  Two threads trapping
2337           // at the same address at the same time could cause one of the
2338           // threads to think it already unguarded, and abort the VM.  Likely
2339           // very rare.
2340           //
2341           // The other race involves two threads alternately trapping at
2342           // different addresses and failing to unguard the page, resulting in
2343           // an endless loop.  This condition is probably even more unlikely
2344           // than the first.
2345           //
2346           // Although both cases could be avoided by using locks or thread
2347           // local last_addr, these solutions are unnecessary complication:
2348           // this handler is a best-effort safety net, not a complete solution.
2349           // It is disabled by default and should only be used as a workaround
2350           // in case we missed any no-execute-unsafe VM code.
2351 
2352           last_addr = addr;
2353 
2354           return EXCEPTION_CONTINUE_EXECUTION;
2355         }
2356       }
2357 
2358       // Last unguard failed or not unguarding
2359       tty->print_raw_cr("Execution protection violation");
2360       report_error(t, exception_code, addr, exceptionInfo->ExceptionRecord,
2361                    exceptionInfo->ContextRecord);
2362       return EXCEPTION_CONTINUE_SEARCH;
2363     }
2364   }
2365 #endif // _WIN64
2366 
2367   // Check to see if we caught the safepoint code in the
2368   // process of write protecting the memory serialization page.
2369   // It write enables the page immediately after protecting it
2370   // so just return.
2371   if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2372     if (t != NULL && t->is_Java_thread()) {
2373       JavaThread* thread = (JavaThread*) t;
2374       PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2375       address addr = (address) exceptionRecord->ExceptionInformation[1];
2376       if (os::is_memory_serialize_page(thread, addr)) {
2377         // Block current thread until the memory serialize page permission restored.
2378         os::block_on_serialize_page_trap();
2379         return EXCEPTION_CONTINUE_EXECUTION;
2380       }
2381     }
2382   }
2383 
2384   if ((exception_code == EXCEPTION_ACCESS_VIOLATION) &&
2385       VM_Version::is_cpuinfo_segv_addr(pc)) {
2386     // Verify that OS save/restore AVX registers.
2387     return Handle_Exception(exceptionInfo, VM_Version::cpuinfo_cont_addr());
2388   }
2389 
2390   if (t != NULL && t->is_Java_thread()) {
2391     JavaThread* thread = (JavaThread*) t;
2392     bool in_java = thread->thread_state() == _thread_in_Java;
2393 
2394     // Handle potential stack overflows up front.
2395     if (exception_code == EXCEPTION_STACK_OVERFLOW) {
2396       if (thread->stack_guards_enabled()) {
2397         if (in_java) {
2398           frame fr;
2399           PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2400           address addr = (address) exceptionRecord->ExceptionInformation[1];
2401           if (os::win32::get_frame_at_stack_banging_point(thread, exceptionInfo, pc, &fr)) {
2402             assert(fr.is_java_frame(), "Must be a Java frame");
2403             SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
2404           }
2405         }
2406         // Yellow zone violation.  The o/s has unprotected the first yellow
2407         // zone page for us.  Note:  must call disable_stack_yellow_zone to
2408         // update the enabled status, even if the zone contains only one page.
2409         assert(thread->thread_state() != _thread_in_vm, "Undersized StackShadowPages");
2410         thread->disable_stack_yellow_reserved_zone();
2411         // If not in java code, return and hope for the best.
2412         return in_java
2413             ? Handle_Exception(exceptionInfo, SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW))
2414             :  EXCEPTION_CONTINUE_EXECUTION;
2415       } else {
2416         // Fatal red zone violation.
2417         thread->disable_stack_red_zone();
2418         tty->print_raw_cr("An unrecoverable stack overflow has occurred.");
2419         report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
2420                       exceptionInfo->ContextRecord);
2421         return EXCEPTION_CONTINUE_SEARCH;
2422       }
2423     } else if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2424       // Either stack overflow or null pointer exception.
2425       if (in_java) {
2426         PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2427         address addr = (address) exceptionRecord->ExceptionInformation[1];
2428         address stack_end = thread->stack_end();
2429         if (addr < stack_end && addr >= stack_end - os::vm_page_size()) {
2430           // Stack overflow.
2431           assert(!os::uses_stack_guard_pages(),
2432                  "should be caught by red zone code above.");
2433           return Handle_Exception(exceptionInfo,
2434                                   SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW));
2435         }
2436         // Check for safepoint polling and implicit null
2437         // We only expect null pointers in the stubs (vtable)
2438         // the rest are checked explicitly now.
2439         CodeBlob* cb = CodeCache::find_blob(pc);
2440         if (cb != NULL) {
2441           if (os::is_poll_address(addr)) {
2442             address stub = SharedRuntime::get_poll_stub(pc);
2443             return Handle_Exception(exceptionInfo, stub);
2444           }
2445         }
2446         {
2447 #ifdef _WIN64
2448           // If it's a legal stack address map the entire region in
2449           //
2450           PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2451           address addr = (address) exceptionRecord->ExceptionInformation[1];
2452           if (addr > thread->stack_reserved_zone_base() && addr < thread->stack_base()) {
2453             addr = (address)((uintptr_t)addr &
2454                              (~((uintptr_t)os::vm_page_size() - (uintptr_t)1)));
2455             os::commit_memory((char *)addr, thread->stack_base() - addr,
2456                               !ExecMem);
2457             return EXCEPTION_CONTINUE_EXECUTION;
2458           } else
2459 #endif
2460           {
2461             // Null pointer exception.
2462             if (!MacroAssembler::needs_explicit_null_check((intptr_t)addr)) {
2463               address stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
2464               if (stub != NULL) return Handle_Exception(exceptionInfo, stub);
2465             }
2466             report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
2467                          exceptionInfo->ContextRecord);
2468             return EXCEPTION_CONTINUE_SEARCH;
2469           }
2470         }
2471       }
2472 
2473 #ifdef _WIN64
2474       // Special care for fast JNI field accessors.
2475       // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks
2476       // in and the heap gets shrunk before the field access.
2477       if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2478         address addr = JNI_FastGetField::find_slowcase_pc(pc);
2479         if (addr != (address)-1) {
2480           return Handle_Exception(exceptionInfo, addr);
2481         }
2482       }
2483 #endif
2484 
2485       // Stack overflow or null pointer exception in native code.
2486       report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
2487                    exceptionInfo->ContextRecord);
2488       return EXCEPTION_CONTINUE_SEARCH;
2489     } // /EXCEPTION_ACCESS_VIOLATION
2490     // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
2491 
2492     if (in_java) {
2493       switch (exception_code) {
2494       case EXCEPTION_INT_DIVIDE_BY_ZERO:
2495         return Handle_Exception(exceptionInfo, SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO));
2496 
2497       case EXCEPTION_INT_OVERFLOW:
2498         return Handle_IDiv_Exception(exceptionInfo);
2499 
2500       } // switch
2501     }
2502     if (((thread->thread_state() == _thread_in_Java) ||
2503          (thread->thread_state() == _thread_in_native)) &&
2504          exception_code != EXCEPTION_UNCAUGHT_CXX_EXCEPTION) {
2505       LONG result=Handle_FLT_Exception(exceptionInfo);
2506       if (result==EXCEPTION_CONTINUE_EXECUTION) return result;
2507     }
2508   }
2509 
2510   if (exception_code != EXCEPTION_BREAKPOINT) {
2511     report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
2512                  exceptionInfo->ContextRecord);
2513   }
2514   return EXCEPTION_CONTINUE_SEARCH;
2515 }
2516 
2517 #ifndef _WIN64
2518 // Special care for fast JNI accessors.
2519 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in and
2520 // the heap gets shrunk before the field access.
2521 // Need to install our own structured exception handler since native code may
2522 // install its own.
2523 LONG WINAPI fastJNIAccessorExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
2524   DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode;
2525   if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2526     address pc = (address) exceptionInfo->ContextRecord->Eip;
2527     address addr = JNI_FastGetField::find_slowcase_pc(pc);
2528     if (addr != (address)-1) {
2529       return Handle_Exception(exceptionInfo, addr);
2530     }
2531   }
2532   return EXCEPTION_CONTINUE_SEARCH;
2533 }
2534 
2535 #define DEFINE_FAST_GETFIELD(Return, Fieldname, Result)                     \
2536   Return JNICALL jni_fast_Get##Result##Field_wrapper(JNIEnv *env,           \
2537                                                      jobject obj,           \
2538                                                      jfieldID fieldID) {    \
2539     __try {                                                                 \
2540       return (*JNI_FastGetField::jni_fast_Get##Result##Field_fp)(env,       \
2541                                                                  obj,       \
2542                                                                  fieldID);  \
2543     } __except(fastJNIAccessorExceptionFilter((_EXCEPTION_POINTERS*)        \
2544                                               _exception_info())) {         \
2545     }                                                                       \
2546     return 0;                                                               \
2547   }
2548 
2549 DEFINE_FAST_GETFIELD(jboolean, bool,   Boolean)
2550 DEFINE_FAST_GETFIELD(jbyte,    byte,   Byte)
2551 DEFINE_FAST_GETFIELD(jchar,    char,   Char)
2552 DEFINE_FAST_GETFIELD(jshort,   short,  Short)
2553 DEFINE_FAST_GETFIELD(jint,     int,    Int)
2554 DEFINE_FAST_GETFIELD(jlong,    long,   Long)
2555 DEFINE_FAST_GETFIELD(jfloat,   float,  Float)
2556 DEFINE_FAST_GETFIELD(jdouble,  double, Double)
2557 
2558 address os::win32::fast_jni_accessor_wrapper(BasicType type) {
2559   switch (type) {
2560   case T_BOOLEAN: return (address)jni_fast_GetBooleanField_wrapper;
2561   case T_BYTE:    return (address)jni_fast_GetByteField_wrapper;
2562   case T_CHAR:    return (address)jni_fast_GetCharField_wrapper;
2563   case T_SHORT:   return (address)jni_fast_GetShortField_wrapper;
2564   case T_INT:     return (address)jni_fast_GetIntField_wrapper;
2565   case T_LONG:    return (address)jni_fast_GetLongField_wrapper;
2566   case T_FLOAT:   return (address)jni_fast_GetFloatField_wrapper;
2567   case T_DOUBLE:  return (address)jni_fast_GetDoubleField_wrapper;
2568   default:        ShouldNotReachHere();
2569   }
2570   return (address)-1;
2571 }
2572 #endif
2573 
2574 // Virtual Memory
2575 
2576 int os::vm_page_size() { return os::win32::vm_page_size(); }
2577 int os::vm_allocation_granularity() {
2578   return os::win32::vm_allocation_granularity();
2579 }
2580 
2581 // Windows large page support is available on Windows 2003. In order to use
2582 // large page memory, the administrator must first assign additional privilege
2583 // to the user:
2584 //   + select Control Panel -> Administrative Tools -> Local Security Policy
2585 //   + select Local Policies -> User Rights Assignment
2586 //   + double click "Lock pages in memory", add users and/or groups
2587 //   + reboot
2588 // Note the above steps are needed for administrator as well, as administrators
2589 // by default do not have the privilege to lock pages in memory.
2590 //
2591 // Note about Windows 2003: although the API supports committing large page
2592 // memory on a page-by-page basis and VirtualAlloc() returns success under this
2593 // scenario, I found through experiment it only uses large page if the entire
2594 // memory region is reserved and committed in a single VirtualAlloc() call.
2595 // This makes Windows large page support more or less like Solaris ISM, in
2596 // that the entire heap must be committed upfront. This probably will change
2597 // in the future, if so the code below needs to be revisited.
2598 
2599 #ifndef MEM_LARGE_PAGES
2600   #define MEM_LARGE_PAGES 0x20000000
2601 #endif
2602 
2603 static HANDLE    _hProcess;
2604 static HANDLE    _hToken;
2605 
2606 // Container for NUMA node list info
2607 class NUMANodeListHolder {
2608  private:
2609   int *_numa_used_node_list;  // allocated below
2610   int _numa_used_node_count;
2611 
2612   void free_node_list() {
2613     if (_numa_used_node_list != NULL) {
2614       FREE_C_HEAP_ARRAY(int, _numa_used_node_list);
2615     }
2616   }
2617 
2618  public:
2619   NUMANodeListHolder() {
2620     _numa_used_node_count = 0;
2621     _numa_used_node_list = NULL;
2622     // do rest of initialization in build routine (after function pointers are set up)
2623   }
2624 
2625   ~NUMANodeListHolder() {
2626     free_node_list();
2627   }
2628 
2629   bool build() {
2630     DWORD_PTR proc_aff_mask;
2631     DWORD_PTR sys_aff_mask;
2632     if (!GetProcessAffinityMask(GetCurrentProcess(), &proc_aff_mask, &sys_aff_mask)) return false;
2633     ULONG highest_node_number;
2634     if (!GetNumaHighestNodeNumber(&highest_node_number)) return false;
2635     free_node_list();
2636     _numa_used_node_list = NEW_C_HEAP_ARRAY(int, highest_node_number + 1, mtInternal);
2637     for (unsigned int i = 0; i <= highest_node_number; i++) {
2638       ULONGLONG proc_mask_numa_node;
2639       if (!GetNumaNodeProcessorMask(i, &proc_mask_numa_node)) return false;
2640       if ((proc_aff_mask & proc_mask_numa_node)!=0) {
2641         _numa_used_node_list[_numa_used_node_count++] = i;
2642       }
2643     }
2644     return (_numa_used_node_count > 1);
2645   }
2646 
2647   int get_count() { return _numa_used_node_count; }
2648   int get_node_list_entry(int n) {
2649     // for indexes out of range, returns -1
2650     return (n < _numa_used_node_count ? _numa_used_node_list[n] : -1);
2651   }
2652 
2653 } numa_node_list_holder;
2654 
2655 
2656 
2657 static size_t _large_page_size = 0;
2658 
2659 static bool request_lock_memory_privilege() {
2660   _hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE,
2661                           os::current_process_id());
2662 
2663   LUID luid;
2664   if (_hProcess != NULL &&
2665       OpenProcessToken(_hProcess, TOKEN_ADJUST_PRIVILEGES, &_hToken) &&
2666       LookupPrivilegeValue(NULL, "SeLockMemoryPrivilege", &luid)) {
2667 
2668     TOKEN_PRIVILEGES tp;
2669     tp.PrivilegeCount = 1;
2670     tp.Privileges[0].Luid = luid;
2671     tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
2672 
2673     // AdjustTokenPrivileges() may return TRUE even when it couldn't change the
2674     // privilege. Check GetLastError() too. See MSDN document.
2675     if (AdjustTokenPrivileges(_hToken, false, &tp, sizeof(tp), NULL, NULL) &&
2676         (GetLastError() == ERROR_SUCCESS)) {
2677       return true;
2678     }
2679   }
2680 
2681   return false;
2682 }
2683 
2684 static void cleanup_after_large_page_init() {
2685   if (_hProcess) CloseHandle(_hProcess);
2686   _hProcess = NULL;
2687   if (_hToken) CloseHandle(_hToken);
2688   _hToken = NULL;
2689 }
2690 
2691 static bool numa_interleaving_init() {
2692   bool success = false;
2693   bool use_numa_interleaving_specified = !FLAG_IS_DEFAULT(UseNUMAInterleaving);
2694 
2695   // print a warning if UseNUMAInterleaving flag is specified on command line
2696   bool warn_on_failure = use_numa_interleaving_specified;
2697 #define WARN(msg) if (warn_on_failure) { warning(msg); }
2698 
2699   // NUMAInterleaveGranularity cannot be less than vm_allocation_granularity (or _large_page_size if using large pages)
2700   size_t min_interleave_granularity = UseLargePages ? _large_page_size : os::vm_allocation_granularity();
2701   NUMAInterleaveGranularity = align_up(NUMAInterleaveGranularity, min_interleave_granularity);
2702 
2703   if (numa_node_list_holder.build()) {
2704     if (log_is_enabled(Debug, os, cpu)) {
2705       Log(os, cpu) log;
2706       log.debug("NUMA UsedNodeCount=%d, namely ", numa_node_list_holder.get_count());
2707       for (int i = 0; i < numa_node_list_holder.get_count(); i++) {
2708         log.debug("  %d ", numa_node_list_holder.get_node_list_entry(i));
2709       }
2710     }
2711     success = true;
2712   } else {
2713     WARN("Process does not cover multiple NUMA nodes.");
2714   }
2715   if (!success) {
2716     if (use_numa_interleaving_specified) WARN("...Ignoring UseNUMAInterleaving flag.");
2717   }
2718   return success;
2719 #undef WARN
2720 }
2721 
2722 // this routine is used whenever we need to reserve a contiguous VA range
2723 // but we need to make separate VirtualAlloc calls for each piece of the range
2724 // Reasons for doing this:
2725 //  * UseLargePagesIndividualAllocation was set (normally only needed on WS2003 but possible to be set otherwise)
2726 //  * UseNUMAInterleaving requires a separate node for each piece
2727 static char* allocate_pages_individually(size_t bytes, char* addr, DWORD flags,
2728                                          DWORD prot,
2729                                          bool should_inject_error = false) {
2730   char * p_buf;
2731   // note: at setup time we guaranteed that NUMAInterleaveGranularity was aligned up to a page size
2732   size_t page_size = UseLargePages ? _large_page_size : os::vm_allocation_granularity();
2733   size_t chunk_size = UseNUMAInterleaving ? NUMAInterleaveGranularity : page_size;
2734 
2735   // first reserve enough address space in advance since we want to be
2736   // able to break a single contiguous virtual address range into multiple
2737   // large page commits but WS2003 does not allow reserving large page space
2738   // so we just use 4K pages for reserve, this gives us a legal contiguous
2739   // address space. then we will deallocate that reservation, and re alloc
2740   // using large pages
2741   const size_t size_of_reserve = bytes + chunk_size;
2742   if (bytes > size_of_reserve) {
2743     // Overflowed.
2744     return NULL;
2745   }
2746   p_buf = (char *) VirtualAlloc(addr,
2747                                 size_of_reserve,  // size of Reserve
2748                                 MEM_RESERVE,
2749                                 PAGE_READWRITE);
2750   // If reservation failed, return NULL
2751   if (p_buf == NULL) return NULL;
2752   MemTracker::record_virtual_memory_reserve((address)p_buf, size_of_reserve, CALLER_PC);
2753   os::release_memory(p_buf, bytes + chunk_size);
2754 
2755   // we still need to round up to a page boundary (in case we are using large pages)
2756   // but not to a chunk boundary (in case InterleavingGranularity doesn't align with page size)
2757   // instead we handle this in the bytes_to_rq computation below
2758   p_buf = align_up(p_buf, page_size);
2759 
2760   // now go through and allocate one chunk at a time until all bytes are
2761   // allocated
2762   size_t  bytes_remaining = bytes;
2763   // An overflow of align_up() would have been caught above
2764   // in the calculation of size_of_reserve.
2765   char * next_alloc_addr = p_buf;
2766   HANDLE hProc = GetCurrentProcess();
2767 
2768 #ifdef ASSERT
2769   // Variable for the failure injection
2770   int ran_num = os::random();
2771   size_t fail_after = ran_num % bytes;
2772 #endif
2773 
2774   int count=0;
2775   while (bytes_remaining) {
2776     // select bytes_to_rq to get to the next chunk_size boundary
2777 
2778     size_t bytes_to_rq = MIN2(bytes_remaining, chunk_size - ((size_t)next_alloc_addr % chunk_size));
2779     // Note allocate and commit
2780     char * p_new;
2781 
2782 #ifdef ASSERT
2783     bool inject_error_now = should_inject_error && (bytes_remaining <= fail_after);
2784 #else
2785     const bool inject_error_now = false;
2786 #endif
2787 
2788     if (inject_error_now) {
2789       p_new = NULL;
2790     } else {
2791       if (!UseNUMAInterleaving) {
2792         p_new = (char *) VirtualAlloc(next_alloc_addr,
2793                                       bytes_to_rq,
2794                                       flags,
2795                                       prot);
2796       } else {
2797         // get the next node to use from the used_node_list
2798         assert(numa_node_list_holder.get_count() > 0, "Multiple NUMA nodes expected");
2799         DWORD node = numa_node_list_holder.get_node_list_entry(count % numa_node_list_holder.get_count());
2800         p_new = (char *)VirtualAllocExNuma(hProc, next_alloc_addr, bytes_to_rq, flags, prot, node);
2801       }
2802     }
2803 
2804     if (p_new == NULL) {
2805       // Free any allocated pages
2806       if (next_alloc_addr > p_buf) {
2807         // Some memory was committed so release it.
2808         size_t bytes_to_release = bytes - bytes_remaining;
2809         // NMT has yet to record any individual blocks, so it
2810         // need to create a dummy 'reserve' record to match
2811         // the release.
2812         MemTracker::record_virtual_memory_reserve((address)p_buf,
2813                                                   bytes_to_release, CALLER_PC);
2814         os::release_memory(p_buf, bytes_to_release);
2815       }
2816 #ifdef ASSERT
2817       if (should_inject_error) {
2818         log_develop_debug(pagesize)("Reserving pages individually failed.");
2819       }
2820 #endif
2821       return NULL;
2822     }
2823 
2824     bytes_remaining -= bytes_to_rq;
2825     next_alloc_addr += bytes_to_rq;
2826     count++;
2827   }
2828   // Although the memory is allocated individually, it is returned as one.
2829   // NMT records it as one block.
2830   if ((flags & MEM_COMMIT) != 0) {
2831     MemTracker::record_virtual_memory_reserve_and_commit((address)p_buf, bytes, CALLER_PC);
2832   } else {
2833     MemTracker::record_virtual_memory_reserve((address)p_buf, bytes, CALLER_PC);
2834   }
2835 
2836   // made it this far, success
2837   return p_buf;
2838 }
2839 
2840 
2841 
2842 void os::large_page_init() {
2843   if (!UseLargePages) return;
2844 
2845   // print a warning if any large page related flag is specified on command line
2846   bool warn_on_failure = !FLAG_IS_DEFAULT(UseLargePages) ||
2847                          !FLAG_IS_DEFAULT(LargePageSizeInBytes);
2848   bool success = false;
2849 
2850 #define WARN(msg) if (warn_on_failure) { warning(msg); }
2851   if (request_lock_memory_privilege()) {
2852     size_t s = GetLargePageMinimum();
2853     if (s) {
2854 #if defined(IA32) || defined(AMD64)
2855       if (s > 4*M || LargePageSizeInBytes > 4*M) {
2856         WARN("JVM cannot use large pages bigger than 4mb.");
2857       } else {
2858 #endif
2859         if (LargePageSizeInBytes && LargePageSizeInBytes % s == 0) {
2860           _large_page_size = LargePageSizeInBytes;
2861         } else {
2862           _large_page_size = s;
2863         }
2864         success = true;
2865 #if defined(IA32) || defined(AMD64)
2866       }
2867 #endif
2868     } else {
2869       WARN("Large page is not supported by the processor.");
2870     }
2871   } else {
2872     WARN("JVM cannot use large page memory because it does not have enough privilege to lock pages in memory.");
2873   }
2874 #undef WARN
2875 
2876   const size_t default_page_size = (size_t) vm_page_size();
2877   if (success && _large_page_size > default_page_size) {
2878     _page_sizes[0] = _large_page_size;
2879     _page_sizes[1] = default_page_size;
2880     _page_sizes[2] = 0;
2881   }
2882 
2883   cleanup_after_large_page_init();
2884   UseLargePages = success;
2885 }
2886 
2887 // On win32, one cannot release just a part of reserved memory, it's an
2888 // all or nothing deal.  When we split a reservation, we must break the
2889 // reservation into two reservations.
2890 void os::pd_split_reserved_memory(char *base, size_t size, size_t split,
2891                                   bool realloc) {
2892   if (size > 0) {
2893     release_memory(base, size);
2894     if (realloc) {
2895       reserve_memory(split, base);
2896     }
2897     if (size != split) {
2898       reserve_memory(size - split, base + split);
2899     }
2900   }
2901 }
2902 
2903 // Multiple threads can race in this code but it's not possible to unmap small sections of
2904 // virtual space to get requested alignment, like posix-like os's.
2905 // Windows prevents multiple thread from remapping over each other so this loop is thread-safe.
2906 char* os::reserve_memory_aligned(size_t size, size_t alignment) {
2907   assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
2908          "Alignment must be a multiple of allocation granularity (page size)");
2909   assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
2910 
2911   size_t extra_size = size + alignment;
2912   assert(extra_size >= size, "overflow, size is too large to allow alignment");
2913 
2914   char* aligned_base = NULL;
2915 
2916   do {
2917     char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
2918     if (extra_base == NULL) {
2919       return NULL;
2920     }
2921     // Do manual alignment
2922     aligned_base = align_up(extra_base, alignment);
2923 
2924     os::release_memory(extra_base, extra_size);
2925 
2926     aligned_base = os::reserve_memory(size, aligned_base);
2927 
2928   } while (aligned_base == NULL);
2929 
2930   return aligned_base;
2931 }
2932 
2933 char* os::pd_reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
2934   assert((size_t)addr % os::vm_allocation_granularity() == 0,
2935          "reserve alignment");
2936   assert(bytes % os::vm_page_size() == 0, "reserve page size");
2937   char* res;
2938   // note that if UseLargePages is on, all the areas that require interleaving
2939   // will go thru reserve_memory_special rather than thru here.
2940   bool use_individual = (UseNUMAInterleaving && !UseLargePages);
2941   if (!use_individual) {
2942     res = (char*)VirtualAlloc(addr, bytes, MEM_RESERVE, PAGE_READWRITE);
2943   } else {
2944     elapsedTimer reserveTimer;
2945     if (Verbose && PrintMiscellaneous) reserveTimer.start();
2946     // in numa interleaving, we have to allocate pages individually
2947     // (well really chunks of NUMAInterleaveGranularity size)
2948     res = allocate_pages_individually(bytes, addr, MEM_RESERVE, PAGE_READWRITE);
2949     if (res == NULL) {
2950       warning("NUMA page allocation failed");
2951     }
2952     if (Verbose && PrintMiscellaneous) {
2953       reserveTimer.stop();
2954       tty->print_cr("reserve_memory of %Ix bytes took " JLONG_FORMAT " ms (" JLONG_FORMAT " ticks)", bytes,
2955                     reserveTimer.milliseconds(), reserveTimer.ticks());
2956     }
2957   }
2958   assert(res == NULL || addr == NULL || addr == res,
2959          "Unexpected address from reserve.");
2960 
2961   return res;
2962 }
2963 
2964 // Reserve memory at an arbitrary address, only if that area is
2965 // available (and not reserved for something else).
2966 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2967   // Windows os::reserve_memory() fails of the requested address range is
2968   // not avilable.
2969   return reserve_memory(bytes, requested_addr);
2970 }
2971 
2972 size_t os::large_page_size() {
2973   return _large_page_size;
2974 }
2975 
2976 bool os::can_commit_large_page_memory() {
2977   // Windows only uses large page memory when the entire region is reserved
2978   // and committed in a single VirtualAlloc() call. This may change in the
2979   // future, but with Windows 2003 it's not possible to commit on demand.
2980   return false;
2981 }
2982 
2983 bool os::can_execute_large_page_memory() {
2984   return true;
2985 }
2986 
2987 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* addr,
2988                                  bool exec) {
2989   assert(UseLargePages, "only for large pages");
2990 
2991   if (!is_aligned(bytes, os::large_page_size()) || alignment > os::large_page_size()) {
2992     return NULL; // Fallback to small pages.
2993   }
2994 
2995   const DWORD prot = exec ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
2996   const DWORD flags = MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES;
2997 
2998   // with large pages, there are two cases where we need to use Individual Allocation
2999   // 1) the UseLargePagesIndividualAllocation flag is set (set by default on WS2003)
3000   // 2) NUMA Interleaving is enabled, in which case we use a different node for each page
3001   if (UseLargePagesIndividualAllocation || UseNUMAInterleaving) {
3002     log_debug(pagesize)("Reserving large pages individually.");
3003 
3004     char * p_buf = allocate_pages_individually(bytes, addr, flags, prot, LargePagesIndividualAllocationInjectError);
3005     if (p_buf == NULL) {
3006       // give an appropriate warning message
3007       if (UseNUMAInterleaving) {
3008         warning("NUMA large page allocation failed, UseLargePages flag ignored");
3009       }
3010       if (UseLargePagesIndividualAllocation) {
3011         warning("Individually allocated large pages failed, "
3012                 "use -XX:-UseLargePagesIndividualAllocation to turn off");
3013       }
3014       return NULL;
3015     }
3016 
3017     return p_buf;
3018 
3019   } else {
3020     log_debug(pagesize)("Reserving large pages in a single large chunk.");
3021 
3022     // normal policy just allocate it all at once
3023     DWORD flag = MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES;
3024     char * res = (char *)VirtualAlloc(addr, bytes, flag, prot);
3025     if (res != NULL) {
3026       MemTracker::record_virtual_memory_reserve_and_commit((address)res, bytes, CALLER_PC);
3027     }
3028 
3029     return res;
3030   }
3031 }
3032 
3033 bool os::release_memory_special(char* base, size_t bytes) {
3034   assert(base != NULL, "Sanity check");
3035   return release_memory(base, bytes);
3036 }
3037 
3038 void os::print_statistics() {
3039 }
3040 
3041 static void warn_fail_commit_memory(char* addr, size_t bytes, bool exec) {
3042   int err = os::get_last_error();
3043   char buf[256];
3044   size_t buf_len = os::lasterror(buf, sizeof(buf));
3045   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
3046           ", %d) failed; error='%s' (DOS error/errno=%d)", addr, bytes,
3047           exec, buf_len != 0 ? buf : "<no_error_string>", err);
3048 }
3049 
3050 bool os::pd_commit_memory(char* addr, size_t bytes, bool exec) {
3051   if (bytes == 0) {
3052     // Don't bother the OS with noops.
3053     return true;
3054   }
3055   assert((size_t) addr % os::vm_page_size() == 0, "commit on page boundaries");
3056   assert(bytes % os::vm_page_size() == 0, "commit in page-sized chunks");
3057   // Don't attempt to print anything if the OS call fails. We're
3058   // probably low on resources, so the print itself may cause crashes.
3059 
3060   // unless we have NUMAInterleaving enabled, the range of a commit
3061   // is always within a reserve covered by a single VirtualAlloc
3062   // in that case we can just do a single commit for the requested size
3063   if (!UseNUMAInterleaving) {
3064     if (VirtualAlloc(addr, bytes, MEM_COMMIT, PAGE_READWRITE) == NULL) {
3065       NOT_PRODUCT(warn_fail_commit_memory(addr, bytes, exec);)
3066       return false;
3067     }
3068     if (exec) {
3069       DWORD oldprot;
3070       // Windows doc says to use VirtualProtect to get execute permissions
3071       if (!VirtualProtect(addr, bytes, PAGE_EXECUTE_READWRITE, &oldprot)) {
3072         NOT_PRODUCT(warn_fail_commit_memory(addr, bytes, exec);)
3073         return false;
3074       }
3075     }
3076     return true;
3077   } else {
3078 
3079     // when NUMAInterleaving is enabled, the commit might cover a range that
3080     // came from multiple VirtualAlloc reserves (using allocate_pages_individually).
3081     // VirtualQuery can help us determine that.  The RegionSize that VirtualQuery
3082     // returns represents the number of bytes that can be committed in one step.
3083     size_t bytes_remaining = bytes;
3084     char * next_alloc_addr = addr;
3085     while (bytes_remaining > 0) {
3086       MEMORY_BASIC_INFORMATION alloc_info;
3087       VirtualQuery(next_alloc_addr, &alloc_info, sizeof(alloc_info));
3088       size_t bytes_to_rq = MIN2(bytes_remaining, (size_t)alloc_info.RegionSize);
3089       if (VirtualAlloc(next_alloc_addr, bytes_to_rq, MEM_COMMIT,
3090                        PAGE_READWRITE) == NULL) {
3091         NOT_PRODUCT(warn_fail_commit_memory(next_alloc_addr, bytes_to_rq,
3092                                             exec);)
3093         return false;
3094       }
3095       if (exec) {
3096         DWORD oldprot;
3097         if (!VirtualProtect(next_alloc_addr, bytes_to_rq,
3098                             PAGE_EXECUTE_READWRITE, &oldprot)) {
3099           NOT_PRODUCT(warn_fail_commit_memory(next_alloc_addr, bytes_to_rq,
3100                                               exec);)
3101           return false;
3102         }
3103       }
3104       bytes_remaining -= bytes_to_rq;
3105       next_alloc_addr += bytes_to_rq;
3106     }
3107   }
3108   // if we made it this far, return true
3109   return true;
3110 }
3111 
3112 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
3113                           bool exec) {
3114   // alignment_hint is ignored on this OS
3115   return pd_commit_memory(addr, size, exec);
3116 }
3117 
3118 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
3119                                   const char* mesg) {
3120   assert(mesg != NULL, "mesg must be specified");
3121   if (!pd_commit_memory(addr, size, exec)) {
3122     warn_fail_commit_memory(addr, size, exec);
3123     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
3124   }
3125 }
3126 
3127 void os::pd_commit_memory_or_exit(char* addr, size_t size,
3128                                   size_t alignment_hint, bool exec,
3129                                   const char* mesg) {
3130   // alignment_hint is ignored on this OS
3131   pd_commit_memory_or_exit(addr, size, exec, mesg);
3132 }
3133 
3134 bool os::pd_uncommit_memory(char* addr, size_t bytes) {
3135   if (bytes == 0) {
3136     // Don't bother the OS with noops.
3137     return true;
3138   }
3139   assert((size_t) addr % os::vm_page_size() == 0, "uncommit on page boundaries");
3140   assert(bytes % os::vm_page_size() == 0, "uncommit in page-sized chunks");
3141   return (VirtualFree(addr, bytes, MEM_DECOMMIT) != 0);
3142 }
3143 
3144 bool os::pd_release_memory(char* addr, size_t bytes) {
3145   return VirtualFree(addr, 0, MEM_RELEASE) != 0;
3146 }
3147 
3148 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
3149   return os::commit_memory(addr, size, !ExecMem);
3150 }
3151 
3152 bool os::remove_stack_guard_pages(char* addr, size_t size) {
3153   return os::uncommit_memory(addr, size);
3154 }
3155 
3156 static bool protect_pages_individually(char* addr, size_t bytes, unsigned int p, DWORD *old_status) {
3157   uint count = 0;
3158   bool ret = false;
3159   size_t bytes_remaining = bytes;
3160   char * next_protect_addr = addr;
3161 
3162   // Use VirtualQuery() to get the chunk size.
3163   while (bytes_remaining) {
3164     MEMORY_BASIC_INFORMATION alloc_info;
3165     if (VirtualQuery(next_protect_addr, &alloc_info, sizeof(alloc_info)) == 0) {
3166       return false;
3167     }
3168 
3169     size_t bytes_to_protect = MIN2(bytes_remaining, (size_t)alloc_info.RegionSize);
3170     // We used different API at allocate_pages_individually() based on UseNUMAInterleaving,
3171     // but we don't distinguish here as both cases are protected by same API.
3172     ret = VirtualProtect(next_protect_addr, bytes_to_protect, p, old_status) != 0;
3173     warning("Failed protecting pages individually for chunk #%u", count);
3174     if (!ret) {
3175       return false;
3176     }
3177 
3178     bytes_remaining -= bytes_to_protect;
3179     next_protect_addr += bytes_to_protect;
3180     count++;
3181   }
3182   return ret;
3183 }
3184 
3185 // Set protections specified
3186 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
3187                         bool is_committed) {
3188   unsigned int p = 0;
3189   switch (prot) {
3190   case MEM_PROT_NONE: p = PAGE_NOACCESS; break;
3191   case MEM_PROT_READ: p = PAGE_READONLY; break;
3192   case MEM_PROT_RW:   p = PAGE_READWRITE; break;
3193   case MEM_PROT_RWX:  p = PAGE_EXECUTE_READWRITE; break;
3194   default:
3195     ShouldNotReachHere();
3196   }
3197 
3198   DWORD old_status;
3199 
3200   // Strange enough, but on Win32 one can change protection only for committed
3201   // memory, not a big deal anyway, as bytes less or equal than 64K
3202   if (!is_committed) {
3203     commit_memory_or_exit(addr, bytes, prot == MEM_PROT_RWX,
3204                           "cannot commit protection page");
3205   }
3206   // One cannot use os::guard_memory() here, as on Win32 guard page
3207   // have different (one-shot) semantics, from MSDN on PAGE_GUARD:
3208   //
3209   // Pages in the region become guard pages. Any attempt to access a guard page
3210   // causes the system to raise a STATUS_GUARD_PAGE exception and turn off
3211   // the guard page status. Guard pages thus act as a one-time access alarm.
3212   bool ret;
3213   if (UseNUMAInterleaving) {
3214     // If UseNUMAInterleaving is enabled, the pages may have been allocated a chunk at a time,
3215     // so we must protect the chunks individually.
3216     ret = protect_pages_individually(addr, bytes, p, &old_status);
3217   } else {
3218     ret = VirtualProtect(addr, bytes, p, &old_status) != 0;
3219   }
3220 #ifdef ASSERT
3221   if (!ret) {
3222     int err = os::get_last_error();
3223     char buf[256];
3224     size_t buf_len = os::lasterror(buf, sizeof(buf));
3225     warning("INFO: os::protect_memory(" PTR_FORMAT ", " SIZE_FORMAT
3226           ") failed; error='%s' (DOS error/errno=%d)", addr, bytes,
3227           buf_len != 0 ? buf : "<no_error_string>", err);
3228   }
3229 #endif
3230   return ret;
3231 }
3232 
3233 bool os::guard_memory(char* addr, size_t bytes) {
3234   DWORD old_status;
3235   return VirtualProtect(addr, bytes, PAGE_READWRITE | PAGE_GUARD, &old_status) != 0;
3236 }
3237 
3238 bool os::unguard_memory(char* addr, size_t bytes) {
3239   DWORD old_status;
3240   return VirtualProtect(addr, bytes, PAGE_READWRITE, &old_status) != 0;
3241 }
3242 
3243 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { }
3244 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { }
3245 void os::numa_make_global(char *addr, size_t bytes)    { }
3246 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint)    { }
3247 bool os::numa_topology_changed()                       { return false; }
3248 size_t os::numa_get_groups_num()                       { return MAX2(numa_node_list_holder.get_count(), 1); }
3249 int os::numa_get_group_id()                            { return 0; }
3250 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
3251   if (numa_node_list_holder.get_count() == 0 && size > 0) {
3252     // Provide an answer for UMA systems
3253     ids[0] = 0;
3254     return 1;
3255   } else {
3256     // check for size bigger than actual groups_num
3257     size = MIN2(size, numa_get_groups_num());
3258     for (int i = 0; i < (int)size; i++) {
3259       ids[i] = numa_node_list_holder.get_node_list_entry(i);
3260     }
3261     return size;
3262   }
3263 }
3264 
3265 bool os::get_page_info(char *start, page_info* info) {
3266   return false;
3267 }
3268 
3269 char *os::scan_pages(char *start, char* end, page_info* page_expected,
3270                      page_info* page_found) {
3271   return end;
3272 }
3273 
3274 char* os::non_memory_address_word() {
3275   // Must never look like an address returned by reserve_memory,
3276   // even in its subfields (as defined by the CPU immediate fields,
3277   // if the CPU splits constants across multiple instructions).
3278   return (char*)-1;
3279 }
3280 
3281 #define MAX_ERROR_COUNT 100
3282 #define SYS_THREAD_ERROR 0xffffffffUL
3283 
3284 void os::pd_start_thread(Thread* thread) {
3285   DWORD ret = ResumeThread(thread->osthread()->thread_handle());
3286   // Returns previous suspend state:
3287   // 0:  Thread was not suspended
3288   // 1:  Thread is running now
3289   // >1: Thread is still suspended.
3290   assert(ret != SYS_THREAD_ERROR, "StartThread failed"); // should propagate back
3291 }
3292 
3293 class HighResolutionInterval : public CHeapObj<mtThread> {
3294   // The default timer resolution seems to be 10 milliseconds.
3295   // (Where is this written down?)
3296   // If someone wants to sleep for only a fraction of the default,
3297   // then we set the timer resolution down to 1 millisecond for
3298   // the duration of their interval.
3299   // We carefully set the resolution back, since otherwise we
3300   // seem to incur an overhead (3%?) that we don't need.
3301   // CONSIDER: if ms is small, say 3, then we should run with a high resolution time.
3302   // Buf if ms is large, say 500, or 503, we should avoid the call to timeBeginPeriod().
3303   // Alternatively, we could compute the relative error (503/500 = .6%) and only use
3304   // timeBeginPeriod() if the relative error exceeded some threshold.
3305   // timeBeginPeriod() has been linked to problems with clock drift on win32 systems and
3306   // to decreased efficiency related to increased timer "tick" rates.  We want to minimize
3307   // (a) calls to timeBeginPeriod() and timeEndPeriod() and (b) time spent with high
3308   // resolution timers running.
3309  private:
3310   jlong resolution;
3311  public:
3312   HighResolutionInterval(jlong ms) {
3313     resolution = ms % 10L;
3314     if (resolution != 0) {
3315       MMRESULT result = timeBeginPeriod(1L);
3316     }
3317   }
3318   ~HighResolutionInterval() {
3319     if (resolution != 0) {
3320       MMRESULT result = timeEndPeriod(1L);
3321     }
3322     resolution = 0L;
3323   }
3324 };
3325 
3326 int os::sleep(Thread* thread, jlong ms, bool interruptable) {
3327   jlong limit = (jlong) MAXDWORD;
3328 
3329   while (ms > limit) {
3330     int res;
3331     if ((res = sleep(thread, limit, interruptable)) != OS_TIMEOUT) {
3332       return res;
3333     }
3334     ms -= limit;
3335   }
3336 
3337   assert(thread == Thread::current(), "thread consistency check");
3338   OSThread* osthread = thread->osthread();
3339   OSThreadWaitState osts(osthread, false /* not Object.wait() */);
3340   int result;
3341   if (interruptable) {
3342     assert(thread->is_Java_thread(), "must be java thread");
3343     JavaThread *jt = (JavaThread *) thread;
3344     ThreadBlockInVM tbivm(jt);
3345 
3346     jt->set_suspend_equivalent();
3347     // cleared by handle_special_suspend_equivalent_condition() or
3348     // java_suspend_self() via check_and_wait_while_suspended()
3349 
3350     HANDLE events[1];
3351     events[0] = osthread->interrupt_event();
3352     HighResolutionInterval *phri=NULL;
3353     if (!ForceTimeHighResolution) {
3354       phri = new HighResolutionInterval(ms);
3355     }
3356     if (WaitForMultipleObjects(1, events, FALSE, (DWORD)ms) == WAIT_TIMEOUT) {
3357       result = OS_TIMEOUT;
3358     } else {
3359       ResetEvent(osthread->interrupt_event());
3360       osthread->set_interrupted(false);
3361       result = OS_INTRPT;
3362     }
3363     delete phri; //if it is NULL, harmless
3364 
3365     // were we externally suspended while we were waiting?
3366     jt->check_and_wait_while_suspended();
3367   } else {
3368     assert(!thread->is_Java_thread(), "must not be java thread");
3369     Sleep((long) ms);
3370     result = OS_TIMEOUT;
3371   }
3372   return result;
3373 }
3374 
3375 // Short sleep, direct OS call.
3376 //
3377 // ms = 0, means allow others (if any) to run.
3378 //
3379 void os::naked_short_sleep(jlong ms) {
3380   assert(ms < 1000, "Un-interruptable sleep, short time use only");
3381   Sleep(ms);
3382 }
3383 
3384 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
3385 void os::infinite_sleep() {
3386   while (true) {    // sleep forever ...
3387     Sleep(100000);  // ... 100 seconds at a time
3388   }
3389 }
3390 
3391 typedef BOOL (WINAPI * STTSignature)(void);
3392 
3393 void os::naked_yield() {
3394   // Consider passing back the return value from SwitchToThread().
3395   SwitchToThread();
3396 }
3397 
3398 // Win32 only gives you access to seven real priorities at a time,
3399 // so we compress Java's ten down to seven.  It would be better
3400 // if we dynamically adjusted relative priorities.
3401 
3402 int os::java_to_os_priority[CriticalPriority + 1] = {
3403   THREAD_PRIORITY_IDLE,                         // 0  Entry should never be used
3404   THREAD_PRIORITY_LOWEST,                       // 1  MinPriority
3405   THREAD_PRIORITY_LOWEST,                       // 2
3406   THREAD_PRIORITY_BELOW_NORMAL,                 // 3
3407   THREAD_PRIORITY_BELOW_NORMAL,                 // 4
3408   THREAD_PRIORITY_NORMAL,                       // 5  NormPriority
3409   THREAD_PRIORITY_NORMAL,                       // 6
3410   THREAD_PRIORITY_ABOVE_NORMAL,                 // 7
3411   THREAD_PRIORITY_ABOVE_NORMAL,                 // 8
3412   THREAD_PRIORITY_HIGHEST,                      // 9  NearMaxPriority
3413   THREAD_PRIORITY_HIGHEST,                      // 10 MaxPriority
3414   THREAD_PRIORITY_HIGHEST                       // 11 CriticalPriority
3415 };
3416 
3417 int prio_policy1[CriticalPriority + 1] = {
3418   THREAD_PRIORITY_IDLE,                         // 0  Entry should never be used
3419   THREAD_PRIORITY_LOWEST,                       // 1  MinPriority
3420   THREAD_PRIORITY_LOWEST,                       // 2
3421   THREAD_PRIORITY_BELOW_NORMAL,                 // 3
3422   THREAD_PRIORITY_BELOW_NORMAL,                 // 4
3423   THREAD_PRIORITY_NORMAL,                       // 5  NormPriority
3424   THREAD_PRIORITY_ABOVE_NORMAL,                 // 6
3425   THREAD_PRIORITY_ABOVE_NORMAL,                 // 7
3426   THREAD_PRIORITY_HIGHEST,                      // 8
3427   THREAD_PRIORITY_HIGHEST,                      // 9  NearMaxPriority
3428   THREAD_PRIORITY_TIME_CRITICAL,                // 10 MaxPriority
3429   THREAD_PRIORITY_TIME_CRITICAL                 // 11 CriticalPriority
3430 };
3431 
3432 static int prio_init() {
3433   // If ThreadPriorityPolicy is 1, switch tables
3434   if (ThreadPriorityPolicy == 1) {
3435     int i;
3436     for (i = 0; i < CriticalPriority + 1; i++) {
3437       os::java_to_os_priority[i] = prio_policy1[i];
3438     }
3439   }
3440   if (UseCriticalJavaThreadPriority) {
3441     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
3442   }
3443   return 0;
3444 }
3445 
3446 OSReturn os::set_native_priority(Thread* thread, int priority) {
3447   if (!UseThreadPriorities) return OS_OK;
3448   bool ret = SetThreadPriority(thread->osthread()->thread_handle(), priority) != 0;
3449   return ret ? OS_OK : OS_ERR;
3450 }
3451 
3452 OSReturn os::get_native_priority(const Thread* const thread,
3453                                  int* priority_ptr) {
3454   if (!UseThreadPriorities) {
3455     *priority_ptr = java_to_os_priority[NormPriority];
3456     return OS_OK;
3457   }
3458   int os_prio = GetThreadPriority(thread->osthread()->thread_handle());
3459   if (os_prio == THREAD_PRIORITY_ERROR_RETURN) {
3460     assert(false, "GetThreadPriority failed");
3461     return OS_ERR;
3462   }
3463   *priority_ptr = os_prio;
3464   return OS_OK;
3465 }
3466 
3467 
3468 // Hint to the underlying OS that a task switch would not be good.
3469 // Void return because it's a hint and can fail.
3470 void os::hint_no_preempt() {}
3471 
3472 void os::interrupt(Thread* thread) {
3473   assert(!thread->is_Java_thread() || Thread::current() == thread ||
3474          Threads_lock->owned_by_self(),
3475          "possibility of dangling Thread pointer");
3476 
3477   OSThread* osthread = thread->osthread();
3478   osthread->set_interrupted(true);
3479   // More than one thread can get here with the same value of osthread,
3480   // resulting in multiple notifications.  We do, however, want the store
3481   // to interrupted() to be visible to other threads before we post
3482   // the interrupt event.
3483   OrderAccess::release();
3484   SetEvent(osthread->interrupt_event());
3485   // For JSR166:  unpark after setting status
3486   if (thread->is_Java_thread()) {
3487     ((JavaThread*)thread)->parker()->unpark();
3488   }
3489 
3490   ParkEvent * ev = thread->_ParkEvent;
3491   if (ev != NULL) ev->unpark();
3492 }
3493 
3494 
3495 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
3496   assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
3497          "possibility of dangling Thread pointer");
3498 
3499   OSThread* osthread = thread->osthread();
3500   // There is no synchronization between the setting of the interrupt
3501   // and it being cleared here. It is critical - see 6535709 - that
3502   // we only clear the interrupt state, and reset the interrupt event,
3503   // if we are going to report that we were indeed interrupted - else
3504   // an interrupt can be "lost", leading to spurious wakeups or lost wakeups
3505   // depending on the timing. By checking thread interrupt event to see
3506   // if the thread gets real interrupt thus prevent spurious wakeup.
3507   bool interrupted = osthread->interrupted() && (WaitForSingleObject(osthread->interrupt_event(), 0) == WAIT_OBJECT_0);
3508   if (interrupted && clear_interrupted) {
3509     osthread->set_interrupted(false);
3510     ResetEvent(osthread->interrupt_event());
3511   } // Otherwise leave the interrupted state alone
3512 
3513   return interrupted;
3514 }
3515 
3516 // GetCurrentThreadId() returns DWORD
3517 intx os::current_thread_id()  { return GetCurrentThreadId(); }
3518 
3519 static int _initial_pid = 0;
3520 
3521 int os::current_process_id() {
3522   return (_initial_pid ? _initial_pid : _getpid());
3523 }
3524 
3525 int    os::win32::_vm_page_size              = 0;
3526 int    os::win32::_vm_allocation_granularity = 0;
3527 int    os::win32::_processor_type            = 0;
3528 // Processor level is not available on non-NT systems, use vm_version instead
3529 int    os::win32::_processor_level           = 0;
3530 julong os::win32::_physical_memory           = 0;
3531 size_t os::win32::_default_stack_size        = 0;
3532 
3533 intx          os::win32::_os_thread_limit    = 0;
3534 volatile intx os::win32::_os_thread_count    = 0;
3535 
3536 bool   os::win32::_is_windows_server         = false;
3537 
3538 // 6573254
3539 // Currently, the bug is observed across all the supported Windows releases,
3540 // including the latest one (as of this writing - Windows Server 2012 R2)
3541 bool   os::win32::_has_exit_bug              = true;
3542 
3543 void os::win32::initialize_system_info() {
3544   SYSTEM_INFO si;
3545   GetSystemInfo(&si);
3546   _vm_page_size    = si.dwPageSize;
3547   _vm_allocation_granularity = si.dwAllocationGranularity;
3548   _processor_type  = si.dwProcessorType;
3549   _processor_level = si.wProcessorLevel;
3550   set_processor_count(si.dwNumberOfProcessors);
3551 
3552   MEMORYSTATUSEX ms;
3553   ms.dwLength = sizeof(ms);
3554 
3555   // also returns dwAvailPhys (free physical memory bytes), dwTotalVirtual, dwAvailVirtual,
3556   // dwMemoryLoad (% of memory in use)
3557   GlobalMemoryStatusEx(&ms);
3558   _physical_memory = ms.ullTotalPhys;
3559 
3560   if (FLAG_IS_DEFAULT(MaxRAM)) {
3561     // Adjust MaxRAM according to the maximum virtual address space available.
3562     FLAG_SET_DEFAULT(MaxRAM, MIN2(MaxRAM, (uint64_t) ms.ullTotalVirtual));
3563   }
3564 
3565   OSVERSIONINFOEX oi;
3566   oi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
3567   GetVersionEx((OSVERSIONINFO*)&oi);
3568   switch (oi.dwPlatformId) {
3569   case VER_PLATFORM_WIN32_NT:
3570     {
3571       int os_vers = oi.dwMajorVersion * 1000 + oi.dwMinorVersion;
3572       if (oi.wProductType == VER_NT_DOMAIN_CONTROLLER ||
3573           oi.wProductType == VER_NT_SERVER) {
3574         _is_windows_server = true;
3575       }
3576     }
3577     break;
3578   default: fatal("Unknown platform");
3579   }
3580 
3581   _default_stack_size = os::current_stack_size();
3582   assert(_default_stack_size > (size_t) _vm_page_size, "invalid stack size");
3583   assert((_default_stack_size & (_vm_page_size - 1)) == 0,
3584          "stack size not a multiple of page size");
3585 
3586   initialize_performance_counter();
3587 }
3588 
3589 
3590 HINSTANCE os::win32::load_Windows_dll(const char* name, char *ebuf,
3591                                       int ebuflen) {
3592   char path[MAX_PATH];
3593   DWORD size;
3594   DWORD pathLen = (DWORD)sizeof(path);
3595   HINSTANCE result = NULL;
3596 
3597   // only allow library name without path component
3598   assert(strchr(name, '\\') == NULL, "path not allowed");
3599   assert(strchr(name, ':') == NULL, "path not allowed");
3600   if (strchr(name, '\\') != NULL || strchr(name, ':') != NULL) {
3601     jio_snprintf(ebuf, ebuflen,
3602                  "Invalid parameter while calling os::win32::load_windows_dll(): cannot take path: %s", name);
3603     return NULL;
3604   }
3605 
3606   // search system directory
3607   if ((size = GetSystemDirectory(path, pathLen)) > 0) {
3608     if (size >= pathLen) {
3609       return NULL; // truncated
3610     }
3611     if (jio_snprintf(path + size, pathLen - size, "\\%s", name) == -1) {
3612       return NULL; // truncated
3613     }
3614     if ((result = (HINSTANCE)os::dll_load(path, ebuf, ebuflen)) != NULL) {
3615       return result;
3616     }
3617   }
3618 
3619   // try Windows directory
3620   if ((size = GetWindowsDirectory(path, pathLen)) > 0) {
3621     if (size >= pathLen) {
3622       return NULL; // truncated
3623     }
3624     if (jio_snprintf(path + size, pathLen - size, "\\%s", name) == -1) {
3625       return NULL; // truncated
3626     }
3627     if ((result = (HINSTANCE)os::dll_load(path, ebuf, ebuflen)) != NULL) {
3628       return result;
3629     }
3630   }
3631 
3632   jio_snprintf(ebuf, ebuflen,
3633                "os::win32::load_windows_dll() cannot load %s from system directories.", name);
3634   return NULL;
3635 }
3636 
3637 #define MAXIMUM_THREADS_TO_KEEP (16 * MAXIMUM_WAIT_OBJECTS)
3638 #define EXIT_TIMEOUT 300000 /* 5 minutes */
3639 
3640 static BOOL CALLBACK init_crit_sect_call(PINIT_ONCE, PVOID pcrit_sect, PVOID*) {
3641   InitializeCriticalSection((CRITICAL_SECTION*)pcrit_sect);
3642   return TRUE;
3643 }
3644 
3645 int os::win32::exit_process_or_thread(Ept what, int exit_code) {
3646   // Basic approach:
3647   //  - Each exiting thread registers its intent to exit and then does so.
3648   //  - A thread trying to terminate the process must wait for all
3649   //    threads currently exiting to complete their exit.
3650 
3651   if (os::win32::has_exit_bug()) {
3652     // The array holds handles of the threads that have started exiting by calling
3653     // _endthreadex().
3654     // Should be large enough to avoid blocking the exiting thread due to lack of
3655     // a free slot.
3656     static HANDLE handles[MAXIMUM_THREADS_TO_KEEP];
3657     static int handle_count = 0;
3658 
3659     static INIT_ONCE init_once_crit_sect = INIT_ONCE_STATIC_INIT;
3660     static CRITICAL_SECTION crit_sect;
3661     static volatile jint process_exiting = 0;
3662     int i, j;
3663     DWORD res;
3664     HANDLE hproc, hthr;
3665 
3666     // We only attempt to register threads until a process exiting
3667     // thread manages to set the process_exiting flag. Any threads
3668     // that come through here after the process_exiting flag is set
3669     // are unregistered and will be caught in the SuspendThread()
3670     // infinite loop below.
3671     bool registered = false;
3672 
3673     // The first thread that reached this point, initializes the critical section.
3674     if (!InitOnceExecuteOnce(&init_once_crit_sect, init_crit_sect_call, &crit_sect, NULL)) {
3675       warning("crit_sect initialization failed in %s: %d\n", __FILE__, __LINE__);
3676     } else if (OrderAccess::load_acquire(&process_exiting) == 0) {
3677       if (what != EPT_THREAD) {
3678         // Atomically set process_exiting before the critical section
3679         // to increase the visibility between racing threads.
3680         Atomic::cmpxchg((jint)GetCurrentThreadId(), &process_exiting, 0);
3681       }
3682       EnterCriticalSection(&crit_sect);
3683 
3684       if (what == EPT_THREAD && OrderAccess::load_acquire(&process_exiting) == 0) {
3685         // Remove from the array those handles of the threads that have completed exiting.
3686         for (i = 0, j = 0; i < handle_count; ++i) {
3687           res = WaitForSingleObject(handles[i], 0 /* don't wait */);
3688           if (res == WAIT_TIMEOUT) {
3689             handles[j++] = handles[i];
3690           } else {
3691             if (res == WAIT_FAILED) {
3692               warning("WaitForSingleObject failed (%u) in %s: %d\n",
3693                       GetLastError(), __FILE__, __LINE__);
3694             }
3695             // Don't keep the handle, if we failed waiting for it.
3696             CloseHandle(handles[i]);
3697           }
3698         }
3699 
3700         // If there's no free slot in the array of the kept handles, we'll have to
3701         // wait until at least one thread completes exiting.
3702         if ((handle_count = j) == MAXIMUM_THREADS_TO_KEEP) {
3703           // Raise the priority of the oldest exiting thread to increase its chances
3704           // to complete sooner.
3705           SetThreadPriority(handles[0], THREAD_PRIORITY_ABOVE_NORMAL);
3706           res = WaitForMultipleObjects(MAXIMUM_WAIT_OBJECTS, handles, FALSE, EXIT_TIMEOUT);
3707           if (res >= WAIT_OBJECT_0 && res < (WAIT_OBJECT_0 + MAXIMUM_WAIT_OBJECTS)) {
3708             i = (res - WAIT_OBJECT_0);
3709             handle_count = MAXIMUM_THREADS_TO_KEEP - 1;
3710             for (; i < handle_count; ++i) {
3711               handles[i] = handles[i + 1];
3712             }
3713           } else {
3714             warning("WaitForMultipleObjects %s (%u) in %s: %d\n",
3715                     (res == WAIT_FAILED ? "failed" : "timed out"),
3716                     GetLastError(), __FILE__, __LINE__);
3717             // Don't keep handles, if we failed waiting for them.
3718             for (i = 0; i < MAXIMUM_THREADS_TO_KEEP; ++i) {
3719               CloseHandle(handles[i]);
3720             }
3721             handle_count = 0;
3722           }
3723         }
3724 
3725         // Store a duplicate of the current thread handle in the array of handles.
3726         hproc = GetCurrentProcess();
3727         hthr = GetCurrentThread();
3728         if (!DuplicateHandle(hproc, hthr, hproc, &handles[handle_count],
3729                              0, FALSE, DUPLICATE_SAME_ACCESS)) {
3730           warning("DuplicateHandle failed (%u) in %s: %d\n",
3731                   GetLastError(), __FILE__, __LINE__);
3732 
3733           // We can't register this thread (no more handles) so this thread
3734           // may be racing with a thread that is calling exit(). If the thread
3735           // that is calling exit() has managed to set the process_exiting
3736           // flag, then this thread will be caught in the SuspendThread()
3737           // infinite loop below which closes that race. A small timing
3738           // window remains before the process_exiting flag is set, but it
3739           // is only exposed when we are out of handles.
3740         } else {
3741           ++handle_count;
3742           registered = true;
3743 
3744           // The current exiting thread has stored its handle in the array, and now
3745           // should leave the critical section before calling _endthreadex().
3746         }
3747 
3748       } else if (what != EPT_THREAD && handle_count > 0) {
3749         jlong start_time, finish_time, timeout_left;
3750         // Before ending the process, make sure all the threads that had called
3751         // _endthreadex() completed.
3752 
3753         // Set the priority level of the current thread to the same value as
3754         // the priority level of exiting threads.
3755         // This is to ensure it will be given a fair chance to execute if
3756         // the timeout expires.
3757         hthr = GetCurrentThread();
3758         SetThreadPriority(hthr, THREAD_PRIORITY_ABOVE_NORMAL);
3759         start_time = os::javaTimeNanos();
3760         finish_time = start_time + ((jlong)EXIT_TIMEOUT * 1000000L);
3761         for (i = 0; ; ) {
3762           int portion_count = handle_count - i;
3763           if (portion_count > MAXIMUM_WAIT_OBJECTS) {
3764             portion_count = MAXIMUM_WAIT_OBJECTS;
3765           }
3766           for (j = 0; j < portion_count; ++j) {
3767             SetThreadPriority(handles[i + j], THREAD_PRIORITY_ABOVE_NORMAL);
3768           }
3769           timeout_left = (finish_time - start_time) / 1000000L;
3770           if (timeout_left < 0) {
3771             timeout_left = 0;
3772           }
3773           res = WaitForMultipleObjects(portion_count, handles + i, TRUE, timeout_left);
3774           if (res == WAIT_FAILED || res == WAIT_TIMEOUT) {
3775             warning("WaitForMultipleObjects %s (%u) in %s: %d\n",
3776                     (res == WAIT_FAILED ? "failed" : "timed out"),
3777                     GetLastError(), __FILE__, __LINE__);
3778             // Reset portion_count so we close the remaining
3779             // handles due to this error.
3780             portion_count = handle_count - i;
3781           }
3782           for (j = 0; j < portion_count; ++j) {
3783             CloseHandle(handles[i + j]);
3784           }
3785           if ((i += portion_count) >= handle_count) {
3786             break;
3787           }
3788           start_time = os::javaTimeNanos();
3789         }
3790         handle_count = 0;
3791       }
3792 
3793       LeaveCriticalSection(&crit_sect);
3794     }
3795 
3796     if (!registered &&
3797         OrderAccess::load_acquire(&process_exiting) != 0 &&
3798         process_exiting != (jint)GetCurrentThreadId()) {
3799       // Some other thread is about to call exit(), so we don't let
3800       // the current unregistered thread proceed to exit() or _endthreadex()
3801       while (true) {
3802         SuspendThread(GetCurrentThread());
3803         // Avoid busy-wait loop, if SuspendThread() failed.
3804         Sleep(EXIT_TIMEOUT);
3805       }
3806     }
3807   }
3808 
3809   // We are here if either
3810   // - there's no 'race at exit' bug on this OS release;
3811   // - initialization of the critical section failed (unlikely);
3812   // - the current thread has registered itself and left the critical section;
3813   // - the process-exiting thread has raised the flag and left the critical section.
3814   if (what == EPT_THREAD) {
3815     _endthreadex((unsigned)exit_code);
3816   } else if (what == EPT_PROCESS) {
3817     ::exit(exit_code);
3818   } else {
3819     _exit(exit_code);
3820   }
3821 
3822   // Should not reach here
3823   return exit_code;
3824 }
3825 
3826 #undef EXIT_TIMEOUT
3827 
3828 void os::win32::setmode_streams() {
3829   _setmode(_fileno(stdin), _O_BINARY);
3830   _setmode(_fileno(stdout), _O_BINARY);
3831   _setmode(_fileno(stderr), _O_BINARY);
3832 }
3833 
3834 
3835 bool os::is_debugger_attached() {
3836   return IsDebuggerPresent() ? true : false;
3837 }
3838 
3839 
3840 void os::wait_for_keypress_at_exit(void) {
3841   if (PauseAtExit) {
3842     fprintf(stderr, "Press any key to continue...\n");
3843     fgetc(stdin);
3844   }
3845 }
3846 
3847 
3848 bool os::message_box(const char* title, const char* message) {
3849   int result = MessageBox(NULL, message, title,
3850                           MB_YESNO | MB_ICONERROR | MB_SYSTEMMODAL | MB_DEFAULT_DESKTOP_ONLY);
3851   return result == IDYES;
3852 }
3853 
3854 #ifndef PRODUCT
3855 #ifndef _WIN64
3856 // Helpers to check whether NX protection is enabled
3857 int nx_exception_filter(_EXCEPTION_POINTERS *pex) {
3858   if (pex->ExceptionRecord->ExceptionCode == EXCEPTION_ACCESS_VIOLATION &&
3859       pex->ExceptionRecord->NumberParameters > 0 &&
3860       pex->ExceptionRecord->ExceptionInformation[0] ==
3861       EXCEPTION_INFO_EXEC_VIOLATION) {
3862     return EXCEPTION_EXECUTE_HANDLER;
3863   }
3864   return EXCEPTION_CONTINUE_SEARCH;
3865 }
3866 
3867 void nx_check_protection() {
3868   // If NX is enabled we'll get an exception calling into code on the stack
3869   char code[] = { (char)0xC3 }; // ret
3870   void *code_ptr = (void *)code;
3871   __try {
3872     __asm call code_ptr
3873   } __except(nx_exception_filter((_EXCEPTION_POINTERS*)_exception_info())) {
3874     tty->print_raw_cr("NX protection detected.");
3875   }
3876 }
3877 #endif // _WIN64
3878 #endif // PRODUCT
3879 
3880 // This is called _before_ the global arguments have been parsed
3881 void os::init(void) {
3882   _initial_pid = _getpid();
3883 
3884   init_random(1234567);
3885 
3886   win32::initialize_system_info();
3887   win32::setmode_streams();
3888   init_page_sizes((size_t) win32::vm_page_size());
3889 
3890   // This may be overridden later when argument processing is done.
3891   FLAG_SET_ERGO(bool, UseLargePagesIndividualAllocation, false);
3892 
3893   // Initialize main_process and main_thread
3894   main_process = GetCurrentProcess();  // Remember main_process is a pseudo handle
3895   if (!DuplicateHandle(main_process, GetCurrentThread(), main_process,
3896                        &main_thread, THREAD_ALL_ACCESS, false, 0)) {
3897     fatal("DuplicateHandle failed\n");
3898   }
3899   main_thread_id = (int) GetCurrentThreadId();
3900 
3901   // initialize fast thread access - only used for 32-bit
3902   win32::initialize_thread_ptr_offset();
3903 }
3904 
3905 // To install functions for atexit processing
3906 extern "C" {
3907   static void perfMemory_exit_helper() {
3908     perfMemory_exit();
3909   }
3910 }
3911 
3912 static jint initSock();
3913 
3914 // this is called _after_ the global arguments have been parsed
3915 jint os::init_2(void) {
3916   // Allocate a single page and mark it as readable for safepoint polling
3917   address polling_page = (address)VirtualAlloc(NULL, os::vm_page_size(), MEM_RESERVE, PAGE_READONLY);
3918   guarantee(polling_page != NULL, "Reserve Failed for polling page");
3919 
3920   address return_page  = (address)VirtualAlloc(polling_page, os::vm_page_size(), MEM_COMMIT, PAGE_READONLY);
3921   guarantee(return_page != NULL, "Commit Failed for polling page");
3922 
3923   os::set_polling_page(polling_page);
3924   log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(polling_page));
3925 
3926   if (!UseMembar) {
3927     address mem_serialize_page = (address)VirtualAlloc(NULL, os::vm_page_size(), MEM_RESERVE, PAGE_READWRITE);
3928     guarantee(mem_serialize_page != NULL, "Reserve Failed for memory serialize page");
3929 
3930     return_page  = (address)VirtualAlloc(mem_serialize_page, os::vm_page_size(), MEM_COMMIT, PAGE_READWRITE);
3931     guarantee(return_page != NULL, "Commit Failed for memory serialize page");
3932 
3933     os::set_memory_serialize_page(mem_serialize_page);
3934     log_info(os)("Memory Serialize Page address: " INTPTR_FORMAT, p2i(mem_serialize_page));
3935   }
3936 
3937   // Setup Windows Exceptions
3938 
3939   // for debugging float code generation bugs
3940   if (ForceFloatExceptions) {
3941 #ifndef  _WIN64
3942     static long fp_control_word = 0;
3943     __asm { fstcw fp_control_word }
3944     // see Intel PPro Manual, Vol. 2, p 7-16
3945     const long precision = 0x20;
3946     const long underflow = 0x10;
3947     const long overflow  = 0x08;
3948     const long zero_div  = 0x04;
3949     const long denorm    = 0x02;
3950     const long invalid   = 0x01;
3951     fp_control_word |= invalid;
3952     __asm { fldcw fp_control_word }
3953 #endif
3954   }
3955 
3956   // If stack_commit_size is 0, windows will reserve the default size,
3957   // but only commit a small portion of it.
3958   size_t stack_commit_size = align_up(ThreadStackSize*K, os::vm_page_size());
3959   size_t default_reserve_size = os::win32::default_stack_size();
3960   size_t actual_reserve_size = stack_commit_size;
3961   if (stack_commit_size < default_reserve_size) {
3962     // If stack_commit_size == 0, we want this too
3963     actual_reserve_size = default_reserve_size;
3964   }
3965 
3966   // Check minimum allowable stack size for thread creation and to initialize
3967   // the java system classes, including StackOverflowError - depends on page
3968   // size.  Add two 4K pages for compiler2 recursion in main thread.
3969   // Add in 4*BytesPerWord 4K pages to account for VM stack during
3970   // class initialization depending on 32 or 64 bit VM.
3971   size_t min_stack_allowed =
3972             (size_t)(JavaThread::stack_guard_zone_size() +
3973                      JavaThread::stack_shadow_zone_size() +
3974                      (4*BytesPerWord COMPILER2_PRESENT(+2)) * 4 * K);
3975 
3976   min_stack_allowed = align_up(min_stack_allowed, os::vm_page_size());
3977 
3978   if (actual_reserve_size < min_stack_allowed) {
3979     tty->print_cr("\nThe Java thread stack size specified is too small. "
3980                   "Specify at least %dk",
3981                   min_stack_allowed / K);
3982     return JNI_ERR;
3983   }
3984 
3985   JavaThread::set_stack_size_at_create(stack_commit_size);
3986 
3987   // Calculate theoretical max. size of Threads to guard gainst artifical
3988   // out-of-memory situations, where all available address-space has been
3989   // reserved by thread stacks.
3990   assert(actual_reserve_size != 0, "Must have a stack");
3991 
3992   // Calculate the thread limit when we should start doing Virtual Memory
3993   // banging. Currently when the threads will have used all but 200Mb of space.
3994   //
3995   // TODO: consider performing a similar calculation for commit size instead
3996   // as reserve size, since on a 64-bit platform we'll run into that more
3997   // often than running out of virtual memory space.  We can use the
3998   // lower value of the two calculations as the os_thread_limit.
3999   size_t max_address_space = ((size_t)1 << (BitsPerWord - 1)) - (200 * K * K);
4000   win32::_os_thread_limit = (intx)(max_address_space / actual_reserve_size);
4001 
4002   // at exit methods are called in the reverse order of their registration.
4003   // there is no limit to the number of functions registered. atexit does
4004   // not set errno.
4005 
4006   if (PerfAllowAtExitRegistration) {
4007     // only register atexit functions if PerfAllowAtExitRegistration is set.
4008     // atexit functions can be delayed until process exit time, which
4009     // can be problematic for embedded VM situations. Embedded VMs should
4010     // call DestroyJavaVM() to assure that VM resources are released.
4011 
4012     // note: perfMemory_exit_helper atexit function may be removed in
4013     // the future if the appropriate cleanup code can be added to the
4014     // VM_Exit VMOperation's doit method.
4015     if (atexit(perfMemory_exit_helper) != 0) {
4016       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
4017     }
4018   }
4019 
4020 #ifndef _WIN64
4021   // Print something if NX is enabled (win32 on AMD64)
4022   NOT_PRODUCT(if (PrintMiscellaneous && Verbose) nx_check_protection());
4023 #endif
4024 
4025   // initialize thread priority policy
4026   prio_init();
4027 
4028   if (UseNUMA && !ForceNUMA) {
4029     UseNUMA = false; // We don't fully support this yet
4030   }
4031 
4032   if (UseNUMAInterleaving) {
4033     // first check whether this Windows OS supports VirtualAllocExNuma, if not ignore this flag
4034     bool success = numa_interleaving_init();
4035     if (!success) UseNUMAInterleaving = false;
4036   }
4037 
4038   if (initSock() != JNI_OK) {
4039     return JNI_ERR;
4040   }
4041 
4042   if (InitializeDbgHelpEarly) {
4043     SymbolEngine::recalc_search_path();
4044   }
4045 
4046   return JNI_OK;
4047 }
4048 
4049 // Mark the polling page as unreadable
4050 void os::make_polling_page_unreadable(void) {
4051   DWORD old_status;
4052   if (!VirtualProtect((char *)_polling_page, os::vm_page_size(),
4053                       PAGE_NOACCESS, &old_status)) {
4054     fatal("Could not disable polling page");
4055   }
4056 }
4057 
4058 // Mark the polling page as readable
4059 void os::make_polling_page_readable(void) {
4060   DWORD old_status;
4061   if (!VirtualProtect((char *)_polling_page, os::vm_page_size(),
4062                       PAGE_READONLY, &old_status)) {
4063     fatal("Could not enable polling page");
4064   }
4065 }
4066 
4067 
4068 int os::stat(const char *path, struct stat *sbuf) {
4069   char pathbuf[MAX_PATH];
4070   if (strlen(path) > MAX_PATH - 1) {
4071     errno = ENAMETOOLONG;
4072     return -1;
4073   }
4074   os::native_path(strcpy(pathbuf, path));
4075   int ret = ::stat(pathbuf, sbuf);
4076   if (sbuf != NULL && UseUTCFileTimestamp) {
4077     // Fix for 6539723.  st_mtime returned from stat() is dependent on
4078     // the system timezone and so can return different values for the
4079     // same file if/when daylight savings time changes.  This adjustment
4080     // makes sure the same timestamp is returned regardless of the TZ.
4081     //
4082     // See:
4083     // http://msdn.microsoft.com/library/
4084     //   default.asp?url=/library/en-us/sysinfo/base/
4085     //   time_zone_information_str.asp
4086     // and
4087     // http://msdn.microsoft.com/library/default.asp?url=
4088     //   /library/en-us/sysinfo/base/settimezoneinformation.asp
4089     //
4090     // NOTE: there is a insidious bug here:  If the timezone is changed
4091     // after the call to stat() but before 'GetTimeZoneInformation()', then
4092     // the adjustment we do here will be wrong and we'll return the wrong
4093     // value (which will likely end up creating an invalid class data
4094     // archive).  Absent a better API for this, or some time zone locking
4095     // mechanism, we'll have to live with this risk.
4096     TIME_ZONE_INFORMATION tz;
4097     DWORD tzid = GetTimeZoneInformation(&tz);
4098     int daylightBias =
4099       (tzid == TIME_ZONE_ID_DAYLIGHT) ?  tz.DaylightBias : tz.StandardBias;
4100     sbuf->st_mtime += (tz.Bias + daylightBias) * 60;
4101   }
4102   return ret;
4103 }
4104 
4105 
4106 #define FT2INT64(ft) \
4107   ((jlong)((jlong)(ft).dwHighDateTime << 32 | (julong)(ft).dwLowDateTime))
4108 
4109 
4110 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
4111 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
4112 // of a thread.
4113 //
4114 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
4115 // the fast estimate available on the platform.
4116 
4117 // current_thread_cpu_time() is not optimized for Windows yet
4118 jlong os::current_thread_cpu_time() {
4119   // return user + sys since the cost is the same
4120   return os::thread_cpu_time(Thread::current(), true /* user+sys */);
4121 }
4122 
4123 jlong os::thread_cpu_time(Thread* thread) {
4124   // consistent with what current_thread_cpu_time() returns.
4125   return os::thread_cpu_time(thread, true /* user+sys */);
4126 }
4127 
4128 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
4129   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
4130 }
4131 
4132 jlong os::thread_cpu_time(Thread* thread, bool user_sys_cpu_time) {
4133   // This code is copy from clasic VM -> hpi::sysThreadCPUTime
4134   // If this function changes, os::is_thread_cpu_time_supported() should too
4135   FILETIME CreationTime;
4136   FILETIME ExitTime;
4137   FILETIME KernelTime;
4138   FILETIME UserTime;
4139 
4140   if (GetThreadTimes(thread->osthread()->thread_handle(), &CreationTime,
4141                       &ExitTime, &KernelTime, &UserTime) == 0) {
4142     return -1;
4143   } else if (user_sys_cpu_time) {
4144     return (FT2INT64(UserTime) + FT2INT64(KernelTime)) * 100;
4145   } else {
4146     return FT2INT64(UserTime) * 100;
4147   }
4148 }
4149 
4150 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4151   info_ptr->max_value = ALL_64_BITS;        // the max value -- all 64 bits
4152   info_ptr->may_skip_backward = false;      // GetThreadTimes returns absolute time
4153   info_ptr->may_skip_forward = false;       // GetThreadTimes returns absolute time
4154   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;   // user+system time is returned
4155 }
4156 
4157 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4158   info_ptr->max_value = ALL_64_BITS;        // the max value -- all 64 bits
4159   info_ptr->may_skip_backward = false;      // GetThreadTimes returns absolute time
4160   info_ptr->may_skip_forward = false;       // GetThreadTimes returns absolute time
4161   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;   // user+system time is returned
4162 }
4163 
4164 bool os::is_thread_cpu_time_supported() {
4165   // see os::thread_cpu_time
4166   FILETIME CreationTime;
4167   FILETIME ExitTime;
4168   FILETIME KernelTime;
4169   FILETIME UserTime;
4170 
4171   if (GetThreadTimes(GetCurrentThread(), &CreationTime, &ExitTime,
4172                       &KernelTime, &UserTime) == 0) {
4173     return false;
4174   } else {
4175     return true;
4176   }
4177 }
4178 
4179 // Windows does't provide a loadavg primitive so this is stubbed out for now.
4180 // It does have primitives (PDH API) to get CPU usage and run queue length.
4181 // "\\Processor(_Total)\\% Processor Time", "\\System\\Processor Queue Length"
4182 // If we wanted to implement loadavg on Windows, we have a few options:
4183 //
4184 // a) Query CPU usage and run queue length and "fake" an answer by
4185 //    returning the CPU usage if it's under 100%, and the run queue
4186 //    length otherwise.  It turns out that querying is pretty slow
4187 //    on Windows, on the order of 200 microseconds on a fast machine.
4188 //    Note that on the Windows the CPU usage value is the % usage
4189 //    since the last time the API was called (and the first call
4190 //    returns 100%), so we'd have to deal with that as well.
4191 //
4192 // b) Sample the "fake" answer using a sampling thread and store
4193 //    the answer in a global variable.  The call to loadavg would
4194 //    just return the value of the global, avoiding the slow query.
4195 //
4196 // c) Sample a better answer using exponential decay to smooth the
4197 //    value.  This is basically the algorithm used by UNIX kernels.
4198 //
4199 // Note that sampling thread starvation could affect both (b) and (c).
4200 int os::loadavg(double loadavg[], int nelem) {
4201   return -1;
4202 }
4203 
4204 
4205 // DontYieldALot=false by default: dutifully perform all yields as requested by JVM_Yield()
4206 bool os::dont_yield() {
4207   return DontYieldALot;
4208 }
4209 
4210 // This method is a slightly reworked copy of JDK's sysOpen
4211 // from src/windows/hpi/src/sys_api_md.c
4212 
4213 int os::open(const char *path, int oflag, int mode) {
4214   char pathbuf[MAX_PATH];
4215 
4216   if (strlen(path) > MAX_PATH - 1) {
4217     errno = ENAMETOOLONG;
4218     return -1;
4219   }
4220   os::native_path(strcpy(pathbuf, path));
4221   return ::open(pathbuf, oflag | O_BINARY | O_NOINHERIT, mode);
4222 }
4223 
4224 FILE* os::open(int fd, const char* mode) {
4225   return ::_fdopen(fd, mode);
4226 }
4227 
4228 // Is a (classpath) directory empty?
4229 bool os::dir_is_empty(const char* path) {
4230   WIN32_FIND_DATA fd;
4231   HANDLE f = FindFirstFile(path, &fd);
4232   if (f == INVALID_HANDLE_VALUE) {
4233     return true;
4234   }
4235   FindClose(f);
4236   return false;
4237 }
4238 
4239 // create binary file, rewriting existing file if required
4240 int os::create_binary_file(const char* path, bool rewrite_existing) {
4241   int oflags = _O_CREAT | _O_WRONLY | _O_BINARY;
4242   if (!rewrite_existing) {
4243     oflags |= _O_EXCL;
4244   }
4245   return ::open(path, oflags, _S_IREAD | _S_IWRITE);
4246 }
4247 
4248 // return current position of file pointer
4249 jlong os::current_file_offset(int fd) {
4250   return (jlong)::_lseeki64(fd, (__int64)0L, SEEK_CUR);
4251 }
4252 
4253 // move file pointer to the specified offset
4254 jlong os::seek_to_file_offset(int fd, jlong offset) {
4255   return (jlong)::_lseeki64(fd, (__int64)offset, SEEK_SET);
4256 }
4257 
4258 
4259 jlong os::lseek(int fd, jlong offset, int whence) {
4260   return (jlong) ::_lseeki64(fd, offset, whence);
4261 }
4262 
4263 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
4264   OVERLAPPED ov;
4265   DWORD nread;
4266   BOOL result;
4267 
4268   ZeroMemory(&ov, sizeof(ov));
4269   ov.Offset = (DWORD)offset;
4270   ov.OffsetHigh = (DWORD)(offset >> 32);
4271 
4272   HANDLE h = (HANDLE)::_get_osfhandle(fd);
4273 
4274   result = ReadFile(h, (LPVOID)buf, nBytes, &nread, &ov);
4275 
4276   return result ? nread : 0;
4277 }
4278 
4279 
4280 // This method is a slightly reworked copy of JDK's sysNativePath
4281 // from src/windows/hpi/src/path_md.c
4282 
4283 // Convert a pathname to native format.  On win32, this involves forcing all
4284 // separators to be '\\' rather than '/' (both are legal inputs, but Win95
4285 // sometimes rejects '/') and removing redundant separators.  The input path is
4286 // assumed to have been converted into the character encoding used by the local
4287 // system.  Because this might be a double-byte encoding, care is taken to
4288 // treat double-byte lead characters correctly.
4289 //
4290 // This procedure modifies the given path in place, as the result is never
4291 // longer than the original.  There is no error return; this operation always
4292 // succeeds.
4293 char * os::native_path(char *path) {
4294   char *src = path, *dst = path, *end = path;
4295   char *colon = NULL;  // If a drive specifier is found, this will
4296                        // point to the colon following the drive letter
4297 
4298   // Assumption: '/', '\\', ':', and drive letters are never lead bytes
4299   assert(((!::IsDBCSLeadByte('/')) && (!::IsDBCSLeadByte('\\'))
4300           && (!::IsDBCSLeadByte(':'))), "Illegal lead byte");
4301 
4302   // Check for leading separators
4303 #define isfilesep(c) ((c) == '/' || (c) == '\\')
4304   while (isfilesep(*src)) {
4305     src++;
4306   }
4307 
4308   if (::isalpha(*src) && !::IsDBCSLeadByte(*src) && src[1] == ':') {
4309     // Remove leading separators if followed by drive specifier.  This
4310     // hack is necessary to support file URLs containing drive
4311     // specifiers (e.g., "file://c:/path").  As a side effect,
4312     // "/c:/path" can be used as an alternative to "c:/path".
4313     *dst++ = *src++;
4314     colon = dst;
4315     *dst++ = ':';
4316     src++;
4317   } else {
4318     src = path;
4319     if (isfilesep(src[0]) && isfilesep(src[1])) {
4320       // UNC pathname: Retain first separator; leave src pointed at
4321       // second separator so that further separators will be collapsed
4322       // into the second separator.  The result will be a pathname
4323       // beginning with "\\\\" followed (most likely) by a host name.
4324       src = dst = path + 1;
4325       path[0] = '\\';     // Force first separator to '\\'
4326     }
4327   }
4328 
4329   end = dst;
4330 
4331   // Remove redundant separators from remainder of path, forcing all
4332   // separators to be '\\' rather than '/'. Also, single byte space
4333   // characters are removed from the end of the path because those
4334   // are not legal ending characters on this operating system.
4335   //
4336   while (*src != '\0') {
4337     if (isfilesep(*src)) {
4338       *dst++ = '\\'; src++;
4339       while (isfilesep(*src)) src++;
4340       if (*src == '\0') {
4341         // Check for trailing separator
4342         end = dst;
4343         if (colon == dst - 2) break;  // "z:\\"
4344         if (dst == path + 1) break;   // "\\"
4345         if (dst == path + 2 && isfilesep(path[0])) {
4346           // "\\\\" is not collapsed to "\\" because "\\\\" marks the
4347           // beginning of a UNC pathname.  Even though it is not, by
4348           // itself, a valid UNC pathname, we leave it as is in order
4349           // to be consistent with the path canonicalizer as well
4350           // as the win32 APIs, which treat this case as an invalid
4351           // UNC pathname rather than as an alias for the root
4352           // directory of the current drive.
4353           break;
4354         }
4355         end = --dst;  // Path does not denote a root directory, so
4356                       // remove trailing separator
4357         break;
4358       }
4359       end = dst;
4360     } else {
4361       if (::IsDBCSLeadByte(*src)) {  // Copy a double-byte character
4362         *dst++ = *src++;
4363         if (*src) *dst++ = *src++;
4364         end = dst;
4365       } else {  // Copy a single-byte character
4366         char c = *src++;
4367         *dst++ = c;
4368         // Space is not a legal ending character
4369         if (c != ' ') end = dst;
4370       }
4371     }
4372   }
4373 
4374   *end = '\0';
4375 
4376   // For "z:", add "." to work around a bug in the C runtime library
4377   if (colon == dst - 1) {
4378     path[2] = '.';
4379     path[3] = '\0';
4380   }
4381 
4382   return path;
4383 }
4384 
4385 // This code is a copy of JDK's sysSetLength
4386 // from src/windows/hpi/src/sys_api_md.c
4387 
4388 int os::ftruncate(int fd, jlong length) {
4389   HANDLE h = (HANDLE)::_get_osfhandle(fd);
4390   long high = (long)(length >> 32);
4391   DWORD ret;
4392 
4393   if (h == (HANDLE)(-1)) {
4394     return -1;
4395   }
4396 
4397   ret = ::SetFilePointer(h, (long)(length), &high, FILE_BEGIN);
4398   if ((ret == 0xFFFFFFFF) && (::GetLastError() != NO_ERROR)) {
4399     return -1;
4400   }
4401 
4402   if (::SetEndOfFile(h) == FALSE) {
4403     return -1;
4404   }
4405 
4406   return 0;
4407 }
4408 
4409 int os::get_fileno(FILE* fp) {
4410   return _fileno(fp);
4411 }
4412 
4413 // This code is a copy of JDK's sysSync
4414 // from src/windows/hpi/src/sys_api_md.c
4415 // except for the legacy workaround for a bug in Win 98
4416 
4417 int os::fsync(int fd) {
4418   HANDLE handle = (HANDLE)::_get_osfhandle(fd);
4419 
4420   if ((!::FlushFileBuffers(handle)) &&
4421       (GetLastError() != ERROR_ACCESS_DENIED)) {
4422     // from winerror.h
4423     return -1;
4424   }
4425   return 0;
4426 }
4427 
4428 static int nonSeekAvailable(int, long *);
4429 static int stdinAvailable(int, long *);
4430 
4431 #define S_ISCHR(mode)   (((mode) & _S_IFCHR) == _S_IFCHR)
4432 #define S_ISFIFO(mode)  (((mode) & _S_IFIFO) == _S_IFIFO)
4433 
4434 // This code is a copy of JDK's sysAvailable
4435 // from src/windows/hpi/src/sys_api_md.c
4436 
4437 int os::available(int fd, jlong *bytes) {
4438   jlong cur, end;
4439   struct _stati64 stbuf64;
4440 
4441   if (::_fstati64(fd, &stbuf64) >= 0) {
4442     int mode = stbuf64.st_mode;
4443     if (S_ISCHR(mode) || S_ISFIFO(mode)) {
4444       int ret;
4445       long lpbytes;
4446       if (fd == 0) {
4447         ret = stdinAvailable(fd, &lpbytes);
4448       } else {
4449         ret = nonSeekAvailable(fd, &lpbytes);
4450       }
4451       (*bytes) = (jlong)(lpbytes);
4452       return ret;
4453     }
4454     if ((cur = ::_lseeki64(fd, 0L, SEEK_CUR)) == -1) {
4455       return FALSE;
4456     } else if ((end = ::_lseeki64(fd, 0L, SEEK_END)) == -1) {
4457       return FALSE;
4458     } else if (::_lseeki64(fd, cur, SEEK_SET) == -1) {
4459       return FALSE;
4460     }
4461     *bytes = end - cur;
4462     return TRUE;
4463   } else {
4464     return FALSE;
4465   }
4466 }
4467 
4468 void os::flockfile(FILE* fp) {
4469   _lock_file(fp);
4470 }
4471 
4472 void os::funlockfile(FILE* fp) {
4473   _unlock_file(fp);
4474 }
4475 
4476 // This code is a copy of JDK's nonSeekAvailable
4477 // from src/windows/hpi/src/sys_api_md.c
4478 
4479 static int nonSeekAvailable(int fd, long *pbytes) {
4480   // This is used for available on non-seekable devices
4481   // (like both named and anonymous pipes, such as pipes
4482   //  connected to an exec'd process).
4483   // Standard Input is a special case.
4484   HANDLE han;
4485 
4486   if ((han = (HANDLE) ::_get_osfhandle(fd)) == (HANDLE)(-1)) {
4487     return FALSE;
4488   }
4489 
4490   if (! ::PeekNamedPipe(han, NULL, 0, NULL, (LPDWORD)pbytes, NULL)) {
4491     // PeekNamedPipe fails when at EOF.  In that case we
4492     // simply make *pbytes = 0 which is consistent with the
4493     // behavior we get on Solaris when an fd is at EOF.
4494     // The only alternative is to raise an Exception,
4495     // which isn't really warranted.
4496     //
4497     if (::GetLastError() != ERROR_BROKEN_PIPE) {
4498       return FALSE;
4499     }
4500     *pbytes = 0;
4501   }
4502   return TRUE;
4503 }
4504 
4505 #define MAX_INPUT_EVENTS 2000
4506 
4507 // This code is a copy of JDK's stdinAvailable
4508 // from src/windows/hpi/src/sys_api_md.c
4509 
4510 static int stdinAvailable(int fd, long *pbytes) {
4511   HANDLE han;
4512   DWORD numEventsRead = 0;  // Number of events read from buffer
4513   DWORD numEvents = 0;      // Number of events in buffer
4514   DWORD i = 0;              // Loop index
4515   DWORD curLength = 0;      // Position marker
4516   DWORD actualLength = 0;   // Number of bytes readable
4517   BOOL error = FALSE;       // Error holder
4518   INPUT_RECORD *lpBuffer;   // Pointer to records of input events
4519 
4520   if ((han = ::GetStdHandle(STD_INPUT_HANDLE)) == INVALID_HANDLE_VALUE) {
4521     return FALSE;
4522   }
4523 
4524   // Construct an array of input records in the console buffer
4525   error = ::GetNumberOfConsoleInputEvents(han, &numEvents);
4526   if (error == 0) {
4527     return nonSeekAvailable(fd, pbytes);
4528   }
4529 
4530   // lpBuffer must fit into 64K or else PeekConsoleInput fails
4531   if (numEvents > MAX_INPUT_EVENTS) {
4532     numEvents = MAX_INPUT_EVENTS;
4533   }
4534 
4535   lpBuffer = (INPUT_RECORD *)os::malloc(numEvents * sizeof(INPUT_RECORD), mtInternal);
4536   if (lpBuffer == NULL) {
4537     return FALSE;
4538   }
4539 
4540   error = ::PeekConsoleInput(han, lpBuffer, numEvents, &numEventsRead);
4541   if (error == 0) {
4542     os::free(lpBuffer);
4543     return FALSE;
4544   }
4545 
4546   // Examine input records for the number of bytes available
4547   for (i=0; i<numEvents; i++) {
4548     if (lpBuffer[i].EventType == KEY_EVENT) {
4549 
4550       KEY_EVENT_RECORD *keyRecord = (KEY_EVENT_RECORD *)
4551                                       &(lpBuffer[i].Event);
4552       if (keyRecord->bKeyDown == TRUE) {
4553         CHAR *keyPressed = (CHAR *) &(keyRecord->uChar);
4554         curLength++;
4555         if (*keyPressed == '\r') {
4556           actualLength = curLength;
4557         }
4558       }
4559     }
4560   }
4561 
4562   if (lpBuffer != NULL) {
4563     os::free(lpBuffer);
4564   }
4565 
4566   *pbytes = (long) actualLength;
4567   return TRUE;
4568 }
4569 
4570 // Map a block of memory.
4571 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
4572                         char *addr, size_t bytes, bool read_only,
4573                         bool allow_exec) {
4574   HANDLE hFile;
4575   char* base;
4576 
4577   hFile = CreateFile(file_name, GENERIC_READ, FILE_SHARE_READ, NULL,
4578                      OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
4579   if (hFile == NULL) {
4580     log_info(os)("CreateFile() failed: GetLastError->%ld.", GetLastError());
4581     return NULL;
4582   }
4583 
4584   if (allow_exec) {
4585     // CreateFileMapping/MapViewOfFileEx can't map executable memory
4586     // unless it comes from a PE image (which the shared archive is not.)
4587     // Even VirtualProtect refuses to give execute access to mapped memory
4588     // that was not previously executable.
4589     //
4590     // Instead, stick the executable region in anonymous memory.  Yuck.
4591     // Penalty is that ~4 pages will not be shareable - in the future
4592     // we might consider DLLizing the shared archive with a proper PE
4593     // header so that mapping executable + sharing is possible.
4594 
4595     base = (char*) VirtualAlloc(addr, bytes, MEM_COMMIT | MEM_RESERVE,
4596                                 PAGE_READWRITE);
4597     if (base == NULL) {
4598       log_info(os)("VirtualAlloc() failed: GetLastError->%ld.", GetLastError());
4599       CloseHandle(hFile);
4600       return NULL;
4601     }
4602 
4603     DWORD bytes_read;
4604     OVERLAPPED overlapped;
4605     overlapped.Offset = (DWORD)file_offset;
4606     overlapped.OffsetHigh = 0;
4607     overlapped.hEvent = NULL;
4608     // ReadFile guarantees that if the return value is true, the requested
4609     // number of bytes were read before returning.
4610     bool res = ReadFile(hFile, base, (DWORD)bytes, &bytes_read, &overlapped) != 0;
4611     if (!res) {
4612       log_info(os)("ReadFile() failed: GetLastError->%ld.", GetLastError());
4613       release_memory(base, bytes);
4614       CloseHandle(hFile);
4615       return NULL;
4616     }
4617   } else {
4618     HANDLE hMap = CreateFileMapping(hFile, NULL, PAGE_WRITECOPY, 0, 0,
4619                                     NULL /* file_name */);
4620     if (hMap == NULL) {
4621       log_info(os)("CreateFileMapping() failed: GetLastError->%ld.", GetLastError());
4622       CloseHandle(hFile);
4623       return NULL;
4624     }
4625 
4626     DWORD access = read_only ? FILE_MAP_READ : FILE_MAP_COPY;
4627     base = (char*)MapViewOfFileEx(hMap, access, 0, (DWORD)file_offset,
4628                                   (DWORD)bytes, addr);
4629     if (base == NULL) {
4630       log_info(os)("MapViewOfFileEx() failed: GetLastError->%ld.", GetLastError());
4631       CloseHandle(hMap);
4632       CloseHandle(hFile);
4633       return NULL;
4634     }
4635 
4636     if (CloseHandle(hMap) == 0) {
4637       log_info(os)("CloseHandle(hMap) failed: GetLastError->%ld.", GetLastError());
4638       CloseHandle(hFile);
4639       return base;
4640     }
4641   }
4642 
4643   if (allow_exec) {
4644     DWORD old_protect;
4645     DWORD exec_access = read_only ? PAGE_EXECUTE_READ : PAGE_EXECUTE_READWRITE;
4646     bool res = VirtualProtect(base, bytes, exec_access, &old_protect) != 0;
4647 
4648     if (!res) {
4649       log_info(os)("VirtualProtect() failed: GetLastError->%ld.", GetLastError());
4650       // Don't consider this a hard error, on IA32 even if the
4651       // VirtualProtect fails, we should still be able to execute
4652       CloseHandle(hFile);
4653       return base;
4654     }
4655   }
4656 
4657   if (CloseHandle(hFile) == 0) {
4658     log_info(os)("CloseHandle(hFile) failed: GetLastError->%ld.", GetLastError());
4659     return base;
4660   }
4661 
4662   return base;
4663 }
4664 
4665 
4666 // Remap a block of memory.
4667 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
4668                           char *addr, size_t bytes, bool read_only,
4669                           bool allow_exec) {
4670   // This OS does not allow existing memory maps to be remapped so we
4671   // have to unmap the memory before we remap it.
4672   if (!os::unmap_memory(addr, bytes)) {
4673     return NULL;
4674   }
4675 
4676   // There is a very small theoretical window between the unmap_memory()
4677   // call above and the map_memory() call below where a thread in native
4678   // code may be able to access an address that is no longer mapped.
4679 
4680   return os::map_memory(fd, file_name, file_offset, addr, bytes,
4681                         read_only, allow_exec);
4682 }
4683 
4684 
4685 // Unmap a block of memory.
4686 // Returns true=success, otherwise false.
4687 
4688 bool os::pd_unmap_memory(char* addr, size_t bytes) {
4689   MEMORY_BASIC_INFORMATION mem_info;
4690   if (VirtualQuery(addr, &mem_info, sizeof(mem_info)) == 0) {
4691     log_info(os)("VirtualQuery() failed: GetLastError->%ld.", GetLastError());
4692     return false;
4693   }
4694 
4695   // Executable memory was not mapped using CreateFileMapping/MapViewOfFileEx.
4696   // Instead, executable region was allocated using VirtualAlloc(). See
4697   // pd_map_memory() above.
4698   //
4699   // The following flags should match the 'exec_access' flages used for
4700   // VirtualProtect() in pd_map_memory().
4701   if (mem_info.Protect == PAGE_EXECUTE_READ ||
4702       mem_info.Protect == PAGE_EXECUTE_READWRITE) {
4703     return pd_release_memory(addr, bytes);
4704   }
4705 
4706   BOOL result = UnmapViewOfFile(addr);
4707   if (result == 0) {
4708     log_info(os)("UnmapViewOfFile() failed: GetLastError->%ld.", GetLastError());
4709     return false;
4710   }
4711   return true;
4712 }
4713 
4714 void os::pause() {
4715   char filename[MAX_PATH];
4716   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4717     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4718   } else {
4719     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4720   }
4721 
4722   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4723   if (fd != -1) {
4724     struct stat buf;
4725     ::close(fd);
4726     while (::stat(filename, &buf) == 0) {
4727       Sleep(100);
4728     }
4729   } else {
4730     jio_fprintf(stderr,
4731                 "Could not open pause file '%s', continuing immediately.\n", filename);
4732   }
4733 }
4734 
4735 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
4736 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
4737 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
4738 
4739 os::ThreadCrashProtection::ThreadCrashProtection() {
4740 }
4741 
4742 // See the caveats for this class in os_windows.hpp
4743 // Protects the callback call so that raised OS EXCEPTIONS causes a jump back
4744 // into this method and returns false. If no OS EXCEPTION was raised, returns
4745 // true.
4746 // The callback is supposed to provide the method that should be protected.
4747 //
4748 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
4749 
4750   Thread::muxAcquire(&_crash_mux, "CrashProtection");
4751 
4752   _protected_thread = Thread::current_or_null();
4753   assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
4754 
4755   bool success = true;
4756   __try {
4757     _crash_protection = this;
4758     cb.call();
4759   } __except(EXCEPTION_EXECUTE_HANDLER) {
4760     // only for protection, nothing to do
4761     success = false;
4762   }
4763   _crash_protection = NULL;
4764   _protected_thread = NULL;
4765   Thread::muxRelease(&_crash_mux);
4766   return success;
4767 }
4768 
4769 // An Event wraps a win32 "CreateEvent" kernel handle.
4770 //
4771 // We have a number of choices regarding "CreateEvent" win32 handle leakage:
4772 //
4773 // 1:  When a thread dies return the Event to the EventFreeList, clear the ParkHandle
4774 //     field, and call CloseHandle() on the win32 event handle.  Unpark() would
4775 //     need to be modified to tolerate finding a NULL (invalid) win32 event handle.
4776 //     In addition, an unpark() operation might fetch the handle field, but the
4777 //     event could recycle between the fetch and the SetEvent() operation.
4778 //     SetEvent() would either fail because the handle was invalid, or inadvertently work,
4779 //     as the win32 handle value had been recycled.  In an ideal world calling SetEvent()
4780 //     on an stale but recycled handle would be harmless, but in practice this might
4781 //     confuse other non-Sun code, so it's not a viable approach.
4782 //
4783 // 2:  Once a win32 event handle is associated with an Event, it remains associated
4784 //     with the Event.  The event handle is never closed.  This could be construed
4785 //     as handle leakage, but only up to the maximum # of threads that have been extant
4786 //     at any one time.  This shouldn't be an issue, as windows platforms typically
4787 //     permit a process to have hundreds of thousands of open handles.
4788 //
4789 // 3:  Same as (1), but periodically, at stop-the-world time, rundown the EventFreeList
4790 //     and release unused handles.
4791 //
4792 // 4:  Add a CRITICAL_SECTION to the Event to protect LD+SetEvent from LD;ST(null);CloseHandle.
4793 //     It's not clear, however, that we wouldn't be trading one type of leak for another.
4794 //
4795 // 5.  Use an RCU-like mechanism (Read-Copy Update).
4796 //     Or perhaps something similar to Maged Michael's "Hazard pointers".
4797 //
4798 // We use (2).
4799 //
4800 // TODO-FIXME:
4801 // 1.  Reconcile Doug's JSR166 j.u.c park-unpark with the objectmonitor implementation.
4802 // 2.  Consider wrapping the WaitForSingleObject(Ex) calls in SEH try/finally blocks
4803 //     to recover from (or at least detect) the dreaded Windows 841176 bug.
4804 // 3.  Collapse the interrupt_event, the JSR166 parker event, and the objectmonitor ParkEvent
4805 //     into a single win32 CreateEvent() handle.
4806 //
4807 // Assumption:
4808 //    Only one parker can exist on an event, which is why we allocate
4809 //    them per-thread. Multiple unparkers can coexist.
4810 //
4811 // _Event transitions in park()
4812 //   -1 => -1 : illegal
4813 //    1 =>  0 : pass - return immediately
4814 //    0 => -1 : block; then set _Event to 0 before returning
4815 //
4816 // _Event transitions in unpark()
4817 //    0 => 1 : just return
4818 //    1 => 1 : just return
4819 //   -1 => either 0 or 1; must signal target thread
4820 //         That is, we can safely transition _Event from -1 to either
4821 //         0 or 1.
4822 //
4823 // _Event serves as a restricted-range semaphore.
4824 //   -1 : thread is blocked, i.e. there is a waiter
4825 //    0 : neutral: thread is running or ready,
4826 //        could have been signaled after a wait started
4827 //    1 : signaled - thread is running or ready
4828 //
4829 // Another possible encoding of _Event would be with
4830 // explicit "PARKED" == 01b and "SIGNALED" == 10b bits.
4831 //
4832 
4833 int os::PlatformEvent::park(jlong Millis) {
4834   // Transitions for _Event:
4835   //   -1 => -1 : illegal
4836   //    1 =>  0 : pass - return immediately
4837   //    0 => -1 : block; then set _Event to 0 before returning
4838 
4839   guarantee(_ParkHandle != NULL , "Invariant");
4840   guarantee(Millis > 0          , "Invariant");
4841 
4842   // CONSIDER: defer assigning a CreateEvent() handle to the Event until
4843   // the initial park() operation.
4844   // Consider: use atomic decrement instead of CAS-loop
4845 
4846   int v;
4847   for (;;) {
4848     v = _Event;
4849     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4850   }
4851   guarantee((v == 0) || (v == 1), "invariant");
4852   if (v != 0) return OS_OK;
4853 
4854   // Do this the hard way by blocking ...
4855   // TODO: consider a brief spin here, gated on the success of recent
4856   // spin attempts by this thread.
4857   //
4858   // We decompose long timeouts into series of shorter timed waits.
4859   // Evidently large timo values passed in WaitForSingleObject() are problematic on some
4860   // versions of Windows.  See EventWait() for details.  This may be superstition.  Or not.
4861   // We trust the WAIT_TIMEOUT indication and don't track the elapsed wait time
4862   // with os::javaTimeNanos().  Furthermore, we assume that spurious returns from
4863   // ::WaitForSingleObject() caused by latent ::setEvent() operations will tend
4864   // to happen early in the wait interval.  Specifically, after a spurious wakeup (rv ==
4865   // WAIT_OBJECT_0 but _Event is still < 0) we don't bother to recompute Millis to compensate
4866   // for the already waited time.  This policy does not admit any new outcomes.
4867   // In the future, however, we might want to track the accumulated wait time and
4868   // adjust Millis accordingly if we encounter a spurious wakeup.
4869 
4870   const int MAXTIMEOUT = 0x10000000;
4871   DWORD rv = WAIT_TIMEOUT;
4872   while (_Event < 0 && Millis > 0) {
4873     DWORD prd = Millis;     // set prd = MAX (Millis, MAXTIMEOUT)
4874     if (Millis > MAXTIMEOUT) {
4875       prd = MAXTIMEOUT;
4876     }
4877     rv = ::WaitForSingleObject(_ParkHandle, prd);
4878     assert(rv == WAIT_OBJECT_0 || rv == WAIT_TIMEOUT, "WaitForSingleObject failed");
4879     if (rv == WAIT_TIMEOUT) {
4880       Millis -= prd;
4881     }
4882   }
4883   v = _Event;
4884   _Event = 0;
4885   // see comment at end of os::PlatformEvent::park() below:
4886   OrderAccess::fence();
4887   // If we encounter a nearly simultanous timeout expiry and unpark()
4888   // we return OS_OK indicating we awoke via unpark().
4889   // Implementor's license -- returning OS_TIMEOUT would be equally valid, however.
4890   return (v >= 0) ? OS_OK : OS_TIMEOUT;
4891 }
4892 
4893 void os::PlatformEvent::park() {
4894   // Transitions for _Event:
4895   //   -1 => -1 : illegal
4896   //    1 =>  0 : pass - return immediately
4897   //    0 => -1 : block; then set _Event to 0 before returning
4898 
4899   guarantee(_ParkHandle != NULL, "Invariant");
4900   // Invariant: Only the thread associated with the Event/PlatformEvent
4901   // may call park().
4902   // Consider: use atomic decrement instead of CAS-loop
4903   int v;
4904   for (;;) {
4905     v = _Event;
4906     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4907   }
4908   guarantee((v == 0) || (v == 1), "invariant");
4909   if (v != 0) return;
4910 
4911   // Do this the hard way by blocking ...
4912   // TODO: consider a brief spin here, gated on the success of recent
4913   // spin attempts by this thread.
4914   while (_Event < 0) {
4915     DWORD rv = ::WaitForSingleObject(_ParkHandle, INFINITE);
4916     assert(rv == WAIT_OBJECT_0, "WaitForSingleObject failed");
4917   }
4918 
4919   // Usually we'll find _Event == 0 at this point, but as
4920   // an optional optimization we clear it, just in case can
4921   // multiple unpark() operations drove _Event up to 1.
4922   _Event = 0;
4923   OrderAccess::fence();
4924   guarantee(_Event >= 0, "invariant");
4925 }
4926 
4927 void os::PlatformEvent::unpark() {
4928   guarantee(_ParkHandle != NULL, "Invariant");
4929 
4930   // Transitions for _Event:
4931   //    0 => 1 : just return
4932   //    1 => 1 : just return
4933   //   -1 => either 0 or 1; must signal target thread
4934   //         That is, we can safely transition _Event from -1 to either
4935   //         0 or 1.
4936   // See also: "Semaphores in Plan 9" by Mullender & Cox
4937   //
4938   // Note: Forcing a transition from "-1" to "1" on an unpark() means
4939   // that it will take two back-to-back park() calls for the owning
4940   // thread to block. This has the benefit of forcing a spurious return
4941   // from the first park() call after an unpark() call which will help
4942   // shake out uses of park() and unpark() without condition variables.
4943 
4944   if (Atomic::xchg(1, &_Event) >= 0) return;
4945 
4946   ::SetEvent(_ParkHandle);
4947 }
4948 
4949 
4950 // JSR166
4951 // -------------------------------------------------------
4952 
4953 // The Windows implementation of Park is very straightforward: Basic
4954 // operations on Win32 Events turn out to have the right semantics to
4955 // use them directly. We opportunistically resuse the event inherited
4956 // from Monitor.
4957 
4958 void Parker::park(bool isAbsolute, jlong time) {
4959   guarantee(_ParkEvent != NULL, "invariant");
4960   // First, demultiplex/decode time arguments
4961   if (time < 0) { // don't wait
4962     return;
4963   } else if (time == 0 && !isAbsolute) {
4964     time = INFINITE;
4965   } else if (isAbsolute) {
4966     time -= os::javaTimeMillis(); // convert to relative time
4967     if (time <= 0) {  // already elapsed
4968       return;
4969     }
4970   } else { // relative
4971     time /= 1000000;  // Must coarsen from nanos to millis
4972     if (time == 0) {  // Wait for the minimal time unit if zero
4973       time = 1;
4974     }
4975   }
4976 
4977   JavaThread* thread = JavaThread::current();
4978 
4979   // Don't wait if interrupted or already triggered
4980   if (Thread::is_interrupted(thread, false) ||
4981       WaitForSingleObject(_ParkEvent, 0) == WAIT_OBJECT_0) {
4982     ResetEvent(_ParkEvent);
4983     return;
4984   } else {
4985     ThreadBlockInVM tbivm(thread);
4986     OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4987     thread->set_suspend_equivalent();
4988 
4989     WaitForSingleObject(_ParkEvent, time);
4990     ResetEvent(_ParkEvent);
4991 
4992     // If externally suspended while waiting, re-suspend
4993     if (thread->handle_special_suspend_equivalent_condition()) {
4994       thread->java_suspend_self();
4995     }
4996   }
4997 }
4998 
4999 void Parker::unpark() {
5000   guarantee(_ParkEvent != NULL, "invariant");
5001   SetEvent(_ParkEvent);
5002 }
5003 
5004 // Run the specified command in a separate process. Return its exit value,
5005 // or -1 on failure (e.g. can't create a new process).
5006 int os::fork_and_exec(char* cmd) {
5007   STARTUPINFO si;
5008   PROCESS_INFORMATION pi;
5009   DWORD exit_code;
5010 
5011   char * cmd_string;
5012   char * cmd_prefix = "cmd /C ";
5013   size_t len = strlen(cmd) + strlen(cmd_prefix) + 1;
5014   cmd_string = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtInternal);
5015   if (cmd_string == NULL) {
5016     return -1;
5017   }
5018   cmd_string[0] = '\0';
5019   strcat(cmd_string, cmd_prefix);
5020   strcat(cmd_string, cmd);
5021 
5022   // now replace all '\n' with '&'
5023   char * substring = cmd_string;
5024   while ((substring = strchr(substring, '\n')) != NULL) {
5025     substring[0] = '&';
5026     substring++;
5027   }
5028   memset(&si, 0, sizeof(si));
5029   si.cb = sizeof(si);
5030   memset(&pi, 0, sizeof(pi));
5031   BOOL rslt = CreateProcess(NULL,   // executable name - use command line
5032                             cmd_string,    // command line
5033                             NULL,   // process security attribute
5034                             NULL,   // thread security attribute
5035                             TRUE,   // inherits system handles
5036                             0,      // no creation flags
5037                             NULL,   // use parent's environment block
5038                             NULL,   // use parent's starting directory
5039                             &si,    // (in) startup information
5040                             &pi);   // (out) process information
5041 
5042   if (rslt) {
5043     // Wait until child process exits.
5044     WaitForSingleObject(pi.hProcess, INFINITE);
5045 
5046     GetExitCodeProcess(pi.hProcess, &exit_code);
5047 
5048     // Close process and thread handles.
5049     CloseHandle(pi.hProcess);
5050     CloseHandle(pi.hThread);
5051   } else {
5052     exit_code = -1;
5053   }
5054 
5055   FREE_C_HEAP_ARRAY(char, cmd_string);
5056   return (int)exit_code;
5057 }
5058 
5059 bool os::find(address addr, outputStream* st) {
5060   int offset = -1;
5061   bool result = false;
5062   char buf[256];
5063   if (os::dll_address_to_library_name(addr, buf, sizeof(buf), &offset)) {
5064     st->print(PTR_FORMAT " ", addr);
5065     if (strlen(buf) < sizeof(buf) - 1) {
5066       char* p = strrchr(buf, '\\');
5067       if (p) {
5068         st->print("%s", p + 1);
5069       } else {
5070         st->print("%s", buf);
5071       }
5072     } else {
5073         // The library name is probably truncated. Let's omit the library name.
5074         // See also JDK-8147512.
5075     }
5076     if (os::dll_address_to_function_name(addr, buf, sizeof(buf), &offset)) {
5077       st->print("::%s + 0x%x", buf, offset);
5078     }
5079     st->cr();
5080     result = true;
5081   }
5082   return result;
5083 }
5084 
5085 LONG WINAPI os::win32::serialize_fault_filter(struct _EXCEPTION_POINTERS* e) {
5086   DWORD exception_code = e->ExceptionRecord->ExceptionCode;
5087 
5088   if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
5089     JavaThread* thread = JavaThread::current();
5090     PEXCEPTION_RECORD exceptionRecord = e->ExceptionRecord;
5091     address addr = (address) exceptionRecord->ExceptionInformation[1];
5092 
5093     if (os::is_memory_serialize_page(thread, addr)) {
5094       return EXCEPTION_CONTINUE_EXECUTION;
5095     }
5096   }
5097 
5098   return EXCEPTION_CONTINUE_SEARCH;
5099 }
5100 
5101 // We don't build a headless jre for Windows
5102 bool os::is_headless_jre() { return false; }
5103 
5104 static jint initSock() {
5105   WSADATA wsadata;
5106 
5107   if (WSAStartup(MAKEWORD(2,2), &wsadata) != 0) {
5108     jio_fprintf(stderr, "Could not initialize Winsock (error: %d)\n",
5109                 ::GetLastError());
5110     return JNI_ERR;
5111   }
5112   return JNI_OK;
5113 }
5114 
5115 struct hostent* os::get_host_by_name(char* name) {
5116   return (struct hostent*)gethostbyname(name);
5117 }
5118 
5119 int os::socket_close(int fd) {
5120   return ::closesocket(fd);
5121 }
5122 
5123 int os::socket(int domain, int type, int protocol) {
5124   return ::socket(domain, type, protocol);
5125 }
5126 
5127 int os::connect(int fd, struct sockaddr* him, socklen_t len) {
5128   return ::connect(fd, him, len);
5129 }
5130 
5131 int os::recv(int fd, char* buf, size_t nBytes, uint flags) {
5132   return ::recv(fd, buf, (int)nBytes, flags);
5133 }
5134 
5135 int os::send(int fd, char* buf, size_t nBytes, uint flags) {
5136   return ::send(fd, buf, (int)nBytes, flags);
5137 }
5138 
5139 int os::raw_send(int fd, char* buf, size_t nBytes, uint flags) {
5140   return ::send(fd, buf, (int)nBytes, flags);
5141 }
5142 
5143 // WINDOWS CONTEXT Flags for THREAD_SAMPLING
5144 #if defined(IA32)
5145   #define sampling_context_flags (CONTEXT_FULL | CONTEXT_FLOATING_POINT | CONTEXT_EXTENDED_REGISTERS)
5146 #elif defined (AMD64)
5147   #define sampling_context_flags (CONTEXT_FULL | CONTEXT_FLOATING_POINT)
5148 #endif
5149 
5150 // returns true if thread could be suspended,
5151 // false otherwise
5152 static bool do_suspend(HANDLE* h) {
5153   if (h != NULL) {
5154     if (SuspendThread(*h) != ~0) {
5155       return true;
5156     }
5157   }
5158   return false;
5159 }
5160 
5161 // resume the thread
5162 // calling resume on an active thread is a no-op
5163 static void do_resume(HANDLE* h) {
5164   if (h != NULL) {
5165     ResumeThread(*h);
5166   }
5167 }
5168 
5169 // retrieve a suspend/resume context capable handle
5170 // from the tid. Caller validates handle return value.
5171 void get_thread_handle_for_extended_context(HANDLE* h,
5172                                             OSThread::thread_id_t tid) {
5173   if (h != NULL) {
5174     *h = OpenThread(THREAD_SUSPEND_RESUME | THREAD_GET_CONTEXT | THREAD_QUERY_INFORMATION, FALSE, tid);
5175   }
5176 }
5177 
5178 // Thread sampling implementation
5179 //
5180 void os::SuspendedThreadTask::internal_do_task() {
5181   CONTEXT    ctxt;
5182   HANDLE     h = NULL;
5183 
5184   // get context capable handle for thread
5185   get_thread_handle_for_extended_context(&h, _thread->osthread()->thread_id());
5186 
5187   // sanity
5188   if (h == NULL || h == INVALID_HANDLE_VALUE) {
5189     return;
5190   }
5191 
5192   // suspend the thread
5193   if (do_suspend(&h)) {
5194     ctxt.ContextFlags = sampling_context_flags;
5195     // get thread context
5196     GetThreadContext(h, &ctxt);
5197     SuspendedThreadTaskContext context(_thread, &ctxt);
5198     // pass context to Thread Sampling impl
5199     do_task(context);
5200     // resume thread
5201     do_resume(&h);
5202   }
5203 
5204   // close handle
5205   CloseHandle(h);
5206 }
5207 
5208 bool os::start_debugging(char *buf, int buflen) {
5209   int len = (int)strlen(buf);
5210   char *p = &buf[len];
5211 
5212   jio_snprintf(p, buflen-len,
5213              "\n\n"
5214              "Do you want to debug the problem?\n\n"
5215              "To debug, attach Visual Studio to process %d; then switch to thread 0x%x\n"
5216              "Select 'Yes' to launch Visual Studio automatically (PATH must include msdev)\n"
5217              "Otherwise, select 'No' to abort...",
5218              os::current_process_id(), os::current_thread_id());
5219 
5220   bool yes = os::message_box("Unexpected Error", buf);
5221 
5222   if (yes) {
5223     // os::breakpoint() calls DebugBreak(), which causes a breakpoint
5224     // exception. If VM is running inside a debugger, the debugger will
5225     // catch the exception. Otherwise, the breakpoint exception will reach
5226     // the default windows exception handler, which can spawn a debugger and
5227     // automatically attach to the dying VM.
5228     os::breakpoint();
5229     yes = false;
5230   }
5231   return yes;
5232 }
5233 
5234 void* os::get_default_process_handle() {
5235   return (void*)GetModuleHandle(NULL);
5236 }
5237 
5238 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
5239 // which is used to find statically linked in agents.
5240 // Additionally for windows, takes into account __stdcall names.
5241 // Parameters:
5242 //            sym_name: Symbol in library we are looking for
5243 //            lib_name: Name of library to look in, NULL for shared libs.
5244 //            is_absolute_path == true if lib_name is absolute path to agent
5245 //                                     such as "C:/a/b/L.dll"
5246 //            == false if only the base name of the library is passed in
5247 //               such as "L"
5248 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
5249                                     bool is_absolute_path) {
5250   char *agent_entry_name;
5251   size_t len;
5252   size_t name_len;
5253   size_t prefix_len = strlen(JNI_LIB_PREFIX);
5254   size_t suffix_len = strlen(JNI_LIB_SUFFIX);
5255   const char *start;
5256 
5257   if (lib_name != NULL) {
5258     len = name_len = strlen(lib_name);
5259     if (is_absolute_path) {
5260       // Need to strip path, prefix and suffix
5261       if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
5262         lib_name = ++start;
5263       } else {
5264         // Need to check for drive prefix
5265         if ((start = strchr(lib_name, ':')) != NULL) {
5266           lib_name = ++start;
5267         }
5268       }
5269       if (len <= (prefix_len + suffix_len)) {
5270         return NULL;
5271       }
5272       lib_name += prefix_len;
5273       name_len = strlen(lib_name) - suffix_len;
5274     }
5275   }
5276   len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
5277   agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
5278   if (agent_entry_name == NULL) {
5279     return NULL;
5280   }
5281   if (lib_name != NULL) {
5282     const char *p = strrchr(sym_name, '@');
5283     if (p != NULL && p != sym_name) {
5284       // sym_name == _Agent_OnLoad@XX
5285       strncpy(agent_entry_name, sym_name, (p - sym_name));
5286       agent_entry_name[(p-sym_name)] = '\0';
5287       // agent_entry_name == _Agent_OnLoad
5288       strcat(agent_entry_name, "_");
5289       strncat(agent_entry_name, lib_name, name_len);
5290       strcat(agent_entry_name, p);
5291       // agent_entry_name == _Agent_OnLoad_lib_name@XX
5292     } else {
5293       strcpy(agent_entry_name, sym_name);
5294       strcat(agent_entry_name, "_");
5295       strncat(agent_entry_name, lib_name, name_len);
5296     }
5297   } else {
5298     strcpy(agent_entry_name, sym_name);
5299   }
5300   return agent_entry_name;
5301 }
5302 
5303 #ifndef PRODUCT
5304 
5305 // test the code path in reserve_memory_special() that tries to allocate memory in a single
5306 // contiguous memory block at a particular address.
5307 // The test first tries to find a good approximate address to allocate at by using the same
5308 // method to allocate some memory at any address. The test then tries to allocate memory in
5309 // the vicinity (not directly after it to avoid possible by-chance use of that location)
5310 // This is of course only some dodgy assumption, there is no guarantee that the vicinity of
5311 // the previously allocated memory is available for allocation. The only actual failure
5312 // that is reported is when the test tries to allocate at a particular location but gets a
5313 // different valid one. A NULL return value at this point is not considered an error but may
5314 // be legitimate.
5315 // If -XX:+VerboseInternalVMTests is enabled, print some explanatory messages.
5316 void TestReserveMemorySpecial_test() {
5317   if (!UseLargePages) {
5318     if (VerboseInternalVMTests) {
5319       tty->print("Skipping test because large pages are disabled");
5320     }
5321     return;
5322   }
5323   // save current value of globals
5324   bool old_use_large_pages_individual_allocation = UseLargePagesIndividualAllocation;
5325   bool old_use_numa_interleaving = UseNUMAInterleaving;
5326 
5327   // set globals to make sure we hit the correct code path
5328   UseLargePagesIndividualAllocation = UseNUMAInterleaving = false;
5329 
5330   // do an allocation at an address selected by the OS to get a good one.
5331   const size_t large_allocation_size = os::large_page_size() * 4;
5332   char* result = os::reserve_memory_special(large_allocation_size, os::large_page_size(), NULL, false);
5333   if (result == NULL) {
5334     if (VerboseInternalVMTests) {
5335       tty->print("Failed to allocate control block with size " SIZE_FORMAT ". Skipping remainder of test.",
5336                           large_allocation_size);
5337     }
5338   } else {
5339     os::release_memory_special(result, large_allocation_size);
5340 
5341     // allocate another page within the recently allocated memory area which seems to be a good location. At least
5342     // we managed to get it once.
5343     const size_t expected_allocation_size = os::large_page_size();
5344     char* expected_location = result + os::large_page_size();
5345     char* actual_location = os::reserve_memory_special(expected_allocation_size, os::large_page_size(), expected_location, false);
5346     if (actual_location == NULL) {
5347       if (VerboseInternalVMTests) {
5348         tty->print("Failed to allocate any memory at " PTR_FORMAT " size " SIZE_FORMAT ". Skipping remainder of test.",
5349                             expected_location, large_allocation_size);
5350       }
5351     } else {
5352       // release memory
5353       os::release_memory_special(actual_location, expected_allocation_size);
5354       // only now check, after releasing any memory to avoid any leaks.
5355       assert(actual_location == expected_location,
5356              "Failed to allocate memory at requested location " PTR_FORMAT " of size " SIZE_FORMAT ", is " PTR_FORMAT " instead",
5357              expected_location, expected_allocation_size, actual_location);
5358     }
5359   }
5360 
5361   // restore globals
5362   UseLargePagesIndividualAllocation = old_use_large_pages_individual_allocation;
5363   UseNUMAInterleaving = old_use_numa_interleaving;
5364 }
5365 #endif // PRODUCT
5366 
5367 /*
5368   All the defined signal names for Windows.
5369 
5370   NOTE that not all of these names are accepted by FindSignal!
5371 
5372   For various reasons some of these may be rejected at runtime.
5373 
5374   Here are the names currently accepted by a user of sun.misc.Signal with
5375   1.4.1 (ignoring potential interaction with use of chaining, etc):
5376 
5377      (LIST TBD)
5378 
5379 */
5380 int os::get_signal_number(const char* name) {
5381   static const struct {
5382     char* name;
5383     int   number;
5384   } siglabels [] =
5385     // derived from version 6.0 VC98/include/signal.h
5386   {"ABRT",      SIGABRT,        // abnormal termination triggered by abort cl
5387   "FPE",        SIGFPE,         // floating point exception
5388   "SEGV",       SIGSEGV,        // segment violation
5389   "INT",        SIGINT,         // interrupt
5390   "TERM",       SIGTERM,        // software term signal from kill
5391   "BREAK",      SIGBREAK,       // Ctrl-Break sequence
5392   "ILL",        SIGILL};        // illegal instruction
5393   for (unsigned i = 0; i < ARRAY_SIZE(siglabels); ++i) {
5394     if (strcmp(name, siglabels[i].name) == 0) {
5395       return siglabels[i].number;
5396     }
5397   }
5398   return -1;
5399 }
5400 
5401 // Fast current thread access
5402 
5403 int os::win32::_thread_ptr_offset = 0;
5404 
5405 static void call_wrapper_dummy() {}
5406 
5407 // We need to call the os_exception_wrapper once so that it sets
5408 // up the offset from FS of the thread pointer.
5409 void os::win32::initialize_thread_ptr_offset() {
5410   os::os_exception_wrapper((java_call_t)call_wrapper_dummy,
5411                            NULL, NULL, NULL, NULL);
5412 }