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 "jvm.h"
  30 #include "classfile/classLoader.hpp"
  31 #include "classfile/systemDictionary.hpp"
  32 #include "classfile/vmSymbols.hpp"
  33 #include "code/icBuffer.hpp"
  34 #include "code/vtableStubs.hpp"
  35 #include "compiler/compileBroker.hpp"
  36 #include "compiler/disassembler.hpp"
  37 #include "interpreter/interpreter.hpp"
  38 #include "logging/log.hpp"
  39 #include "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_misc.hpp"
  46 #include "runtime/arguments.hpp"
  47 #include "runtime/atomic.hpp"
  48 #include "runtime/extendedPC.hpp"
  49 #include "runtime/globals.hpp"
  50 #include "runtime/interfaceSupport.hpp"
  51 #include "runtime/java.hpp"
  52 #include "runtime/javaCalls.hpp"
  53 #include "runtime/mutexLocker.hpp"
  54 #include "runtime/objectMonitor.hpp"
  55 #include "runtime/orderAccess.inline.hpp"
  56 #include "runtime/osThread.hpp"
  57 #include "runtime/perfMemory.hpp"
  58 #include "runtime/sharedRuntime.hpp"
  59 #include "runtime/statSampler.hpp"
  60 #include "runtime/stubRoutines.hpp"
  61 #include "runtime/thread.inline.hpp"
  62 #include "runtime/threadCritical.hpp"
  63 #include "runtime/timer.hpp"
  64 #include "runtime/vm_version.hpp"
  65 #include "semaphore_windows.hpp"
  66 #include "services/attachListener.hpp"
  67 #include "services/memTracker.hpp"
  68 #include "services/runtimeService.hpp"
  69 #include "utilities/align.hpp"
  70 #include "utilities/decoder.hpp"
  71 #include "utilities/defaultStream.hpp"
  72 #include "utilities/events.hpp"
  73 #include "utilities/growableArray.hpp"
  74 #include "utilities/macros.hpp"
  75 #include "utilities/vmError.hpp"
  76 #include "symbolengine.hpp"
  77 #include "windbghelp.hpp"
  78 
  79 
  80 #ifdef _DEBUG
  81 #include <crtdbg.h>
  82 #endif
  83 
  84 
  85 #include <windows.h>
  86 #include <sys/types.h>
  87 #include <sys/stat.h>
  88 #include <sys/timeb.h>
  89 #include <objidl.h>
  90 #include <shlobj.h>
  91 
  92 #include <malloc.h>
  93 #include <signal.h>
  94 #include <direct.h>
  95 #include <errno.h>
  96 #include <fcntl.h>
  97 #include <io.h>
  98 #include <process.h>              // For _beginthreadex(), _endthreadex()
  99 #include <imagehlp.h>             // For os::dll_address_to_function_name
 100 // for enumerating dll libraries
 101 #include <vdmdbg.h>
 102 #include <psapi.h>
 103 
 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(&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(&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     // Recalculate pdb search path if a DLL was loaded successfully.
1326     SymbolEngine::recalc_search_path();
1327     return result;
1328   }
1329 
1330   DWORD errcode = GetLastError();
1331   if (errcode == ERROR_MOD_NOT_FOUND) {
1332     strncpy(ebuf, "Can't find dependent libraries", ebuflen - 1);
1333     ebuf[ebuflen - 1] = '\0';
1334     return NULL;
1335   }
1336 
1337   // Parsing dll below
1338   // If we can read dll-info and find that dll was built
1339   // for an architecture other than Hotspot is running in
1340   // - then print to buffer "DLL was built for a different architecture"
1341   // else call os::lasterror to obtain system error message
1342 
1343   // Read system error message into ebuf
1344   // It may or may not be overwritten below (in the for loop and just above)
1345   lasterror(ebuf, (size_t) ebuflen);
1346   ebuf[ebuflen - 1] = '\0';
1347   int fd = ::open(name, O_RDONLY | O_BINARY, 0);
1348   if (fd < 0) {
1349     return NULL;
1350   }
1351 
1352   uint32_t signature_offset;
1353   uint16_t lib_arch = 0;
1354   bool failed_to_get_lib_arch =
1355     ( // Go to position 3c in the dll
1356      (os::seek_to_file_offset(fd, IMAGE_FILE_PTR_TO_SIGNATURE) < 0)
1357      ||
1358      // Read location of signature
1359      (sizeof(signature_offset) !=
1360      (os::read(fd, (void*)&signature_offset, sizeof(signature_offset))))
1361      ||
1362      // Go to COFF File Header in dll
1363      // that is located after "signature" (4 bytes long)
1364      (os::seek_to_file_offset(fd,
1365      signature_offset + IMAGE_FILE_SIGNATURE_LENGTH) < 0)
1366      ||
1367      // Read field that contains code of architecture
1368      // that dll was built for
1369      (sizeof(lib_arch) != (os::read(fd, (void*)&lib_arch, sizeof(lib_arch))))
1370     );
1371 
1372   ::close(fd);
1373   if (failed_to_get_lib_arch) {
1374     // file i/o error - report os::lasterror(...) msg
1375     return NULL;
1376   }
1377 
1378   typedef struct {
1379     uint16_t arch_code;
1380     char* arch_name;
1381   } arch_t;
1382 
1383   static const arch_t arch_array[] = {
1384     {IMAGE_FILE_MACHINE_I386,      (char*)"IA 32"},
1385     {IMAGE_FILE_MACHINE_AMD64,     (char*)"AMD 64"}
1386   };
1387 #if (defined _M_AMD64)
1388   static const uint16_t running_arch = IMAGE_FILE_MACHINE_AMD64;
1389 #elif (defined _M_IX86)
1390   static const uint16_t running_arch = IMAGE_FILE_MACHINE_I386;
1391 #else
1392   #error Method os::dll_load requires that one of following \
1393          is defined :_M_AMD64 or _M_IX86
1394 #endif
1395 
1396 
1397   // Obtain a string for printf operation
1398   // lib_arch_str shall contain string what platform this .dll was built for
1399   // running_arch_str shall string contain what platform Hotspot was built for
1400   char *running_arch_str = NULL, *lib_arch_str = NULL;
1401   for (unsigned int i = 0; i < ARRAY_SIZE(arch_array); i++) {
1402     if (lib_arch == arch_array[i].arch_code) {
1403       lib_arch_str = arch_array[i].arch_name;
1404     }
1405     if (running_arch == arch_array[i].arch_code) {
1406       running_arch_str = arch_array[i].arch_name;
1407     }
1408   }
1409 
1410   assert(running_arch_str,
1411          "Didn't find running architecture code in arch_array");
1412 
1413   // If the architecture is right
1414   // but some other error took place - report os::lasterror(...) msg
1415   if (lib_arch == running_arch) {
1416     return NULL;
1417   }
1418 
1419   if (lib_arch_str != NULL) {
1420     ::_snprintf(ebuf, ebuflen - 1,
1421                 "Can't load %s-bit .dll on a %s-bit platform",
1422                 lib_arch_str, running_arch_str);
1423   } else {
1424     // don't know what architecture this dll was build for
1425     ::_snprintf(ebuf, ebuflen - 1,
1426                 "Can't load this .dll (machine code=0x%x) on a %s-bit platform",
1427                 lib_arch, running_arch_str);
1428   }
1429 
1430   return NULL;
1431 }
1432 
1433 void os::print_dll_info(outputStream *st) {
1434   st->print_cr("Dynamic libraries:");
1435   get_loaded_modules_info(_print_module, (void *)st);
1436 }
1437 
1438 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1439   HANDLE   hProcess;
1440 
1441 # define MAX_NUM_MODULES 128
1442   HMODULE     modules[MAX_NUM_MODULES];
1443   static char filename[MAX_PATH];
1444   int         result = 0;
1445 
1446   int pid = os::current_process_id();
1447   hProcess = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ,
1448                          FALSE, pid);
1449   if (hProcess == NULL) return 0;
1450 
1451   DWORD size_needed;
1452   if (!EnumProcessModules(hProcess, modules, sizeof(modules), &size_needed)) {
1453     CloseHandle(hProcess);
1454     return 0;
1455   }
1456 
1457   // number of modules that are currently loaded
1458   int num_modules = size_needed / sizeof(HMODULE);
1459 
1460   for (int i = 0; i < MIN2(num_modules, MAX_NUM_MODULES); i++) {
1461     // Get Full pathname:
1462     if (!GetModuleFileNameEx(hProcess, modules[i], filename, sizeof(filename))) {
1463       filename[0] = '\0';
1464     }
1465 
1466     MODULEINFO modinfo;
1467     if (!GetModuleInformation(hProcess, modules[i], &modinfo, sizeof(modinfo))) {
1468       modinfo.lpBaseOfDll = NULL;
1469       modinfo.SizeOfImage = 0;
1470     }
1471 
1472     // Invoke callback function
1473     result = callback(filename, (address)modinfo.lpBaseOfDll,
1474                       (address)((u8)modinfo.lpBaseOfDll + (u8)modinfo.SizeOfImage), param);
1475     if (result) break;
1476   }
1477 
1478   CloseHandle(hProcess);
1479   return result;
1480 }
1481 
1482 bool os::get_host_name(char* buf, size_t buflen) {
1483   DWORD size = (DWORD)buflen;
1484   return (GetComputerNameEx(ComputerNameDnsHostname, buf, &size) == TRUE);
1485 }
1486 
1487 void os::get_summary_os_info(char* buf, size_t buflen) {
1488   stringStream sst(buf, buflen);
1489   os::win32::print_windows_version(&sst);
1490   // chop off newline character
1491   char* nl = strchr(buf, '\n');
1492   if (nl != NULL) *nl = '\0';
1493 }
1494 
1495 int os::log_vsnprintf(char* buf, size_t len, const char* fmt, va_list args) {
1496   int ret = vsnprintf(buf, len, fmt, args);
1497   // Get the correct buffer size if buf is too small
1498   if (ret < 0) {
1499     return _vscprintf(fmt, args);
1500   }
1501   return ret;
1502 }
1503 
1504 static inline time_t get_mtime(const char* filename) {
1505   struct stat st;
1506   int ret = os::stat(filename, &st);
1507   assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno));
1508   return st.st_mtime;
1509 }
1510 
1511 int os::compare_file_modified_times(const char* file1, const char* file2) {
1512   time_t t1 = get_mtime(file1);
1513   time_t t2 = get_mtime(file2);
1514   return t1 - t2;
1515 }
1516 
1517 void os::print_os_info_brief(outputStream* st) {
1518   os::print_os_info(st);
1519 }
1520 
1521 void os::print_os_info(outputStream* st) {
1522 #ifdef ASSERT
1523   char buffer[1024];
1524   st->print("HostName: ");
1525   if (get_host_name(buffer, sizeof(buffer))) {
1526     st->print("%s ", buffer);
1527   } else {
1528     st->print("N/A ");
1529   }
1530 #endif
1531   st->print("OS:");
1532   os::win32::print_windows_version(st);
1533 }
1534 
1535 void os::win32::print_windows_version(outputStream* st) {
1536   OSVERSIONINFOEX osvi;
1537   VS_FIXEDFILEINFO *file_info;
1538   TCHAR kernel32_path[MAX_PATH];
1539   UINT len, ret;
1540 
1541   // Use the GetVersionEx information to see if we're on a server or
1542   // workstation edition of Windows. Starting with Windows 8.1 we can't
1543   // trust the OS version information returned by this API.
1544   ZeroMemory(&osvi, sizeof(OSVERSIONINFOEX));
1545   osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
1546   if (!GetVersionEx((OSVERSIONINFO *)&osvi)) {
1547     st->print_cr("Call to GetVersionEx failed");
1548     return;
1549   }
1550   bool is_workstation = (osvi.wProductType == VER_NT_WORKSTATION);
1551 
1552   // Get the full path to \Windows\System32\kernel32.dll and use that for
1553   // determining what version of Windows we're running on.
1554   len = MAX_PATH - (UINT)strlen("\\kernel32.dll") - 1;
1555   ret = GetSystemDirectory(kernel32_path, len);
1556   if (ret == 0 || ret > len) {
1557     st->print_cr("Call to GetSystemDirectory failed");
1558     return;
1559   }
1560   strncat(kernel32_path, "\\kernel32.dll", MAX_PATH - ret);
1561 
1562   DWORD version_size = GetFileVersionInfoSize(kernel32_path, NULL);
1563   if (version_size == 0) {
1564     st->print_cr("Call to GetFileVersionInfoSize failed");
1565     return;
1566   }
1567 
1568   LPTSTR version_info = (LPTSTR)os::malloc(version_size, mtInternal);
1569   if (version_info == NULL) {
1570     st->print_cr("Failed to allocate version_info");
1571     return;
1572   }
1573 
1574   if (!GetFileVersionInfo(kernel32_path, NULL, version_size, version_info)) {
1575     os::free(version_info);
1576     st->print_cr("Call to GetFileVersionInfo failed");
1577     return;
1578   }
1579 
1580   if (!VerQueryValue(version_info, TEXT("\\"), (LPVOID*)&file_info, &len)) {
1581     os::free(version_info);
1582     st->print_cr("Call to VerQueryValue failed");
1583     return;
1584   }
1585 
1586   int major_version = HIWORD(file_info->dwProductVersionMS);
1587   int minor_version = LOWORD(file_info->dwProductVersionMS);
1588   int build_number = HIWORD(file_info->dwProductVersionLS);
1589   int build_minor = LOWORD(file_info->dwProductVersionLS);
1590   int os_vers = major_version * 1000 + minor_version;
1591   os::free(version_info);
1592 
1593   st->print(" Windows ");
1594   switch (os_vers) {
1595 
1596   case 6000:
1597     if (is_workstation) {
1598       st->print("Vista");
1599     } else {
1600       st->print("Server 2008");
1601     }
1602     break;
1603 
1604   case 6001:
1605     if (is_workstation) {
1606       st->print("7");
1607     } else {
1608       st->print("Server 2008 R2");
1609     }
1610     break;
1611 
1612   case 6002:
1613     if (is_workstation) {
1614       st->print("8");
1615     } else {
1616       st->print("Server 2012");
1617     }
1618     break;
1619 
1620   case 6003:
1621     if (is_workstation) {
1622       st->print("8.1");
1623     } else {
1624       st->print("Server 2012 R2");
1625     }
1626     break;
1627 
1628   case 10000:
1629     if (is_workstation) {
1630       st->print("10");
1631     } else {
1632       st->print("Server 2016");
1633     }
1634     break;
1635 
1636   default:
1637     // Unrecognized windows, print out its major and minor versions
1638     st->print("%d.%d", major_version, minor_version);
1639     break;
1640   }
1641 
1642   // Retrieve SYSTEM_INFO from GetNativeSystemInfo call so that we could
1643   // find out whether we are running on 64 bit processor or not
1644   SYSTEM_INFO si;
1645   ZeroMemory(&si, sizeof(SYSTEM_INFO));
1646   GetNativeSystemInfo(&si);
1647   if (si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_AMD64) {
1648     st->print(" , 64 bit");
1649   }
1650 
1651   st->print(" Build %d", build_number);
1652   st->print(" (%d.%d.%d.%d)", major_version, minor_version, build_number, build_minor);
1653   st->cr();
1654 }
1655 
1656 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1657   // Nothing to do for now.
1658 }
1659 
1660 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1661   HKEY key;
1662   DWORD status = RegOpenKey(HKEY_LOCAL_MACHINE,
1663                "HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0", &key);
1664   if (status == ERROR_SUCCESS) {
1665     DWORD size = (DWORD)buflen;
1666     status = RegQueryValueEx(key, "ProcessorNameString", NULL, NULL, (byte*)buf, &size);
1667     if (status != ERROR_SUCCESS) {
1668         strncpy(buf, "## __CPU__", buflen);
1669     }
1670     RegCloseKey(key);
1671   } else {
1672     // Put generic cpu info to return
1673     strncpy(buf, "## __CPU__", buflen);
1674   }
1675 }
1676 
1677 void os::print_memory_info(outputStream* st) {
1678   st->print("Memory:");
1679   st->print(" %dk page", os::vm_page_size()>>10);
1680 
1681   // Use GlobalMemoryStatusEx() because GlobalMemoryStatus() may return incorrect
1682   // value if total memory is larger than 4GB
1683   MEMORYSTATUSEX ms;
1684   ms.dwLength = sizeof(ms);
1685   GlobalMemoryStatusEx(&ms);
1686 
1687   st->print(", physical %uk", os::physical_memory() >> 10);
1688   st->print("(%uk free)", os::available_memory() >> 10);
1689 
1690   st->print(", swap %uk", ms.ullTotalPageFile >> 10);
1691   st->print("(%uk free)", ms.ullAvailPageFile >> 10);
1692   st->cr();
1693 }
1694 
1695 void os::print_siginfo(outputStream *st, const void* siginfo) {
1696   const EXCEPTION_RECORD* const er = (EXCEPTION_RECORD*)siginfo;
1697   st->print("siginfo:");
1698 
1699   char tmp[64];
1700   if (os::exception_name(er->ExceptionCode, tmp, sizeof(tmp)) == NULL) {
1701     strcpy(tmp, "EXCEPTION_??");
1702   }
1703   st->print(" %s (0x%x)", tmp, er->ExceptionCode);
1704 
1705   if ((er->ExceptionCode == EXCEPTION_ACCESS_VIOLATION ||
1706        er->ExceptionCode == EXCEPTION_IN_PAGE_ERROR) &&
1707        er->NumberParameters >= 2) {
1708     switch (er->ExceptionInformation[0]) {
1709     case 0: st->print(", reading address"); break;
1710     case 1: st->print(", writing address"); break;
1711     case 8: st->print(", data execution prevention violation at address"); break;
1712     default: st->print(", ExceptionInformation=" INTPTR_FORMAT,
1713                        er->ExceptionInformation[0]);
1714     }
1715     st->print(" " INTPTR_FORMAT, er->ExceptionInformation[1]);
1716   } else {
1717     int num = er->NumberParameters;
1718     if (num > 0) {
1719       st->print(", ExceptionInformation=");
1720       for (int i = 0; i < num; i++) {
1721         st->print(INTPTR_FORMAT " ", er->ExceptionInformation[i]);
1722       }
1723     }
1724   }
1725   st->cr();
1726 }
1727 
1728 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1729   // do nothing
1730 }
1731 
1732 static char saved_jvm_path[MAX_PATH] = {0};
1733 
1734 // Find the full path to the current module, jvm.dll
1735 void os::jvm_path(char *buf, jint buflen) {
1736   // Error checking.
1737   if (buflen < MAX_PATH) {
1738     assert(false, "must use a large-enough buffer");
1739     buf[0] = '\0';
1740     return;
1741   }
1742   // Lazy resolve the path to current module.
1743   if (saved_jvm_path[0] != 0) {
1744     strcpy(buf, saved_jvm_path);
1745     return;
1746   }
1747 
1748   buf[0] = '\0';
1749   if (Arguments::sun_java_launcher_is_altjvm()) {
1750     // Support for the java launcher's '-XXaltjvm=<path>' option. Check
1751     // for a JAVA_HOME environment variable and fix up the path so it
1752     // looks like jvm.dll is installed there (append a fake suffix
1753     // hotspot/jvm.dll).
1754     char* java_home_var = ::getenv("JAVA_HOME");
1755     if (java_home_var != NULL && java_home_var[0] != 0 &&
1756         strlen(java_home_var) < (size_t)buflen) {
1757       strncpy(buf, java_home_var, buflen);
1758 
1759       // determine if this is a legacy image or modules image
1760       // modules image doesn't have "jre" subdirectory
1761       size_t len = strlen(buf);
1762       char* jrebin_p = buf + len;
1763       jio_snprintf(jrebin_p, buflen-len, "\\jre\\bin\\");
1764       if (0 != _access(buf, 0)) {
1765         jio_snprintf(jrebin_p, buflen-len, "\\bin\\");
1766       }
1767       len = strlen(buf);
1768       jio_snprintf(buf + len, buflen-len, "hotspot\\jvm.dll");
1769     }
1770   }
1771 
1772   if (buf[0] == '\0') {
1773     GetModuleFileName(vm_lib_handle, buf, buflen);
1774   }
1775   strncpy(saved_jvm_path, buf, MAX_PATH);
1776   saved_jvm_path[MAX_PATH - 1] = '\0';
1777 }
1778 
1779 
1780 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1781 #ifndef _WIN64
1782   st->print("_");
1783 #endif
1784 }
1785 
1786 
1787 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1788 #ifndef _WIN64
1789   st->print("@%d", args_size  * sizeof(int));
1790 #endif
1791 }
1792 
1793 // This method is a copy of JDK's sysGetLastErrorString
1794 // from src/windows/hpi/src/system_md.c
1795 
1796 size_t os::lasterror(char* buf, size_t len) {
1797   DWORD errval;
1798 
1799   if ((errval = GetLastError()) != 0) {
1800     // DOS error
1801     size_t n = (size_t)FormatMessage(
1802                                      FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,
1803                                      NULL,
1804                                      errval,
1805                                      0,
1806                                      buf,
1807                                      (DWORD)len,
1808                                      NULL);
1809     if (n > 3) {
1810       // Drop final '.', CR, LF
1811       if (buf[n - 1] == '\n') n--;
1812       if (buf[n - 1] == '\r') n--;
1813       if (buf[n - 1] == '.') n--;
1814       buf[n] = '\0';
1815     }
1816     return n;
1817   }
1818 
1819   if (errno != 0) {
1820     // C runtime error that has no corresponding DOS error code
1821     const char* s = os::strerror(errno);
1822     size_t n = strlen(s);
1823     if (n >= len) n = len - 1;
1824     strncpy(buf, s, n);
1825     buf[n] = '\0';
1826     return n;
1827   }
1828 
1829   return 0;
1830 }
1831 
1832 int os::get_last_error() {
1833   DWORD error = GetLastError();
1834   if (error == 0) {
1835     error = errno;
1836   }
1837   return (int)error;
1838 }
1839 
1840 WindowsSemaphore::WindowsSemaphore(uint value) {
1841   _semaphore = ::CreateSemaphore(NULL, value, LONG_MAX, NULL);
1842 
1843   guarantee(_semaphore != NULL, "CreateSemaphore failed with error code: %lu", GetLastError());
1844 }
1845 
1846 WindowsSemaphore::~WindowsSemaphore() {
1847   ::CloseHandle(_semaphore);
1848 }
1849 
1850 void WindowsSemaphore::signal(uint count) {
1851   if (count > 0) {
1852     BOOL ret = ::ReleaseSemaphore(_semaphore, count, NULL);
1853 
1854     assert(ret != 0, "ReleaseSemaphore failed with error code: %lu", GetLastError());
1855   }
1856 }
1857 
1858 void WindowsSemaphore::wait() {
1859   DWORD ret = ::WaitForSingleObject(_semaphore, INFINITE);
1860   assert(ret != WAIT_FAILED,   "WaitForSingleObject failed with error code: %lu", GetLastError());
1861   assert(ret == WAIT_OBJECT_0, "WaitForSingleObject failed with return value: %lu", ret);
1862 }
1863 
1864 bool WindowsSemaphore::trywait() {
1865   DWORD ret = ::WaitForSingleObject(_semaphore, 0);
1866   assert(ret != WAIT_FAILED,   "WaitForSingleObject failed with error code: %lu", GetLastError());
1867   return ret == WAIT_OBJECT_0;
1868 }
1869 
1870 // sun.misc.Signal
1871 // NOTE that this is a workaround for an apparent kernel bug where if
1872 // a signal handler for SIGBREAK is installed then that signal handler
1873 // takes priority over the console control handler for CTRL_CLOSE_EVENT.
1874 // See bug 4416763.
1875 static void (*sigbreakHandler)(int) = NULL;
1876 
1877 static void UserHandler(int sig, void *siginfo, void *context) {
1878   os::signal_notify(sig);
1879   // We need to reinstate the signal handler each time...
1880   os::signal(sig, (void*)UserHandler);
1881 }
1882 
1883 void* os::user_handler() {
1884   return (void*) UserHandler;
1885 }
1886 
1887 void* os::signal(int signal_number, void* handler) {
1888   if ((signal_number == SIGBREAK) && (!ReduceSignalUsage)) {
1889     void (*oldHandler)(int) = sigbreakHandler;
1890     sigbreakHandler = (void (*)(int)) handler;
1891     return (void*) oldHandler;
1892   } else {
1893     return (void*)::signal(signal_number, (void (*)(int))handler);
1894   }
1895 }
1896 
1897 void os::signal_raise(int signal_number) {
1898   raise(signal_number);
1899 }
1900 
1901 // The Win32 C runtime library maps all console control events other than ^C
1902 // into SIGBREAK, which makes it impossible to distinguish ^BREAK from close,
1903 // logoff, and shutdown events.  We therefore install our own console handler
1904 // that raises SIGTERM for the latter cases.
1905 //
1906 static BOOL WINAPI consoleHandler(DWORD event) {
1907   switch (event) {
1908   case CTRL_C_EVENT:
1909     if (VMError::is_error_reported()) {
1910       // Ctrl-C is pressed during error reporting, likely because the error
1911       // handler fails to abort. Let VM die immediately.
1912       os::die();
1913     }
1914 
1915     os::signal_raise(SIGINT);
1916     return TRUE;
1917     break;
1918   case CTRL_BREAK_EVENT:
1919     if (sigbreakHandler != NULL) {
1920       (*sigbreakHandler)(SIGBREAK);
1921     }
1922     return TRUE;
1923     break;
1924   case CTRL_LOGOFF_EVENT: {
1925     // Don't terminate JVM if it is running in a non-interactive session,
1926     // such as a service process.
1927     USEROBJECTFLAGS flags;
1928     HANDLE handle = GetProcessWindowStation();
1929     if (handle != NULL &&
1930         GetUserObjectInformation(handle, UOI_FLAGS, &flags,
1931         sizeof(USEROBJECTFLAGS), NULL)) {
1932       // If it is a non-interactive session, let next handler to deal
1933       // with it.
1934       if ((flags.dwFlags & WSF_VISIBLE) == 0) {
1935         return FALSE;
1936       }
1937     }
1938   }
1939   case CTRL_CLOSE_EVENT:
1940   case CTRL_SHUTDOWN_EVENT:
1941     os::signal_raise(SIGTERM);
1942     return TRUE;
1943     break;
1944   default:
1945     break;
1946   }
1947   return FALSE;
1948 }
1949 
1950 // The following code is moved from os.cpp for making this
1951 // code platform specific, which it is by its very nature.
1952 
1953 // Return maximum OS signal used + 1 for internal use only
1954 // Used as exit signal for signal_thread
1955 int os::sigexitnum_pd() {
1956   return NSIG;
1957 }
1958 
1959 // a counter for each possible signal value, including signal_thread exit signal
1960 static volatile jint pending_signals[NSIG+1] = { 0 };
1961 static HANDLE sig_sem = NULL;
1962 
1963 void os::signal_init_pd() {
1964   // Initialize signal structures
1965   memset((void*)pending_signals, 0, sizeof(pending_signals));
1966 
1967   sig_sem = ::CreateSemaphore(NULL, 0, NSIG+1, NULL);
1968 
1969   // Programs embedding the VM do not want it to attempt to receive
1970   // events like CTRL_LOGOFF_EVENT, which are used to implement the
1971   // shutdown hooks mechanism introduced in 1.3.  For example, when
1972   // the VM is run as part of a Windows NT service (i.e., a servlet
1973   // engine in a web server), the correct behavior is for any console
1974   // control handler to return FALSE, not TRUE, because the OS's
1975   // "final" handler for such events allows the process to continue if
1976   // it is a service (while terminating it if it is not a service).
1977   // To make this behavior uniform and the mechanism simpler, we
1978   // completely disable the VM's usage of these console events if -Xrs
1979   // (=ReduceSignalUsage) is specified.  This means, for example, that
1980   // the CTRL-BREAK thread dump mechanism is also disabled in this
1981   // case.  See bugs 4323062, 4345157, and related bugs.
1982 
1983   if (!ReduceSignalUsage) {
1984     // Add a CTRL-C handler
1985     SetConsoleCtrlHandler(consoleHandler, TRUE);
1986   }
1987 }
1988 
1989 void os::signal_notify(int signal_number) {
1990   BOOL ret;
1991   if (sig_sem != NULL) {
1992     Atomic::inc(&pending_signals[signal_number]);
1993     ret = ::ReleaseSemaphore(sig_sem, 1, NULL);
1994     assert(ret != 0, "ReleaseSemaphore() failed");
1995   }
1996 }
1997 
1998 static int check_pending_signals(bool wait_for_signal) {
1999   DWORD ret;
2000   while (true) {
2001     for (int i = 0; i < NSIG + 1; i++) {
2002       jint n = pending_signals[i];
2003       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2004         return i;
2005       }
2006     }
2007     if (!wait_for_signal) {
2008       return -1;
2009     }
2010 
2011     JavaThread *thread = JavaThread::current();
2012 
2013     ThreadBlockInVM tbivm(thread);
2014 
2015     bool threadIsSuspended;
2016     do {
2017       thread->set_suspend_equivalent();
2018       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2019       ret = ::WaitForSingleObject(sig_sem, INFINITE);
2020       assert(ret == WAIT_OBJECT_0, "WaitForSingleObject() failed");
2021 
2022       // were we externally suspended while we were waiting?
2023       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2024       if (threadIsSuspended) {
2025         // The semaphore has been incremented, but while we were waiting
2026         // another thread suspended us. We don't want to continue running
2027         // while suspended because that would surprise the thread that
2028         // suspended us.
2029         ret = ::ReleaseSemaphore(sig_sem, 1, NULL);
2030         assert(ret != 0, "ReleaseSemaphore() failed");
2031 
2032         thread->java_suspend_self();
2033       }
2034     } while (threadIsSuspended);
2035   }
2036 }
2037 
2038 int os::signal_lookup() {
2039   return check_pending_signals(false);
2040 }
2041 
2042 int os::signal_wait() {
2043   return check_pending_signals(true);
2044 }
2045 
2046 // Implicit OS exception handling
2047 
2048 LONG Handle_Exception(struct _EXCEPTION_POINTERS* exceptionInfo,
2049                       address handler) {
2050   JavaThread* thread = (JavaThread*) Thread::current_or_null();
2051   // Save pc in thread
2052 #ifdef _M_AMD64
2053   // Do not blow up if no thread info available.
2054   if (thread) {
2055     thread->set_saved_exception_pc((address)(DWORD_PTR)exceptionInfo->ContextRecord->Rip);
2056   }
2057   // Set pc to handler
2058   exceptionInfo->ContextRecord->Rip = (DWORD64)handler;
2059 #else
2060   // Do not blow up if no thread info available.
2061   if (thread) {
2062     thread->set_saved_exception_pc((address)(DWORD_PTR)exceptionInfo->ContextRecord->Eip);
2063   }
2064   // Set pc to handler
2065   exceptionInfo->ContextRecord->Eip = (DWORD)(DWORD_PTR)handler;
2066 #endif
2067 
2068   // Continue the execution
2069   return EXCEPTION_CONTINUE_EXECUTION;
2070 }
2071 
2072 
2073 // Used for PostMortemDump
2074 extern "C" void safepoints();
2075 extern "C" void find(int x);
2076 extern "C" void events();
2077 
2078 // According to Windows API documentation, an illegal instruction sequence should generate
2079 // the 0xC000001C exception code. However, real world experience shows that occasionnaly
2080 // the execution of an illegal instruction can generate the exception code 0xC000001E. This
2081 // seems to be an undocumented feature of Win NT 4.0 (and probably other Windows systems).
2082 
2083 #define EXCEPTION_ILLEGAL_INSTRUCTION_2 0xC000001E
2084 
2085 // From "Execution Protection in the Windows Operating System" draft 0.35
2086 // Once a system header becomes available, the "real" define should be
2087 // included or copied here.
2088 #define EXCEPTION_INFO_EXEC_VIOLATION 0x08
2089 
2090 // Windows Vista/2008 heap corruption check
2091 #define EXCEPTION_HEAP_CORRUPTION        0xC0000374
2092 
2093 // All Visual C++ exceptions thrown from code generated by the Microsoft Visual
2094 // C++ compiler contain this error code. Because this is a compiler-generated
2095 // error, the code is not listed in the Win32 API header files.
2096 // The code is actually a cryptic mnemonic device, with the initial "E"
2097 // standing for "exception" and the final 3 bytes (0x6D7363) representing the
2098 // ASCII values of "msc".
2099 
2100 #define EXCEPTION_UNCAUGHT_CXX_EXCEPTION    0xE06D7363
2101 
2102 #define def_excpt(val) { #val, (val) }
2103 
2104 static const struct { char* name; uint number; } exceptlabels[] = {
2105     def_excpt(EXCEPTION_ACCESS_VIOLATION),
2106     def_excpt(EXCEPTION_DATATYPE_MISALIGNMENT),
2107     def_excpt(EXCEPTION_BREAKPOINT),
2108     def_excpt(EXCEPTION_SINGLE_STEP),
2109     def_excpt(EXCEPTION_ARRAY_BOUNDS_EXCEEDED),
2110     def_excpt(EXCEPTION_FLT_DENORMAL_OPERAND),
2111     def_excpt(EXCEPTION_FLT_DIVIDE_BY_ZERO),
2112     def_excpt(EXCEPTION_FLT_INEXACT_RESULT),
2113     def_excpt(EXCEPTION_FLT_INVALID_OPERATION),
2114     def_excpt(EXCEPTION_FLT_OVERFLOW),
2115     def_excpt(EXCEPTION_FLT_STACK_CHECK),
2116     def_excpt(EXCEPTION_FLT_UNDERFLOW),
2117     def_excpt(EXCEPTION_INT_DIVIDE_BY_ZERO),
2118     def_excpt(EXCEPTION_INT_OVERFLOW),
2119     def_excpt(EXCEPTION_PRIV_INSTRUCTION),
2120     def_excpt(EXCEPTION_IN_PAGE_ERROR),
2121     def_excpt(EXCEPTION_ILLEGAL_INSTRUCTION),
2122     def_excpt(EXCEPTION_ILLEGAL_INSTRUCTION_2),
2123     def_excpt(EXCEPTION_NONCONTINUABLE_EXCEPTION),
2124     def_excpt(EXCEPTION_STACK_OVERFLOW),
2125     def_excpt(EXCEPTION_INVALID_DISPOSITION),
2126     def_excpt(EXCEPTION_GUARD_PAGE),
2127     def_excpt(EXCEPTION_INVALID_HANDLE),
2128     def_excpt(EXCEPTION_UNCAUGHT_CXX_EXCEPTION),
2129     def_excpt(EXCEPTION_HEAP_CORRUPTION)
2130 };
2131 
2132 #undef def_excpt
2133 
2134 const char* os::exception_name(int exception_code, char *buf, size_t size) {
2135   uint code = static_cast<uint>(exception_code);
2136   for (uint i = 0; i < ARRAY_SIZE(exceptlabels); ++i) {
2137     if (exceptlabels[i].number == code) {
2138       jio_snprintf(buf, size, "%s", exceptlabels[i].name);
2139       return buf;
2140     }
2141   }
2142 
2143   return NULL;
2144 }
2145 
2146 //-----------------------------------------------------------------------------
2147 LONG Handle_IDiv_Exception(struct _EXCEPTION_POINTERS* exceptionInfo) {
2148   // handle exception caused by idiv; should only happen for -MinInt/-1
2149   // (division by zero is handled explicitly)
2150 #ifdef  _M_AMD64
2151   PCONTEXT ctx = exceptionInfo->ContextRecord;
2152   address pc = (address)ctx->Rip;
2153   assert(pc[0] >= Assembler::REX && pc[0] <= Assembler::REX_WRXB && pc[1] == 0xF7 || pc[0] == 0xF7, "not an idiv opcode");
2154   assert(pc[0] >= Assembler::REX && pc[0] <= Assembler::REX_WRXB && (pc[2] & ~0x7) == 0xF8 || (pc[1] & ~0x7) == 0xF8, "cannot handle non-register operands");
2155   if (pc[0] == 0xF7) {
2156     // set correct result values and continue after idiv instruction
2157     ctx->Rip = (DWORD64)pc + 2;        // idiv reg, reg  is 2 bytes
2158   } else {
2159     ctx->Rip = (DWORD64)pc + 3;        // REX idiv reg, reg  is 3 bytes
2160   }
2161   // Do not set ctx->Rax as it already contains the correct value (either 32 or 64 bit, depending on the operation)
2162   // this is the case because the exception only happens for -MinValue/-1 and -MinValue is always in rax because of the
2163   // idiv opcode (0xF7).
2164   ctx->Rdx = (DWORD)0;             // remainder
2165   // Continue the execution
2166 #else
2167   PCONTEXT ctx = exceptionInfo->ContextRecord;
2168   address pc = (address)ctx->Eip;
2169   assert(pc[0] == 0xF7, "not an idiv opcode");
2170   assert((pc[1] & ~0x7) == 0xF8, "cannot handle non-register operands");
2171   assert(ctx->Eax == min_jint, "unexpected idiv exception");
2172   // set correct result values and continue after idiv instruction
2173   ctx->Eip = (DWORD)pc + 2;        // idiv reg, reg  is 2 bytes
2174   ctx->Eax = (DWORD)min_jint;      // result
2175   ctx->Edx = (DWORD)0;             // remainder
2176   // Continue the execution
2177 #endif
2178   return EXCEPTION_CONTINUE_EXECUTION;
2179 }
2180 
2181 //-----------------------------------------------------------------------------
2182 LONG WINAPI Handle_FLT_Exception(struct _EXCEPTION_POINTERS* exceptionInfo) {
2183   PCONTEXT ctx = exceptionInfo->ContextRecord;
2184 #ifndef  _WIN64
2185   // handle exception caused by native method modifying control word
2186   DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode;
2187 
2188   switch (exception_code) {
2189   case EXCEPTION_FLT_DENORMAL_OPERAND:
2190   case EXCEPTION_FLT_DIVIDE_BY_ZERO:
2191   case EXCEPTION_FLT_INEXACT_RESULT:
2192   case EXCEPTION_FLT_INVALID_OPERATION:
2193   case EXCEPTION_FLT_OVERFLOW:
2194   case EXCEPTION_FLT_STACK_CHECK:
2195   case EXCEPTION_FLT_UNDERFLOW:
2196     jint fp_control_word = (* (jint*) StubRoutines::addr_fpu_cntrl_wrd_std());
2197     if (fp_control_word != ctx->FloatSave.ControlWord) {
2198       // Restore FPCW and mask out FLT exceptions
2199       ctx->FloatSave.ControlWord = fp_control_word | 0xffffffc0;
2200       // Mask out pending FLT exceptions
2201       ctx->FloatSave.StatusWord &=  0xffffff00;
2202       return EXCEPTION_CONTINUE_EXECUTION;
2203     }
2204   }
2205 
2206   if (prev_uef_handler != NULL) {
2207     // We didn't handle this exception so pass it to the previous
2208     // UnhandledExceptionFilter.
2209     return (prev_uef_handler)(exceptionInfo);
2210   }
2211 #else // !_WIN64
2212   // On Windows, the mxcsr control bits are non-volatile across calls
2213   // See also CR 6192333
2214   //
2215   jint MxCsr = INITIAL_MXCSR;
2216   // we can't use StubRoutines::addr_mxcsr_std()
2217   // because in Win64 mxcsr is not saved there
2218   if (MxCsr != ctx->MxCsr) {
2219     ctx->MxCsr = MxCsr;
2220     return EXCEPTION_CONTINUE_EXECUTION;
2221   }
2222 #endif // !_WIN64
2223 
2224   return EXCEPTION_CONTINUE_SEARCH;
2225 }
2226 
2227 static inline void report_error(Thread* t, DWORD exception_code,
2228                                 address addr, void* siginfo, void* context) {
2229   VMError::report_and_die(t, exception_code, addr, siginfo, context);
2230 
2231   // If UseOsErrorReporting, this will return here and save the error file
2232   // somewhere where we can find it in the minidump.
2233 }
2234 
2235 bool os::win32::get_frame_at_stack_banging_point(JavaThread* thread,
2236         struct _EXCEPTION_POINTERS* exceptionInfo, address pc, frame* fr) {
2237   PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2238   address addr = (address) exceptionRecord->ExceptionInformation[1];
2239   if (Interpreter::contains(pc)) {
2240     *fr = os::fetch_frame_from_context((void*)exceptionInfo->ContextRecord);
2241     if (!fr->is_first_java_frame()) {
2242       // get_frame_at_stack_banging_point() is only called when we
2243       // have well defined stacks so java_sender() calls do not need
2244       // to assert safe_for_sender() first.
2245       *fr = fr->java_sender();
2246     }
2247   } else {
2248     // more complex code with compiled code
2249     assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
2250     CodeBlob* cb = CodeCache::find_blob(pc);
2251     if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
2252       // Not sure where the pc points to, fallback to default
2253       // stack overflow handling
2254       return false;
2255     } else {
2256       *fr = os::fetch_frame_from_context((void*)exceptionInfo->ContextRecord);
2257       // in compiled code, the stack banging is performed just after the return pc
2258       // has been pushed on the stack
2259       *fr = frame(fr->sp() + 1, fr->fp(), (address)*(fr->sp()));
2260       if (!fr->is_java_frame()) {
2261         // See java_sender() comment above.
2262         *fr = fr->java_sender();
2263       }
2264     }
2265   }
2266   assert(fr->is_java_frame(), "Safety check");
2267   return true;
2268 }
2269 
2270 //-----------------------------------------------------------------------------
2271 LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
2272   if (InterceptOSException) return EXCEPTION_CONTINUE_SEARCH;
2273   DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode;
2274 #ifdef _M_AMD64
2275   address pc = (address) exceptionInfo->ContextRecord->Rip;
2276 #else
2277   address pc = (address) exceptionInfo->ContextRecord->Eip;
2278 #endif
2279   Thread* t = Thread::current_or_null_safe();
2280 
2281   // Handle SafeFetch32 and SafeFetchN exceptions.
2282   if (StubRoutines::is_safefetch_fault(pc)) {
2283     return Handle_Exception(exceptionInfo, StubRoutines::continuation_for_safefetch_fault(pc));
2284   }
2285 
2286 #ifndef _WIN64
2287   // Execution protection violation - win32 running on AMD64 only
2288   // Handled first to avoid misdiagnosis as a "normal" access violation;
2289   // This is safe to do because we have a new/unique ExceptionInformation
2290   // code for this condition.
2291   if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2292     PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2293     int exception_subcode = (int) exceptionRecord->ExceptionInformation[0];
2294     address addr = (address) exceptionRecord->ExceptionInformation[1];
2295 
2296     if (exception_subcode == EXCEPTION_INFO_EXEC_VIOLATION) {
2297       int page_size = os::vm_page_size();
2298 
2299       // Make sure the pc and the faulting address are sane.
2300       //
2301       // If an instruction spans a page boundary, and the page containing
2302       // the beginning of the instruction is executable but the following
2303       // page is not, the pc and the faulting address might be slightly
2304       // different - we still want to unguard the 2nd page in this case.
2305       //
2306       // 15 bytes seems to be a (very) safe value for max instruction size.
2307       bool pc_is_near_addr =
2308         (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
2309       bool instr_spans_page_boundary =
2310         (align_down((intptr_t) pc ^ (intptr_t) addr,
2311                          (intptr_t) page_size) > 0);
2312 
2313       if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
2314         static volatile address last_addr =
2315           (address) os::non_memory_address_word();
2316 
2317         // In conservative mode, don't unguard unless the address is in the VM
2318         if (UnguardOnExecutionViolation > 0 && addr != last_addr &&
2319             (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
2320 
2321           // Set memory to RWX and retry
2322           address page_start = align_down(addr, page_size);
2323           bool res = os::protect_memory((char*) page_start, page_size,
2324                                         os::MEM_PROT_RWX);
2325 
2326           log_debug(os)("Execution protection violation "
2327                         "at " INTPTR_FORMAT
2328                         ", unguarding " INTPTR_FORMAT ": %s", p2i(addr),
2329                         p2i(page_start), (res ? "success" : os::strerror(errno)));
2330 
2331           // Set last_addr so if we fault again at the same address, we don't
2332           // end up in an endless loop.
2333           //
2334           // There are two potential complications here.  Two threads trapping
2335           // at the same address at the same time could cause one of the
2336           // threads to think it already unguarded, and abort the VM.  Likely
2337           // very rare.
2338           //
2339           // The other race involves two threads alternately trapping at
2340           // different addresses and failing to unguard the page, resulting in
2341           // an endless loop.  This condition is probably even more unlikely
2342           // than the first.
2343           //
2344           // Although both cases could be avoided by using locks or thread
2345           // local last_addr, these solutions are unnecessary complication:
2346           // this handler is a best-effort safety net, not a complete solution.
2347           // It is disabled by default and should only be used as a workaround
2348           // in case we missed any no-execute-unsafe VM code.
2349 
2350           last_addr = addr;
2351 
2352           return EXCEPTION_CONTINUE_EXECUTION;
2353         }
2354       }
2355 
2356       // Last unguard failed or not unguarding
2357       tty->print_raw_cr("Execution protection violation");
2358       report_error(t, exception_code, addr, exceptionInfo->ExceptionRecord,
2359                    exceptionInfo->ContextRecord);
2360       return EXCEPTION_CONTINUE_SEARCH;
2361     }
2362   }
2363 #endif // _WIN64
2364 
2365   // Check to see if we caught the safepoint code in the
2366   // process of write protecting the memory serialization page.
2367   // It write enables the page immediately after protecting it
2368   // so just return.
2369   if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2370     if (t != NULL && t->is_Java_thread()) {
2371       JavaThread* thread = (JavaThread*) t;
2372       PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2373       address addr = (address) exceptionRecord->ExceptionInformation[1];
2374       if (os::is_memory_serialize_page(thread, addr)) {
2375         // Block current thread until the memory serialize page permission restored.
2376         os::block_on_serialize_page_trap();
2377         return EXCEPTION_CONTINUE_EXECUTION;
2378       }
2379     }
2380   }
2381 
2382   if ((exception_code == EXCEPTION_ACCESS_VIOLATION) &&
2383       VM_Version::is_cpuinfo_segv_addr(pc)) {
2384     // Verify that OS save/restore AVX registers.
2385     return Handle_Exception(exceptionInfo, VM_Version::cpuinfo_cont_addr());
2386   }
2387 
2388   if (t != NULL && t->is_Java_thread()) {
2389     JavaThread* thread = (JavaThread*) t;
2390     bool in_java = thread->thread_state() == _thread_in_Java;
2391 
2392     // Handle potential stack overflows up front.
2393     if (exception_code == EXCEPTION_STACK_OVERFLOW) {
2394       if (thread->stack_guards_enabled()) {
2395         if (in_java) {
2396           frame fr;
2397           PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2398           address addr = (address) exceptionRecord->ExceptionInformation[1];
2399           if (os::win32::get_frame_at_stack_banging_point(thread, exceptionInfo, pc, &fr)) {
2400             assert(fr.is_java_frame(), "Must be a Java frame");
2401             SharedRuntime::look_for_reserved_stack_annotated_method(thread, fr);
2402           }
2403         }
2404         // Yellow zone violation.  The o/s has unprotected the first yellow
2405         // zone page for us.  Note:  must call disable_stack_yellow_zone to
2406         // update the enabled status, even if the zone contains only one page.
2407         assert(thread->thread_state() != _thread_in_vm, "Undersized StackShadowPages");
2408         thread->disable_stack_yellow_reserved_zone();
2409         // If not in java code, return and hope for the best.
2410         return in_java
2411             ? Handle_Exception(exceptionInfo, SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW))
2412             :  EXCEPTION_CONTINUE_EXECUTION;
2413       } else {
2414         // Fatal red zone violation.
2415         thread->disable_stack_red_zone();
2416         tty->print_raw_cr("An unrecoverable stack overflow has occurred.");
2417         report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
2418                       exceptionInfo->ContextRecord);
2419         return EXCEPTION_CONTINUE_SEARCH;
2420       }
2421     } else if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2422       // Either stack overflow or null pointer exception.
2423       if (in_java) {
2424         PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2425         address addr = (address) exceptionRecord->ExceptionInformation[1];
2426         address stack_end = thread->stack_end();
2427         if (addr < stack_end && addr >= stack_end - os::vm_page_size()) {
2428           // Stack overflow.
2429           assert(!os::uses_stack_guard_pages(),
2430                  "should be caught by red zone code above.");
2431           return Handle_Exception(exceptionInfo,
2432                                   SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::STACK_OVERFLOW));
2433         }
2434         // Check for safepoint polling and implicit null
2435         // We only expect null pointers in the stubs (vtable)
2436         // the rest are checked explicitly now.
2437         CodeBlob* cb = CodeCache::find_blob(pc);
2438         if (cb != NULL) {
2439           if (os::is_poll_address(addr)) {
2440             address stub = SharedRuntime::get_poll_stub(pc);
2441             return Handle_Exception(exceptionInfo, stub);
2442           }
2443         }
2444         {
2445 #ifdef _WIN64
2446           // If it's a legal stack address map the entire region in
2447           //
2448           PEXCEPTION_RECORD exceptionRecord = exceptionInfo->ExceptionRecord;
2449           address addr = (address) exceptionRecord->ExceptionInformation[1];
2450           if (addr > thread->stack_reserved_zone_base() && addr < thread->stack_base()) {
2451             addr = (address)((uintptr_t)addr &
2452                              (~((uintptr_t)os::vm_page_size() - (uintptr_t)1)));
2453             os::commit_memory((char *)addr, thread->stack_base() - addr,
2454                               !ExecMem);
2455             return EXCEPTION_CONTINUE_EXECUTION;
2456           } else
2457 #endif
2458           {
2459             // Null pointer exception.
2460             if (!MacroAssembler::needs_explicit_null_check((intptr_t)addr)) {
2461               address stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
2462               if (stub != NULL) return Handle_Exception(exceptionInfo, stub);
2463             }
2464             report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
2465                          exceptionInfo->ContextRecord);
2466             return EXCEPTION_CONTINUE_SEARCH;
2467           }
2468         }
2469       }
2470 
2471 #ifdef _WIN64
2472       // Special care for fast JNI field accessors.
2473       // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks
2474       // in and the heap gets shrunk before the field access.
2475       if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2476         address addr = JNI_FastGetField::find_slowcase_pc(pc);
2477         if (addr != (address)-1) {
2478           return Handle_Exception(exceptionInfo, addr);
2479         }
2480       }
2481 #endif
2482 
2483       // Stack overflow or null pointer exception in native code.
2484       report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
2485                    exceptionInfo->ContextRecord);
2486       return EXCEPTION_CONTINUE_SEARCH;
2487     } // /EXCEPTION_ACCESS_VIOLATION
2488     // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
2489 
2490     if (in_java) {
2491       switch (exception_code) {
2492       case EXCEPTION_INT_DIVIDE_BY_ZERO:
2493         return Handle_Exception(exceptionInfo, SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_DIVIDE_BY_ZERO));
2494 
2495       case EXCEPTION_INT_OVERFLOW:
2496         return Handle_IDiv_Exception(exceptionInfo);
2497 
2498       } // switch
2499     }
2500     if (((thread->thread_state() == _thread_in_Java) ||
2501          (thread->thread_state() == _thread_in_native)) &&
2502          exception_code != EXCEPTION_UNCAUGHT_CXX_EXCEPTION) {
2503       LONG result=Handle_FLT_Exception(exceptionInfo);
2504       if (result==EXCEPTION_CONTINUE_EXECUTION) return result;
2505     }
2506   }
2507 
2508   if (exception_code != EXCEPTION_BREAKPOINT) {
2509     report_error(t, exception_code, pc, exceptionInfo->ExceptionRecord,
2510                  exceptionInfo->ContextRecord);
2511   }
2512   return EXCEPTION_CONTINUE_SEARCH;
2513 }
2514 
2515 #ifndef _WIN64
2516 // Special care for fast JNI accessors.
2517 // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in and
2518 // the heap gets shrunk before the field access.
2519 // Need to install our own structured exception handler since native code may
2520 // install its own.
2521 LONG WINAPI fastJNIAccessorExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
2522   DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode;
2523   if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
2524     address pc = (address) exceptionInfo->ContextRecord->Eip;
2525     address addr = JNI_FastGetField::find_slowcase_pc(pc);
2526     if (addr != (address)-1) {
2527       return Handle_Exception(exceptionInfo, addr);
2528     }
2529   }
2530   return EXCEPTION_CONTINUE_SEARCH;
2531 }
2532 
2533 #define DEFINE_FAST_GETFIELD(Return, Fieldname, Result)                     \
2534   Return JNICALL jni_fast_Get##Result##Field_wrapper(JNIEnv *env,           \
2535                                                      jobject obj,           \
2536                                                      jfieldID fieldID) {    \
2537     __try {                                                                 \
2538       return (*JNI_FastGetField::jni_fast_Get##Result##Field_fp)(env,       \
2539                                                                  obj,       \
2540                                                                  fieldID);  \
2541     } __except(fastJNIAccessorExceptionFilter((_EXCEPTION_POINTERS*)        \
2542                                               _exception_info())) {         \
2543     }                                                                       \
2544     return 0;                                                               \
2545   }
2546 
2547 DEFINE_FAST_GETFIELD(jboolean, bool,   Boolean)
2548 DEFINE_FAST_GETFIELD(jbyte,    byte,   Byte)
2549 DEFINE_FAST_GETFIELD(jchar,    char,   Char)
2550 DEFINE_FAST_GETFIELD(jshort,   short,  Short)
2551 DEFINE_FAST_GETFIELD(jint,     int,    Int)
2552 DEFINE_FAST_GETFIELD(jlong,    long,   Long)
2553 DEFINE_FAST_GETFIELD(jfloat,   float,  Float)
2554 DEFINE_FAST_GETFIELD(jdouble,  double, Double)
2555 
2556 address os::win32::fast_jni_accessor_wrapper(BasicType type) {
2557   switch (type) {
2558   case T_BOOLEAN: return (address)jni_fast_GetBooleanField_wrapper;
2559   case T_BYTE:    return (address)jni_fast_GetByteField_wrapper;
2560   case T_CHAR:    return (address)jni_fast_GetCharField_wrapper;
2561   case T_SHORT:   return (address)jni_fast_GetShortField_wrapper;
2562   case T_INT:     return (address)jni_fast_GetIntField_wrapper;
2563   case T_LONG:    return (address)jni_fast_GetLongField_wrapper;
2564   case T_FLOAT:   return (address)jni_fast_GetFloatField_wrapper;
2565   case T_DOUBLE:  return (address)jni_fast_GetDoubleField_wrapper;
2566   default:        ShouldNotReachHere();
2567   }
2568   return (address)-1;
2569 }
2570 #endif
2571 
2572 // Virtual Memory
2573 
2574 int os::vm_page_size() { return os::win32::vm_page_size(); }
2575 int os::vm_allocation_granularity() {
2576   return os::win32::vm_allocation_granularity();
2577 }
2578 
2579 // Windows large page support is available on Windows 2003. In order to use
2580 // large page memory, the administrator must first assign additional privilege
2581 // to the user:
2582 //   + select Control Panel -> Administrative Tools -> Local Security Policy
2583 //   + select Local Policies -> User Rights Assignment
2584 //   + double click "Lock pages in memory", add users and/or groups
2585 //   + reboot
2586 // Note the above steps are needed for administrator as well, as administrators
2587 // by default do not have the privilege to lock pages in memory.
2588 //
2589 // Note about Windows 2003: although the API supports committing large page
2590 // memory on a page-by-page basis and VirtualAlloc() returns success under this
2591 // scenario, I found through experiment it only uses large page if the entire
2592 // memory region is reserved and committed in a single VirtualAlloc() call.
2593 // This makes Windows large page support more or less like Solaris ISM, in
2594 // that the entire heap must be committed upfront. This probably will change
2595 // in the future, if so the code below needs to be revisited.
2596 
2597 #ifndef MEM_LARGE_PAGES
2598   #define MEM_LARGE_PAGES 0x20000000
2599 #endif
2600 
2601 static HANDLE    _hProcess;
2602 static HANDLE    _hToken;
2603 
2604 // Container for NUMA node list info
2605 class NUMANodeListHolder {
2606  private:
2607   int *_numa_used_node_list;  // allocated below
2608   int _numa_used_node_count;
2609 
2610   void free_node_list() {
2611     if (_numa_used_node_list != NULL) {
2612       FREE_C_HEAP_ARRAY(int, _numa_used_node_list);
2613     }
2614   }
2615 
2616  public:
2617   NUMANodeListHolder() {
2618     _numa_used_node_count = 0;
2619     _numa_used_node_list = NULL;
2620     // do rest of initialization in build routine (after function pointers are set up)
2621   }
2622 
2623   ~NUMANodeListHolder() {
2624     free_node_list();
2625   }
2626 
2627   bool build() {
2628     DWORD_PTR proc_aff_mask;
2629     DWORD_PTR sys_aff_mask;
2630     if (!GetProcessAffinityMask(GetCurrentProcess(), &proc_aff_mask, &sys_aff_mask)) return false;
2631     ULONG highest_node_number;
2632     if (!GetNumaHighestNodeNumber(&highest_node_number)) return false;
2633     free_node_list();
2634     _numa_used_node_list = NEW_C_HEAP_ARRAY(int, highest_node_number + 1, mtInternal);
2635     for (unsigned int i = 0; i <= highest_node_number; i++) {
2636       ULONGLONG proc_mask_numa_node;
2637       if (!GetNumaNodeProcessorMask(i, &proc_mask_numa_node)) return false;
2638       if ((proc_aff_mask & proc_mask_numa_node)!=0) {
2639         _numa_used_node_list[_numa_used_node_count++] = i;
2640       }
2641     }
2642     return (_numa_used_node_count > 1);
2643   }
2644 
2645   int get_count() { return _numa_used_node_count; }
2646   int get_node_list_entry(int n) {
2647     // for indexes out of range, returns -1
2648     return (n < _numa_used_node_count ? _numa_used_node_list[n] : -1);
2649   }
2650 
2651 } numa_node_list_holder;
2652 
2653 
2654 
2655 static size_t _large_page_size = 0;
2656 
2657 static bool request_lock_memory_privilege() {
2658   _hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE,
2659                           os::current_process_id());
2660 
2661   LUID luid;
2662   if (_hProcess != NULL &&
2663       OpenProcessToken(_hProcess, TOKEN_ADJUST_PRIVILEGES, &_hToken) &&
2664       LookupPrivilegeValue(NULL, "SeLockMemoryPrivilege", &luid)) {
2665 
2666     TOKEN_PRIVILEGES tp;
2667     tp.PrivilegeCount = 1;
2668     tp.Privileges[0].Luid = luid;
2669     tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
2670 
2671     // AdjustTokenPrivileges() may return TRUE even when it couldn't change the
2672     // privilege. Check GetLastError() too. See MSDN document.
2673     if (AdjustTokenPrivileges(_hToken, false, &tp, sizeof(tp), NULL, NULL) &&
2674         (GetLastError() == ERROR_SUCCESS)) {
2675       return true;
2676     }
2677   }
2678 
2679   return false;
2680 }
2681 
2682 static void cleanup_after_large_page_init() {
2683   if (_hProcess) CloseHandle(_hProcess);
2684   _hProcess = NULL;
2685   if (_hToken) CloseHandle(_hToken);
2686   _hToken = NULL;
2687 }
2688 
2689 static bool numa_interleaving_init() {
2690   bool success = false;
2691   bool use_numa_interleaving_specified = !FLAG_IS_DEFAULT(UseNUMAInterleaving);
2692 
2693   // print a warning if UseNUMAInterleaving flag is specified on command line
2694   bool warn_on_failure = use_numa_interleaving_specified;
2695 #define WARN(msg) if (warn_on_failure) { warning(msg); }
2696 
2697   // NUMAInterleaveGranularity cannot be less than vm_allocation_granularity (or _large_page_size if using large pages)
2698   size_t min_interleave_granularity = UseLargePages ? _large_page_size : os::vm_allocation_granularity();
2699   NUMAInterleaveGranularity = align_up(NUMAInterleaveGranularity, min_interleave_granularity);
2700 
2701   if (numa_node_list_holder.build()) {
2702     if (log_is_enabled(Debug, os, cpu)) {
2703       Log(os, cpu) log;
2704       log.debug("NUMA UsedNodeCount=%d, namely ", numa_node_list_holder.get_count());
2705       for (int i = 0; i < numa_node_list_holder.get_count(); i++) {
2706         log.debug("  %d ", numa_node_list_holder.get_node_list_entry(i));
2707       }
2708     }
2709     success = true;
2710   } else {
2711     WARN("Process does not cover multiple NUMA nodes.");
2712   }
2713   if (!success) {
2714     if (use_numa_interleaving_specified) WARN("...Ignoring UseNUMAInterleaving flag.");
2715   }
2716   return success;
2717 #undef WARN
2718 }
2719 
2720 // this routine is used whenever we need to reserve a contiguous VA range
2721 // but we need to make separate VirtualAlloc calls for each piece of the range
2722 // Reasons for doing this:
2723 //  * UseLargePagesIndividualAllocation was set (normally only needed on WS2003 but possible to be set otherwise)
2724 //  * UseNUMAInterleaving requires a separate node for each piece
2725 static char* allocate_pages_individually(size_t bytes, char* addr, DWORD flags,
2726                                          DWORD prot,
2727                                          bool should_inject_error = false) {
2728   char * p_buf;
2729   // note: at setup time we guaranteed that NUMAInterleaveGranularity was aligned up to a page size
2730   size_t page_size = UseLargePages ? _large_page_size : os::vm_allocation_granularity();
2731   size_t chunk_size = UseNUMAInterleaving ? NUMAInterleaveGranularity : page_size;
2732 
2733   // first reserve enough address space in advance since we want to be
2734   // able to break a single contiguous virtual address range into multiple
2735   // large page commits but WS2003 does not allow reserving large page space
2736   // so we just use 4K pages for reserve, this gives us a legal contiguous
2737   // address space. then we will deallocate that reservation, and re alloc
2738   // using large pages
2739   const size_t size_of_reserve = bytes + chunk_size;
2740   if (bytes > size_of_reserve) {
2741     // Overflowed.
2742     return NULL;
2743   }
2744   p_buf = (char *) VirtualAlloc(addr,
2745                                 size_of_reserve,  // size of Reserve
2746                                 MEM_RESERVE,
2747                                 PAGE_READWRITE);
2748   // If reservation failed, return NULL
2749   if (p_buf == NULL) return NULL;
2750   MemTracker::record_virtual_memory_reserve((address)p_buf, size_of_reserve, CALLER_PC);
2751   os::release_memory(p_buf, bytes + chunk_size);
2752 
2753   // we still need to round up to a page boundary (in case we are using large pages)
2754   // but not to a chunk boundary (in case InterleavingGranularity doesn't align with page size)
2755   // instead we handle this in the bytes_to_rq computation below
2756   p_buf = align_up(p_buf, page_size);
2757 
2758   // now go through and allocate one chunk at a time until all bytes are
2759   // allocated
2760   size_t  bytes_remaining = bytes;
2761   // An overflow of align_up() would have been caught above
2762   // in the calculation of size_of_reserve.
2763   char * next_alloc_addr = p_buf;
2764   HANDLE hProc = GetCurrentProcess();
2765 
2766 #ifdef ASSERT
2767   // Variable for the failure injection
2768   int ran_num = os::random();
2769   size_t fail_after = ran_num % bytes;
2770 #endif
2771 
2772   int count=0;
2773   while (bytes_remaining) {
2774     // select bytes_to_rq to get to the next chunk_size boundary
2775 
2776     size_t bytes_to_rq = MIN2(bytes_remaining, chunk_size - ((size_t)next_alloc_addr % chunk_size));
2777     // Note allocate and commit
2778     char * p_new;
2779 
2780 #ifdef ASSERT
2781     bool inject_error_now = should_inject_error && (bytes_remaining <= fail_after);
2782 #else
2783     const bool inject_error_now = false;
2784 #endif
2785 
2786     if (inject_error_now) {
2787       p_new = NULL;
2788     } else {
2789       if (!UseNUMAInterleaving) {
2790         p_new = (char *) VirtualAlloc(next_alloc_addr,
2791                                       bytes_to_rq,
2792                                       flags,
2793                                       prot);
2794       } else {
2795         // get the next node to use from the used_node_list
2796         assert(numa_node_list_holder.get_count() > 0, "Multiple NUMA nodes expected");
2797         DWORD node = numa_node_list_holder.get_node_list_entry(count % numa_node_list_holder.get_count());
2798         p_new = (char *)VirtualAllocExNuma(hProc, next_alloc_addr, bytes_to_rq, flags, prot, node);
2799       }
2800     }
2801 
2802     if (p_new == NULL) {
2803       // Free any allocated pages
2804       if (next_alloc_addr > p_buf) {
2805         // Some memory was committed so release it.
2806         size_t bytes_to_release = bytes - bytes_remaining;
2807         // NMT has yet to record any individual blocks, so it
2808         // need to create a dummy 'reserve' record to match
2809         // the release.
2810         MemTracker::record_virtual_memory_reserve((address)p_buf,
2811                                                   bytes_to_release, CALLER_PC);
2812         os::release_memory(p_buf, bytes_to_release);
2813       }
2814 #ifdef ASSERT
2815       if (should_inject_error) {
2816         log_develop_debug(pagesize)("Reserving pages individually failed.");
2817       }
2818 #endif
2819       return NULL;
2820     }
2821 
2822     bytes_remaining -= bytes_to_rq;
2823     next_alloc_addr += bytes_to_rq;
2824     count++;
2825   }
2826   // Although the memory is allocated individually, it is returned as one.
2827   // NMT records it as one block.
2828   if ((flags & MEM_COMMIT) != 0) {
2829     MemTracker::record_virtual_memory_reserve_and_commit((address)p_buf, bytes, CALLER_PC);
2830   } else {
2831     MemTracker::record_virtual_memory_reserve((address)p_buf, bytes, CALLER_PC);
2832   }
2833 
2834   // made it this far, success
2835   return p_buf;
2836 }
2837 
2838 
2839 
2840 void os::large_page_init() {
2841   if (!UseLargePages) return;
2842 
2843   // print a warning if any large page related flag is specified on command line
2844   bool warn_on_failure = !FLAG_IS_DEFAULT(UseLargePages) ||
2845                          !FLAG_IS_DEFAULT(LargePageSizeInBytes);
2846   bool success = false;
2847 
2848 #define WARN(msg) if (warn_on_failure) { warning(msg); }
2849   if (request_lock_memory_privilege()) {
2850     size_t s = GetLargePageMinimum();
2851     if (s) {
2852 #if defined(IA32) || defined(AMD64)
2853       if (s > 4*M || LargePageSizeInBytes > 4*M) {
2854         WARN("JVM cannot use large pages bigger than 4mb.");
2855       } else {
2856 #endif
2857         if (LargePageSizeInBytes && LargePageSizeInBytes % s == 0) {
2858           _large_page_size = LargePageSizeInBytes;
2859         } else {
2860           _large_page_size = s;
2861         }
2862         success = true;
2863 #if defined(IA32) || defined(AMD64)
2864       }
2865 #endif
2866     } else {
2867       WARN("Large page is not supported by the processor.");
2868     }
2869   } else {
2870     WARN("JVM cannot use large page memory because it does not have enough privilege to lock pages in memory.");
2871   }
2872 #undef WARN
2873 
2874   const size_t default_page_size = (size_t) vm_page_size();
2875   if (success && _large_page_size > default_page_size) {
2876     _page_sizes[0] = _large_page_size;
2877     _page_sizes[1] = default_page_size;
2878     _page_sizes[2] = 0;
2879   }
2880 
2881   cleanup_after_large_page_init();
2882   UseLargePages = success;
2883 }
2884 
2885 int os::create_file_for_heap(const char* dir) {
2886 
2887   const char name_template[] = "/jvmheap.XXXXXX";
2888   char *fullname = (char*)os::malloc((strlen(dir) + strlen(name_template) + 1), mtInternal);
2889   if (fullname == NULL) {
2890     vm_exit_during_initialization(err_msg("Malloc failed during creation of backing file for heap (%s)", os::strerror(errno)));
2891     return -1;
2892   }
2893 
2894   (void)strncpy(fullname, dir, strlen(dir)+1);
2895   (void)strncat(fullname, name_template, strlen(name_template));
2896 
2897   os::native_path(fullname);
2898 
2899   char *path = _mktemp(fullname);
2900   if (path == NULL) {
2901     warning("_mktemp could not create file name from template %s (%s)", fullname, os::strerror(errno));
2902     os::free(fullname);
2903     return -1;
2904   }
2905 
2906   int fd = _open(path, O_RDWR | O_CREAT | O_TEMPORARY | O_EXCL, S_IWRITE | S_IREAD);
2907 
2908   os::free(fullname);
2909   if (fd < 0) {
2910     warning("Problem opening file for heap (%s)", os::strerror(errno));
2911     return -1;
2912   }
2913   return fd;
2914 }
2915 
2916 // If 'base' is not NULL, function will return NULL if it cannot get 'base'
2917 char* os::map_memory_to_file(char* base, size_t size, int fd) {
2918   assert(fd != -1, "File descriptor is not valid");
2919 
2920   HANDLE fh = (HANDLE)_get_osfhandle(fd);
2921   HANDLE fileMapping = CreateFileMapping(fh, NULL, PAGE_READWRITE,
2922     (DWORD)(size >> 32), (DWORD)(size & 0xFFFFFFFF), NULL);
2923   if (fileMapping == NULL) {
2924     if (GetLastError() == ERROR_DISK_FULL) {
2925       vm_exit_during_initialization(err_msg("Could not allocate sufficient disk space for Java heap"));
2926     }
2927     else {
2928       vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
2929     }
2930 
2931     return NULL;
2932   }
2933 
2934   LPVOID addr = MapViewOfFileEx(fileMapping, FILE_MAP_WRITE, 0, 0, size, base);
2935 
2936   CloseHandle(fileMapping);
2937 
2938   return (char*)addr;
2939 }
2940 
2941 char* os::replace_existing_mapping_with_file_mapping(char* base, size_t size, int fd) {
2942   assert(fd != -1, "File descriptor is not valid");
2943   assert(base != NULL, "Base address cannot be NULL");
2944 
2945   release_memory(base, size);
2946   return map_memory_to_file(base, size, fd);
2947 }
2948 
2949 // On win32, one cannot release just a part of reserved memory, it's an
2950 // all or nothing deal.  When we split a reservation, we must break the
2951 // reservation into two reservations.
2952 void os::pd_split_reserved_memory(char *base, size_t size, size_t split,
2953                                   bool realloc) {
2954   if (size > 0) {
2955     release_memory(base, size);
2956     if (realloc) {
2957       reserve_memory(split, base);
2958     }
2959     if (size != split) {
2960       reserve_memory(size - split, base + split);
2961     }
2962   }
2963 }
2964 
2965 // Multiple threads can race in this code but it's not possible to unmap small sections of
2966 // virtual space to get requested alignment, like posix-like os's.
2967 // Windows prevents multiple thread from remapping over each other so this loop is thread-safe.
2968 char* os::reserve_memory_aligned(size_t size, size_t alignment, int file_desc) {
2969   assert((alignment & (os::vm_allocation_granularity() - 1)) == 0,
2970          "Alignment must be a multiple of allocation granularity (page size)");
2971   assert((size & (alignment -1)) == 0, "size must be 'alignment' aligned");
2972 
2973   size_t extra_size = size + alignment;
2974   assert(extra_size >= size, "overflow, size is too large to allow alignment");
2975 
2976   char* aligned_base = NULL;
2977 
2978   do {
2979     char* extra_base = os::reserve_memory(extra_size, NULL, alignment, file_desc);
2980     if (extra_base == NULL) {
2981       return NULL;
2982     }
2983     // Do manual alignment
2984     aligned_base = align_up(extra_base, alignment);
2985 
2986     if (file_desc != -1) {
2987       os::unmap_memory(extra_base, extra_size);
2988     } else {
2989       os::release_memory(extra_base, extra_size);
2990     }
2991 
2992     aligned_base = os::reserve_memory(size, aligned_base, 0, file_desc);
2993 
2994   } while (aligned_base == NULL);
2995 
2996   return aligned_base;
2997 }
2998 
2999 char* os::pd_reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
3000   assert((size_t)addr % os::vm_allocation_granularity() == 0,
3001          "reserve alignment");
3002   assert(bytes % os::vm_page_size() == 0, "reserve page size");
3003   char* res;
3004   // note that if UseLargePages is on, all the areas that require interleaving
3005   // will go thru reserve_memory_special rather than thru here.
3006   bool use_individual = (UseNUMAInterleaving && !UseLargePages);
3007   if (!use_individual) {
3008     res = (char*)VirtualAlloc(addr, bytes, MEM_RESERVE, PAGE_READWRITE);
3009   } else {
3010     elapsedTimer reserveTimer;
3011     if (Verbose && PrintMiscellaneous) reserveTimer.start();
3012     // in numa interleaving, we have to allocate pages individually
3013     // (well really chunks of NUMAInterleaveGranularity size)
3014     res = allocate_pages_individually(bytes, addr, MEM_RESERVE, PAGE_READWRITE);
3015     if (res == NULL) {
3016       warning("NUMA page allocation failed");
3017     }
3018     if (Verbose && PrintMiscellaneous) {
3019       reserveTimer.stop();
3020       tty->print_cr("reserve_memory of %Ix bytes took " JLONG_FORMAT " ms (" JLONG_FORMAT " ticks)", bytes,
3021                     reserveTimer.milliseconds(), reserveTimer.ticks());
3022     }
3023   }
3024   assert(res == NULL || addr == NULL || addr == res,
3025          "Unexpected address from reserve.");
3026 
3027   return res;
3028 }
3029 
3030 // Reserve memory at an arbitrary address, only if that area is
3031 // available (and not reserved for something else).
3032 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
3033   // Windows os::reserve_memory() fails of the requested address range is
3034   // not avilable.
3035   return reserve_memory(bytes, requested_addr);
3036 }
3037 
3038 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
3039   assert(file_desc >= 0, "file_desc is not valid");
3040   return map_memory_to_file(requested_addr, bytes, file_desc);
3041 }
3042 
3043 size_t os::large_page_size() {
3044   return _large_page_size;
3045 }
3046 
3047 bool os::can_commit_large_page_memory() {
3048   // Windows only uses large page memory when the entire region is reserved
3049   // and committed in a single VirtualAlloc() call. This may change in the
3050   // future, but with Windows 2003 it's not possible to commit on demand.
3051   return false;
3052 }
3053 
3054 bool os::can_execute_large_page_memory() {
3055   return true;
3056 }
3057 
3058 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* addr,
3059                                  bool exec) {
3060   assert(UseLargePages, "only for large pages");
3061 
3062   if (!is_aligned(bytes, os::large_page_size()) || alignment > os::large_page_size()) {
3063     return NULL; // Fallback to small pages.
3064   }
3065 
3066   const DWORD prot = exec ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
3067   const DWORD flags = MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES;
3068 
3069   // with large pages, there are two cases where we need to use Individual Allocation
3070   // 1) the UseLargePagesIndividualAllocation flag is set (set by default on WS2003)
3071   // 2) NUMA Interleaving is enabled, in which case we use a different node for each page
3072   if (UseLargePagesIndividualAllocation || UseNUMAInterleaving) {
3073     log_debug(pagesize)("Reserving large pages individually.");
3074 
3075     char * p_buf = allocate_pages_individually(bytes, addr, flags, prot, LargePagesIndividualAllocationInjectError);
3076     if (p_buf == NULL) {
3077       // give an appropriate warning message
3078       if (UseNUMAInterleaving) {
3079         warning("NUMA large page allocation failed, UseLargePages flag ignored");
3080       }
3081       if (UseLargePagesIndividualAllocation) {
3082         warning("Individually allocated large pages failed, "
3083                 "use -XX:-UseLargePagesIndividualAllocation to turn off");
3084       }
3085       return NULL;
3086     }
3087 
3088     return p_buf;
3089 
3090   } else {
3091     log_debug(pagesize)("Reserving large pages in a single large chunk.");
3092 
3093     // normal policy just allocate it all at once
3094     DWORD flag = MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES;
3095     char * res = (char *)VirtualAlloc(addr, bytes, flag, prot);
3096     if (res != NULL) {
3097       MemTracker::record_virtual_memory_reserve_and_commit((address)res, bytes, CALLER_PC);
3098     }
3099 
3100     return res;
3101   }
3102 }
3103 
3104 bool os::release_memory_special(char* base, size_t bytes) {
3105   assert(base != NULL, "Sanity check");
3106   return release_memory(base, bytes);
3107 }
3108 
3109 void os::print_statistics() {
3110 }
3111 
3112 static void warn_fail_commit_memory(char* addr, size_t bytes, bool exec) {
3113   int err = os::get_last_error();
3114   char buf[256];
3115   size_t buf_len = os::lasterror(buf, sizeof(buf));
3116   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
3117           ", %d) failed; error='%s' (DOS error/errno=%d)", addr, bytes,
3118           exec, buf_len != 0 ? buf : "<no_error_string>", err);
3119 }
3120 
3121 bool os::pd_commit_memory(char* addr, size_t bytes, bool exec) {
3122   if (bytes == 0) {
3123     // Don't bother the OS with noops.
3124     return true;
3125   }
3126   assert((size_t) addr % os::vm_page_size() == 0, "commit on page boundaries");
3127   assert(bytes % os::vm_page_size() == 0, "commit in page-sized chunks");
3128   // Don't attempt to print anything if the OS call fails. We're
3129   // probably low on resources, so the print itself may cause crashes.
3130 
3131   // unless we have NUMAInterleaving enabled, the range of a commit
3132   // is always within a reserve covered by a single VirtualAlloc
3133   // in that case we can just do a single commit for the requested size
3134   if (!UseNUMAInterleaving) {
3135     if (VirtualAlloc(addr, bytes, MEM_COMMIT, PAGE_READWRITE) == NULL) {
3136       NOT_PRODUCT(warn_fail_commit_memory(addr, bytes, exec);)
3137       return false;
3138     }
3139     if (exec) {
3140       DWORD oldprot;
3141       // Windows doc says to use VirtualProtect to get execute permissions
3142       if (!VirtualProtect(addr, bytes, PAGE_EXECUTE_READWRITE, &oldprot)) {
3143         NOT_PRODUCT(warn_fail_commit_memory(addr, bytes, exec);)
3144         return false;
3145       }
3146     }
3147     return true;
3148   } else {
3149 
3150     // when NUMAInterleaving is enabled, the commit might cover a range that
3151     // came from multiple VirtualAlloc reserves (using allocate_pages_individually).
3152     // VirtualQuery can help us determine that.  The RegionSize that VirtualQuery
3153     // returns represents the number of bytes that can be committed in one step.
3154     size_t bytes_remaining = bytes;
3155     char * next_alloc_addr = addr;
3156     while (bytes_remaining > 0) {
3157       MEMORY_BASIC_INFORMATION alloc_info;
3158       VirtualQuery(next_alloc_addr, &alloc_info, sizeof(alloc_info));
3159       size_t bytes_to_rq = MIN2(bytes_remaining, (size_t)alloc_info.RegionSize);
3160       if (VirtualAlloc(next_alloc_addr, bytes_to_rq, MEM_COMMIT,
3161                        PAGE_READWRITE) == NULL) {
3162         NOT_PRODUCT(warn_fail_commit_memory(next_alloc_addr, bytes_to_rq,
3163                                             exec);)
3164         return false;
3165       }
3166       if (exec) {
3167         DWORD oldprot;
3168         if (!VirtualProtect(next_alloc_addr, bytes_to_rq,
3169                             PAGE_EXECUTE_READWRITE, &oldprot)) {
3170           NOT_PRODUCT(warn_fail_commit_memory(next_alloc_addr, bytes_to_rq,
3171                                               exec);)
3172           return false;
3173         }
3174       }
3175       bytes_remaining -= bytes_to_rq;
3176       next_alloc_addr += bytes_to_rq;
3177     }
3178   }
3179   // if we made it this far, return true
3180   return true;
3181 }
3182 
3183 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
3184                           bool exec) {
3185   // alignment_hint is ignored on this OS
3186   return pd_commit_memory(addr, size, exec);
3187 }
3188 
3189 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
3190                                   const char* mesg) {
3191   assert(mesg != NULL, "mesg must be specified");
3192   if (!pd_commit_memory(addr, size, exec)) {
3193     warn_fail_commit_memory(addr, size, exec);
3194     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
3195   }
3196 }
3197 
3198 void os::pd_commit_memory_or_exit(char* addr, size_t size,
3199                                   size_t alignment_hint, bool exec,
3200                                   const char* mesg) {
3201   // alignment_hint is ignored on this OS
3202   pd_commit_memory_or_exit(addr, size, exec, mesg);
3203 }
3204 
3205 bool os::pd_uncommit_memory(char* addr, size_t bytes) {
3206   if (bytes == 0) {
3207     // Don't bother the OS with noops.
3208     return true;
3209   }
3210   assert((size_t) addr % os::vm_page_size() == 0, "uncommit on page boundaries");
3211   assert(bytes % os::vm_page_size() == 0, "uncommit in page-sized chunks");
3212   return (VirtualFree(addr, bytes, MEM_DECOMMIT) != 0);
3213 }
3214 
3215 bool os::pd_release_memory(char* addr, size_t bytes) {
3216   return VirtualFree(addr, 0, MEM_RELEASE) != 0;
3217 }
3218 
3219 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
3220   return os::commit_memory(addr, size, !ExecMem);
3221 }
3222 
3223 bool os::remove_stack_guard_pages(char* addr, size_t size) {
3224   return os::uncommit_memory(addr, size);
3225 }
3226 
3227 static bool protect_pages_individually(char* addr, size_t bytes, unsigned int p, DWORD *old_status) {
3228   uint count = 0;
3229   bool ret = false;
3230   size_t bytes_remaining = bytes;
3231   char * next_protect_addr = addr;
3232 
3233   // Use VirtualQuery() to get the chunk size.
3234   while (bytes_remaining) {
3235     MEMORY_BASIC_INFORMATION alloc_info;
3236     if (VirtualQuery(next_protect_addr, &alloc_info, sizeof(alloc_info)) == 0) {
3237       return false;
3238     }
3239 
3240     size_t bytes_to_protect = MIN2(bytes_remaining, (size_t)alloc_info.RegionSize);
3241     // We used different API at allocate_pages_individually() based on UseNUMAInterleaving,
3242     // but we don't distinguish here as both cases are protected by same API.
3243     ret = VirtualProtect(next_protect_addr, bytes_to_protect, p, old_status) != 0;
3244     warning("Failed protecting pages individually for chunk #%u", count);
3245     if (!ret) {
3246       return false;
3247     }
3248 
3249     bytes_remaining -= bytes_to_protect;
3250     next_protect_addr += bytes_to_protect;
3251     count++;
3252   }
3253   return ret;
3254 }
3255 
3256 // Set protections specified
3257 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
3258                         bool is_committed) {
3259   unsigned int p = 0;
3260   switch (prot) {
3261   case MEM_PROT_NONE: p = PAGE_NOACCESS; break;
3262   case MEM_PROT_READ: p = PAGE_READONLY; break;
3263   case MEM_PROT_RW:   p = PAGE_READWRITE; break;
3264   case MEM_PROT_RWX:  p = PAGE_EXECUTE_READWRITE; break;
3265   default:
3266     ShouldNotReachHere();
3267   }
3268 
3269   DWORD old_status;
3270 
3271   // Strange enough, but on Win32 one can change protection only for committed
3272   // memory, not a big deal anyway, as bytes less or equal than 64K
3273   if (!is_committed) {
3274     commit_memory_or_exit(addr, bytes, prot == MEM_PROT_RWX,
3275                           "cannot commit protection page");
3276   }
3277   // One cannot use os::guard_memory() here, as on Win32 guard page
3278   // have different (one-shot) semantics, from MSDN on PAGE_GUARD:
3279   //
3280   // Pages in the region become guard pages. Any attempt to access a guard page
3281   // causes the system to raise a STATUS_GUARD_PAGE exception and turn off
3282   // the guard page status. Guard pages thus act as a one-time access alarm.
3283   bool ret;
3284   if (UseNUMAInterleaving) {
3285     // If UseNUMAInterleaving is enabled, the pages may have been allocated a chunk at a time,
3286     // so we must protect the chunks individually.
3287     ret = protect_pages_individually(addr, bytes, p, &old_status);
3288   } else {
3289     ret = VirtualProtect(addr, bytes, p, &old_status) != 0;
3290   }
3291 #ifdef ASSERT
3292   if (!ret) {
3293     int err = os::get_last_error();
3294     char buf[256];
3295     size_t buf_len = os::lasterror(buf, sizeof(buf));
3296     warning("INFO: os::protect_memory(" PTR_FORMAT ", " SIZE_FORMAT
3297           ") failed; error='%s' (DOS error/errno=%d)", addr, bytes,
3298           buf_len != 0 ? buf : "<no_error_string>", err);
3299   }
3300 #endif
3301   return ret;
3302 }
3303 
3304 bool os::guard_memory(char* addr, size_t bytes) {
3305   DWORD old_status;
3306   return VirtualProtect(addr, bytes, PAGE_READWRITE | PAGE_GUARD, &old_status) != 0;
3307 }
3308 
3309 bool os::unguard_memory(char* addr, size_t bytes) {
3310   DWORD old_status;
3311   return VirtualProtect(addr, bytes, PAGE_READWRITE, &old_status) != 0;
3312 }
3313 
3314 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { }
3315 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { }
3316 void os::numa_make_global(char *addr, size_t bytes)    { }
3317 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint)    { }
3318 bool os::numa_topology_changed()                       { return false; }
3319 size_t os::numa_get_groups_num()                       { return MAX2(numa_node_list_holder.get_count(), 1); }
3320 int os::numa_get_group_id()                            { return 0; }
3321 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
3322   if (numa_node_list_holder.get_count() == 0 && size > 0) {
3323     // Provide an answer for UMA systems
3324     ids[0] = 0;
3325     return 1;
3326   } else {
3327     // check for size bigger than actual groups_num
3328     size = MIN2(size, numa_get_groups_num());
3329     for (int i = 0; i < (int)size; i++) {
3330       ids[i] = numa_node_list_holder.get_node_list_entry(i);
3331     }
3332     return size;
3333   }
3334 }
3335 
3336 bool os::get_page_info(char *start, page_info* info) {
3337   return false;
3338 }
3339 
3340 char *os::scan_pages(char *start, char* end, page_info* page_expected,
3341                      page_info* page_found) {
3342   return end;
3343 }
3344 
3345 char* os::non_memory_address_word() {
3346   // Must never look like an address returned by reserve_memory,
3347   // even in its subfields (as defined by the CPU immediate fields,
3348   // if the CPU splits constants across multiple instructions).
3349   return (char*)-1;
3350 }
3351 
3352 #define MAX_ERROR_COUNT 100
3353 #define SYS_THREAD_ERROR 0xffffffffUL
3354 
3355 void os::pd_start_thread(Thread* thread) {
3356   DWORD ret = ResumeThread(thread->osthread()->thread_handle());
3357   // Returns previous suspend state:
3358   // 0:  Thread was not suspended
3359   // 1:  Thread is running now
3360   // >1: Thread is still suspended.
3361   assert(ret != SYS_THREAD_ERROR, "StartThread failed"); // should propagate back
3362 }
3363 
3364 class HighResolutionInterval : public CHeapObj<mtThread> {
3365   // The default timer resolution seems to be 10 milliseconds.
3366   // (Where is this written down?)
3367   // If someone wants to sleep for only a fraction of the default,
3368   // then we set the timer resolution down to 1 millisecond for
3369   // the duration of their interval.
3370   // We carefully set the resolution back, since otherwise we
3371   // seem to incur an overhead (3%?) that we don't need.
3372   // CONSIDER: if ms is small, say 3, then we should run with a high resolution time.
3373   // Buf if ms is large, say 500, or 503, we should avoid the call to timeBeginPeriod().
3374   // Alternatively, we could compute the relative error (503/500 = .6%) and only use
3375   // timeBeginPeriod() if the relative error exceeded some threshold.
3376   // timeBeginPeriod() has been linked to problems with clock drift on win32 systems and
3377   // to decreased efficiency related to increased timer "tick" rates.  We want to minimize
3378   // (a) calls to timeBeginPeriod() and timeEndPeriod() and (b) time spent with high
3379   // resolution timers running.
3380  private:
3381   jlong resolution;
3382  public:
3383   HighResolutionInterval(jlong ms) {
3384     resolution = ms % 10L;
3385     if (resolution != 0) {
3386       MMRESULT result = timeBeginPeriod(1L);
3387     }
3388   }
3389   ~HighResolutionInterval() {
3390     if (resolution != 0) {
3391       MMRESULT result = timeEndPeriod(1L);
3392     }
3393     resolution = 0L;
3394   }
3395 };
3396 
3397 int os::sleep(Thread* thread, jlong ms, bool interruptable) {
3398   jlong limit = (jlong) MAXDWORD;
3399 
3400   while (ms > limit) {
3401     int res;
3402     if ((res = sleep(thread, limit, interruptable)) != OS_TIMEOUT) {
3403       return res;
3404     }
3405     ms -= limit;
3406   }
3407 
3408   assert(thread == Thread::current(), "thread consistency check");
3409   OSThread* osthread = thread->osthread();
3410   OSThreadWaitState osts(osthread, false /* not Object.wait() */);
3411   int result;
3412   if (interruptable) {
3413     assert(thread->is_Java_thread(), "must be java thread");
3414     JavaThread *jt = (JavaThread *) thread;
3415     ThreadBlockInVM tbivm(jt);
3416 
3417     jt->set_suspend_equivalent();
3418     // cleared by handle_special_suspend_equivalent_condition() or
3419     // java_suspend_self() via check_and_wait_while_suspended()
3420 
3421     HANDLE events[1];
3422     events[0] = osthread->interrupt_event();
3423     HighResolutionInterval *phri=NULL;
3424     if (!ForceTimeHighResolution) {
3425       phri = new HighResolutionInterval(ms);
3426     }
3427     if (WaitForMultipleObjects(1, events, FALSE, (DWORD)ms) == WAIT_TIMEOUT) {
3428       result = OS_TIMEOUT;
3429     } else {
3430       ResetEvent(osthread->interrupt_event());
3431       osthread->set_interrupted(false);
3432       result = OS_INTRPT;
3433     }
3434     delete phri; //if it is NULL, harmless
3435 
3436     // were we externally suspended while we were waiting?
3437     jt->check_and_wait_while_suspended();
3438   } else {
3439     assert(!thread->is_Java_thread(), "must not be java thread");
3440     Sleep((long) ms);
3441     result = OS_TIMEOUT;
3442   }
3443   return result;
3444 }
3445 
3446 // Short sleep, direct OS call.
3447 //
3448 // ms = 0, means allow others (if any) to run.
3449 //
3450 void os::naked_short_sleep(jlong ms) {
3451   assert(ms < 1000, "Un-interruptable sleep, short time use only");
3452   Sleep(ms);
3453 }
3454 
3455 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
3456 void os::infinite_sleep() {
3457   while (true) {    // sleep forever ...
3458     Sleep(100000);  // ... 100 seconds at a time
3459   }
3460 }
3461 
3462 typedef BOOL (WINAPI * STTSignature)(void);
3463 
3464 void os::naked_yield() {
3465   // Consider passing back the return value from SwitchToThread().
3466   SwitchToThread();
3467 }
3468 
3469 // Win32 only gives you access to seven real priorities at a time,
3470 // so we compress Java's ten down to seven.  It would be better
3471 // if we dynamically adjusted relative priorities.
3472 
3473 int os::java_to_os_priority[CriticalPriority + 1] = {
3474   THREAD_PRIORITY_IDLE,                         // 0  Entry should never be used
3475   THREAD_PRIORITY_LOWEST,                       // 1  MinPriority
3476   THREAD_PRIORITY_LOWEST,                       // 2
3477   THREAD_PRIORITY_BELOW_NORMAL,                 // 3
3478   THREAD_PRIORITY_BELOW_NORMAL,                 // 4
3479   THREAD_PRIORITY_NORMAL,                       // 5  NormPriority
3480   THREAD_PRIORITY_NORMAL,                       // 6
3481   THREAD_PRIORITY_ABOVE_NORMAL,                 // 7
3482   THREAD_PRIORITY_ABOVE_NORMAL,                 // 8
3483   THREAD_PRIORITY_HIGHEST,                      // 9  NearMaxPriority
3484   THREAD_PRIORITY_HIGHEST,                      // 10 MaxPriority
3485   THREAD_PRIORITY_HIGHEST                       // 11 CriticalPriority
3486 };
3487 
3488 int prio_policy1[CriticalPriority + 1] = {
3489   THREAD_PRIORITY_IDLE,                         // 0  Entry should never be used
3490   THREAD_PRIORITY_LOWEST,                       // 1  MinPriority
3491   THREAD_PRIORITY_LOWEST,                       // 2
3492   THREAD_PRIORITY_BELOW_NORMAL,                 // 3
3493   THREAD_PRIORITY_BELOW_NORMAL,                 // 4
3494   THREAD_PRIORITY_NORMAL,                       // 5  NormPriority
3495   THREAD_PRIORITY_ABOVE_NORMAL,                 // 6
3496   THREAD_PRIORITY_ABOVE_NORMAL,                 // 7
3497   THREAD_PRIORITY_HIGHEST,                      // 8
3498   THREAD_PRIORITY_HIGHEST,                      // 9  NearMaxPriority
3499   THREAD_PRIORITY_TIME_CRITICAL,                // 10 MaxPriority
3500   THREAD_PRIORITY_TIME_CRITICAL                 // 11 CriticalPriority
3501 };
3502 
3503 static int prio_init() {
3504   // If ThreadPriorityPolicy is 1, switch tables
3505   if (ThreadPriorityPolicy == 1) {
3506     int i;
3507     for (i = 0; i < CriticalPriority + 1; i++) {
3508       os::java_to_os_priority[i] = prio_policy1[i];
3509     }
3510   }
3511   if (UseCriticalJavaThreadPriority) {
3512     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
3513   }
3514   return 0;
3515 }
3516 
3517 OSReturn os::set_native_priority(Thread* thread, int priority) {
3518   if (!UseThreadPriorities) return OS_OK;
3519   bool ret = SetThreadPriority(thread->osthread()->thread_handle(), priority) != 0;
3520   return ret ? OS_OK : OS_ERR;
3521 }
3522 
3523 OSReturn os::get_native_priority(const Thread* const thread,
3524                                  int* priority_ptr) {
3525   if (!UseThreadPriorities) {
3526     *priority_ptr = java_to_os_priority[NormPriority];
3527     return OS_OK;
3528   }
3529   int os_prio = GetThreadPriority(thread->osthread()->thread_handle());
3530   if (os_prio == THREAD_PRIORITY_ERROR_RETURN) {
3531     assert(false, "GetThreadPriority failed");
3532     return OS_ERR;
3533   }
3534   *priority_ptr = os_prio;
3535   return OS_OK;
3536 }
3537 
3538 
3539 // Hint to the underlying OS that a task switch would not be good.
3540 // Void return because it's a hint and can fail.
3541 void os::hint_no_preempt() {}
3542 
3543 void os::interrupt(Thread* thread) {
3544   assert(!thread->is_Java_thread() || Thread::current() == thread ||
3545          Threads_lock->owned_by_self(),
3546          "possibility of dangling Thread pointer");
3547 
3548   OSThread* osthread = thread->osthread();
3549   osthread->set_interrupted(true);
3550   // More than one thread can get here with the same value of osthread,
3551   // resulting in multiple notifications.  We do, however, want the store
3552   // to interrupted() to be visible to other threads before we post
3553   // the interrupt event.
3554   OrderAccess::release();
3555   SetEvent(osthread->interrupt_event());
3556   // For JSR166:  unpark after setting status
3557   if (thread->is_Java_thread()) {
3558     ((JavaThread*)thread)->parker()->unpark();
3559   }
3560 
3561   ParkEvent * ev = thread->_ParkEvent;
3562   if (ev != NULL) ev->unpark();
3563 }
3564 
3565 
3566 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
3567   assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
3568          "possibility of dangling Thread pointer");
3569 
3570   OSThread* osthread = thread->osthread();
3571   // There is no synchronization between the setting of the interrupt
3572   // and it being cleared here. It is critical - see 6535709 - that
3573   // we only clear the interrupt state, and reset the interrupt event,
3574   // if we are going to report that we were indeed interrupted - else
3575   // an interrupt can be "lost", leading to spurious wakeups or lost wakeups
3576   // depending on the timing. By checking thread interrupt event to see
3577   // if the thread gets real interrupt thus prevent spurious wakeup.
3578   bool interrupted = osthread->interrupted() && (WaitForSingleObject(osthread->interrupt_event(), 0) == WAIT_OBJECT_0);
3579   if (interrupted && clear_interrupted) {
3580     osthread->set_interrupted(false);
3581     ResetEvent(osthread->interrupt_event());
3582   } // Otherwise leave the interrupted state alone
3583 
3584   return interrupted;
3585 }
3586 
3587 // GetCurrentThreadId() returns DWORD
3588 intx os::current_thread_id()  { return GetCurrentThreadId(); }
3589 
3590 static int _initial_pid = 0;
3591 
3592 int os::current_process_id() {
3593   return (_initial_pid ? _initial_pid : _getpid());
3594 }
3595 
3596 int    os::win32::_vm_page_size              = 0;
3597 int    os::win32::_vm_allocation_granularity = 0;
3598 int    os::win32::_processor_type            = 0;
3599 // Processor level is not available on non-NT systems, use vm_version instead
3600 int    os::win32::_processor_level           = 0;
3601 julong os::win32::_physical_memory           = 0;
3602 size_t os::win32::_default_stack_size        = 0;
3603 
3604 intx          os::win32::_os_thread_limit    = 0;
3605 volatile intx os::win32::_os_thread_count    = 0;
3606 
3607 bool   os::win32::_is_windows_server         = false;
3608 
3609 // 6573254
3610 // Currently, the bug is observed across all the supported Windows releases,
3611 // including the latest one (as of this writing - Windows Server 2012 R2)
3612 bool   os::win32::_has_exit_bug              = true;
3613 
3614 void os::win32::initialize_system_info() {
3615   SYSTEM_INFO si;
3616   GetSystemInfo(&si);
3617   _vm_page_size    = si.dwPageSize;
3618   _vm_allocation_granularity = si.dwAllocationGranularity;
3619   _processor_type  = si.dwProcessorType;
3620   _processor_level = si.wProcessorLevel;
3621   set_processor_count(si.dwNumberOfProcessors);
3622 
3623   MEMORYSTATUSEX ms;
3624   ms.dwLength = sizeof(ms);
3625 
3626   // also returns dwAvailPhys (free physical memory bytes), dwTotalVirtual, dwAvailVirtual,
3627   // dwMemoryLoad (% of memory in use)
3628   GlobalMemoryStatusEx(&ms);
3629   _physical_memory = ms.ullTotalPhys;
3630 
3631   if (FLAG_IS_DEFAULT(MaxRAM)) {
3632     // Adjust MaxRAM according to the maximum virtual address space available.
3633     FLAG_SET_DEFAULT(MaxRAM, MIN2(MaxRAM, (uint64_t) ms.ullTotalVirtual));
3634   }
3635 
3636   OSVERSIONINFOEX oi;
3637   oi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
3638   GetVersionEx((OSVERSIONINFO*)&oi);
3639   switch (oi.dwPlatformId) {
3640   case VER_PLATFORM_WIN32_NT:
3641     {
3642       int os_vers = oi.dwMajorVersion * 1000 + oi.dwMinorVersion;
3643       if (oi.wProductType == VER_NT_DOMAIN_CONTROLLER ||
3644           oi.wProductType == VER_NT_SERVER) {
3645         _is_windows_server = true;
3646       }
3647     }
3648     break;
3649   default: fatal("Unknown platform");
3650   }
3651 
3652   _default_stack_size = os::current_stack_size();
3653   assert(_default_stack_size > (size_t) _vm_page_size, "invalid stack size");
3654   assert((_default_stack_size & (_vm_page_size - 1)) == 0,
3655          "stack size not a multiple of page size");
3656 
3657   initialize_performance_counter();
3658 }
3659 
3660 
3661 HINSTANCE os::win32::load_Windows_dll(const char* name, char *ebuf,
3662                                       int ebuflen) {
3663   char path[MAX_PATH];
3664   DWORD size;
3665   DWORD pathLen = (DWORD)sizeof(path);
3666   HINSTANCE result = NULL;
3667 
3668   // only allow library name without path component
3669   assert(strchr(name, '\\') == NULL, "path not allowed");
3670   assert(strchr(name, ':') == NULL, "path not allowed");
3671   if (strchr(name, '\\') != NULL || strchr(name, ':') != NULL) {
3672     jio_snprintf(ebuf, ebuflen,
3673                  "Invalid parameter while calling os::win32::load_windows_dll(): cannot take path: %s", name);
3674     return NULL;
3675   }
3676 
3677   // search system directory
3678   if ((size = GetSystemDirectory(path, pathLen)) > 0) {
3679     if (size >= pathLen) {
3680       return NULL; // truncated
3681     }
3682     if (jio_snprintf(path + size, pathLen - size, "\\%s", name) == -1) {
3683       return NULL; // truncated
3684     }
3685     if ((result = (HINSTANCE)os::dll_load(path, ebuf, ebuflen)) != NULL) {
3686       return result;
3687     }
3688   }
3689 
3690   // try Windows directory
3691   if ((size = GetWindowsDirectory(path, pathLen)) > 0) {
3692     if (size >= pathLen) {
3693       return NULL; // truncated
3694     }
3695     if (jio_snprintf(path + size, pathLen - size, "\\%s", name) == -1) {
3696       return NULL; // truncated
3697     }
3698     if ((result = (HINSTANCE)os::dll_load(path, ebuf, ebuflen)) != NULL) {
3699       return result;
3700     }
3701   }
3702 
3703   jio_snprintf(ebuf, ebuflen,
3704                "os::win32::load_windows_dll() cannot load %s from system directories.", name);
3705   return NULL;
3706 }
3707 
3708 #define MAXIMUM_THREADS_TO_KEEP (16 * MAXIMUM_WAIT_OBJECTS)
3709 #define EXIT_TIMEOUT 300000 /* 5 minutes */
3710 
3711 static BOOL CALLBACK init_crit_sect_call(PINIT_ONCE, PVOID pcrit_sect, PVOID*) {
3712   InitializeCriticalSection((CRITICAL_SECTION*)pcrit_sect);
3713   return TRUE;
3714 }
3715 
3716 int os::win32::exit_process_or_thread(Ept what, int exit_code) {
3717   // Basic approach:
3718   //  - Each exiting thread registers its intent to exit and then does so.
3719   //  - A thread trying to terminate the process must wait for all
3720   //    threads currently exiting to complete their exit.
3721 
3722   if (os::win32::has_exit_bug()) {
3723     // The array holds handles of the threads that have started exiting by calling
3724     // _endthreadex().
3725     // Should be large enough to avoid blocking the exiting thread due to lack of
3726     // a free slot.
3727     static HANDLE handles[MAXIMUM_THREADS_TO_KEEP];
3728     static int handle_count = 0;
3729 
3730     static INIT_ONCE init_once_crit_sect = INIT_ONCE_STATIC_INIT;
3731     static CRITICAL_SECTION crit_sect;
3732     static volatile DWORD process_exiting = 0;
3733     int i, j;
3734     DWORD res;
3735     HANDLE hproc, hthr;
3736 
3737     // We only attempt to register threads until a process exiting
3738     // thread manages to set the process_exiting flag. Any threads
3739     // that come through here after the process_exiting flag is set
3740     // are unregistered and will be caught in the SuspendThread()
3741     // infinite loop below.
3742     bool registered = false;
3743 
3744     // The first thread that reached this point, initializes the critical section.
3745     if (!InitOnceExecuteOnce(&init_once_crit_sect, init_crit_sect_call, &crit_sect, NULL)) {
3746       warning("crit_sect initialization failed in %s: %d\n", __FILE__, __LINE__);
3747     } else if (OrderAccess::load_acquire(&process_exiting) == 0) {
3748       if (what != EPT_THREAD) {
3749         // Atomically set process_exiting before the critical section
3750         // to increase the visibility between racing threads.
3751         Atomic::cmpxchg(GetCurrentThreadId(), &process_exiting, (DWORD)0);
3752       }
3753       EnterCriticalSection(&crit_sect);
3754 
3755       if (what == EPT_THREAD && OrderAccess::load_acquire(&process_exiting) == 0) {
3756         // Remove from the array those handles of the threads that have completed exiting.
3757         for (i = 0, j = 0; i < handle_count; ++i) {
3758           res = WaitForSingleObject(handles[i], 0 /* don't wait */);
3759           if (res == WAIT_TIMEOUT) {
3760             handles[j++] = handles[i];
3761           } else {
3762             if (res == WAIT_FAILED) {
3763               warning("WaitForSingleObject failed (%u) in %s: %d\n",
3764                       GetLastError(), __FILE__, __LINE__);
3765             }
3766             // Don't keep the handle, if we failed waiting for it.
3767             CloseHandle(handles[i]);
3768           }
3769         }
3770 
3771         // If there's no free slot in the array of the kept handles, we'll have to
3772         // wait until at least one thread completes exiting.
3773         if ((handle_count = j) == MAXIMUM_THREADS_TO_KEEP) {
3774           // Raise the priority of the oldest exiting thread to increase its chances
3775           // to complete sooner.
3776           SetThreadPriority(handles[0], THREAD_PRIORITY_ABOVE_NORMAL);
3777           res = WaitForMultipleObjects(MAXIMUM_WAIT_OBJECTS, handles, FALSE, EXIT_TIMEOUT);
3778           if (res >= WAIT_OBJECT_0 && res < (WAIT_OBJECT_0 + MAXIMUM_WAIT_OBJECTS)) {
3779             i = (res - WAIT_OBJECT_0);
3780             handle_count = MAXIMUM_THREADS_TO_KEEP - 1;
3781             for (; i < handle_count; ++i) {
3782               handles[i] = handles[i + 1];
3783             }
3784           } else {
3785             warning("WaitForMultipleObjects %s (%u) in %s: %d\n",
3786                     (res == WAIT_FAILED ? "failed" : "timed out"),
3787                     GetLastError(), __FILE__, __LINE__);
3788             // Don't keep handles, if we failed waiting for them.
3789             for (i = 0; i < MAXIMUM_THREADS_TO_KEEP; ++i) {
3790               CloseHandle(handles[i]);
3791             }
3792             handle_count = 0;
3793           }
3794         }
3795 
3796         // Store a duplicate of the current thread handle in the array of handles.
3797         hproc = GetCurrentProcess();
3798         hthr = GetCurrentThread();
3799         if (!DuplicateHandle(hproc, hthr, hproc, &handles[handle_count],
3800                              0, FALSE, DUPLICATE_SAME_ACCESS)) {
3801           warning("DuplicateHandle failed (%u) in %s: %d\n",
3802                   GetLastError(), __FILE__, __LINE__);
3803 
3804           // We can't register this thread (no more handles) so this thread
3805           // may be racing with a thread that is calling exit(). If the thread
3806           // that is calling exit() has managed to set the process_exiting
3807           // flag, then this thread will be caught in the SuspendThread()
3808           // infinite loop below which closes that race. A small timing
3809           // window remains before the process_exiting flag is set, but it
3810           // is only exposed when we are out of handles.
3811         } else {
3812           ++handle_count;
3813           registered = true;
3814 
3815           // The current exiting thread has stored its handle in the array, and now
3816           // should leave the critical section before calling _endthreadex().
3817         }
3818 
3819       } else if (what != EPT_THREAD && handle_count > 0) {
3820         jlong start_time, finish_time, timeout_left;
3821         // Before ending the process, make sure all the threads that had called
3822         // _endthreadex() completed.
3823 
3824         // Set the priority level of the current thread to the same value as
3825         // the priority level of exiting threads.
3826         // This is to ensure it will be given a fair chance to execute if
3827         // the timeout expires.
3828         hthr = GetCurrentThread();
3829         SetThreadPriority(hthr, THREAD_PRIORITY_ABOVE_NORMAL);
3830         start_time = os::javaTimeNanos();
3831         finish_time = start_time + ((jlong)EXIT_TIMEOUT * 1000000L);
3832         for (i = 0; ; ) {
3833           int portion_count = handle_count - i;
3834           if (portion_count > MAXIMUM_WAIT_OBJECTS) {
3835             portion_count = MAXIMUM_WAIT_OBJECTS;
3836           }
3837           for (j = 0; j < portion_count; ++j) {
3838             SetThreadPriority(handles[i + j], THREAD_PRIORITY_ABOVE_NORMAL);
3839           }
3840           timeout_left = (finish_time - start_time) / 1000000L;
3841           if (timeout_left < 0) {
3842             timeout_left = 0;
3843           }
3844           res = WaitForMultipleObjects(portion_count, handles + i, TRUE, timeout_left);
3845           if (res == WAIT_FAILED || res == WAIT_TIMEOUT) {
3846             warning("WaitForMultipleObjects %s (%u) in %s: %d\n",
3847                     (res == WAIT_FAILED ? "failed" : "timed out"),
3848                     GetLastError(), __FILE__, __LINE__);
3849             // Reset portion_count so we close the remaining
3850             // handles due to this error.
3851             portion_count = handle_count - i;
3852           }
3853           for (j = 0; j < portion_count; ++j) {
3854             CloseHandle(handles[i + j]);
3855           }
3856           if ((i += portion_count) >= handle_count) {
3857             break;
3858           }
3859           start_time = os::javaTimeNanos();
3860         }
3861         handle_count = 0;
3862       }
3863 
3864       LeaveCriticalSection(&crit_sect);
3865     }
3866 
3867     if (!registered &&
3868         OrderAccess::load_acquire(&process_exiting) != 0 &&
3869         process_exiting != GetCurrentThreadId()) {
3870       // Some other thread is about to call exit(), so we don't let
3871       // the current unregistered thread proceed to exit() or _endthreadex()
3872       while (true) {
3873         SuspendThread(GetCurrentThread());
3874         // Avoid busy-wait loop, if SuspendThread() failed.
3875         Sleep(EXIT_TIMEOUT);
3876       }
3877     }
3878   }
3879 
3880   // We are here if either
3881   // - there's no 'race at exit' bug on this OS release;
3882   // - initialization of the critical section failed (unlikely);
3883   // - the current thread has registered itself and left the critical section;
3884   // - the process-exiting thread has raised the flag and left the critical section.
3885   if (what == EPT_THREAD) {
3886     _endthreadex((unsigned)exit_code);
3887   } else if (what == EPT_PROCESS) {
3888     ::exit(exit_code);
3889   } else {
3890     _exit(exit_code);
3891   }
3892 
3893   // Should not reach here
3894   return exit_code;
3895 }
3896 
3897 #undef EXIT_TIMEOUT
3898 
3899 void os::win32::setmode_streams() {
3900   _setmode(_fileno(stdin), _O_BINARY);
3901   _setmode(_fileno(stdout), _O_BINARY);
3902   _setmode(_fileno(stderr), _O_BINARY);
3903 }
3904 
3905 
3906 bool os::is_debugger_attached() {
3907   return IsDebuggerPresent() ? true : false;
3908 }
3909 
3910 
3911 void os::wait_for_keypress_at_exit(void) {
3912   if (PauseAtExit) {
3913     fprintf(stderr, "Press any key to continue...\n");
3914     fgetc(stdin);
3915   }
3916 }
3917 
3918 
3919 bool os::message_box(const char* title, const char* message) {
3920   int result = MessageBox(NULL, message, title,
3921                           MB_YESNO | MB_ICONERROR | MB_SYSTEMMODAL | MB_DEFAULT_DESKTOP_ONLY);
3922   return result == IDYES;
3923 }
3924 
3925 #ifndef PRODUCT
3926 #ifndef _WIN64
3927 // Helpers to check whether NX protection is enabled
3928 int nx_exception_filter(_EXCEPTION_POINTERS *pex) {
3929   if (pex->ExceptionRecord->ExceptionCode == EXCEPTION_ACCESS_VIOLATION &&
3930       pex->ExceptionRecord->NumberParameters > 0 &&
3931       pex->ExceptionRecord->ExceptionInformation[0] ==
3932       EXCEPTION_INFO_EXEC_VIOLATION) {
3933     return EXCEPTION_EXECUTE_HANDLER;
3934   }
3935   return EXCEPTION_CONTINUE_SEARCH;
3936 }
3937 
3938 void nx_check_protection() {
3939   // If NX is enabled we'll get an exception calling into code on the stack
3940   char code[] = { (char)0xC3 }; // ret
3941   void *code_ptr = (void *)code;
3942   __try {
3943     __asm call code_ptr
3944   } __except(nx_exception_filter((_EXCEPTION_POINTERS*)_exception_info())) {
3945     tty->print_raw_cr("NX protection detected.");
3946   }
3947 }
3948 #endif // _WIN64
3949 #endif // PRODUCT
3950 
3951 // This is called _before_ the global arguments have been parsed
3952 void os::init(void) {
3953   _initial_pid = _getpid();
3954 
3955   init_random(1234567);
3956 
3957   win32::initialize_system_info();
3958   win32::setmode_streams();
3959   init_page_sizes((size_t) win32::vm_page_size());
3960 
3961   // This may be overridden later when argument processing is done.
3962   FLAG_SET_ERGO(bool, UseLargePagesIndividualAllocation, false);
3963 
3964   // Initialize main_process and main_thread
3965   main_process = GetCurrentProcess();  // Remember main_process is a pseudo handle
3966   if (!DuplicateHandle(main_process, GetCurrentThread(), main_process,
3967                        &main_thread, THREAD_ALL_ACCESS, false, 0)) {
3968     fatal("DuplicateHandle failed\n");
3969   }
3970   main_thread_id = (int) GetCurrentThreadId();
3971 
3972   // initialize fast thread access - only used for 32-bit
3973   win32::initialize_thread_ptr_offset();
3974 }
3975 
3976 // To install functions for atexit processing
3977 extern "C" {
3978   static void perfMemory_exit_helper() {
3979     perfMemory_exit();
3980   }
3981 }
3982 
3983 static jint initSock();
3984 
3985 // this is called _after_ the global arguments have been parsed
3986 jint os::init_2(void) {
3987   // Allocate a single page and mark it as readable for safepoint polling
3988   address polling_page = (address)VirtualAlloc(NULL, os::vm_page_size(), MEM_RESERVE, PAGE_READONLY);
3989   guarantee(polling_page != NULL, "Reserve Failed for polling page");
3990 
3991   address return_page  = (address)VirtualAlloc(polling_page, os::vm_page_size(), MEM_COMMIT, PAGE_READONLY);
3992   guarantee(return_page != NULL, "Commit Failed for polling page");
3993 
3994   os::set_polling_page(polling_page);
3995   log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(polling_page));
3996 
3997   if (!UseMembar) {
3998     address mem_serialize_page = (address)VirtualAlloc(NULL, os::vm_page_size(), MEM_RESERVE, PAGE_READWRITE);
3999     guarantee(mem_serialize_page != NULL, "Reserve Failed for memory serialize page");
4000 
4001     return_page  = (address)VirtualAlloc(mem_serialize_page, os::vm_page_size(), MEM_COMMIT, PAGE_READWRITE);
4002     guarantee(return_page != NULL, "Commit Failed for memory serialize page");
4003 
4004     os::set_memory_serialize_page(mem_serialize_page);
4005     log_info(os)("Memory Serialize Page address: " INTPTR_FORMAT, p2i(mem_serialize_page));
4006   }
4007 
4008   // Setup Windows Exceptions
4009 
4010   // for debugging float code generation bugs
4011   if (ForceFloatExceptions) {
4012 #ifndef  _WIN64
4013     static long fp_control_word = 0;
4014     __asm { fstcw fp_control_word }
4015     // see Intel PPro Manual, Vol. 2, p 7-16
4016     const long precision = 0x20;
4017     const long underflow = 0x10;
4018     const long overflow  = 0x08;
4019     const long zero_div  = 0x04;
4020     const long denorm    = 0x02;
4021     const long invalid   = 0x01;
4022     fp_control_word |= invalid;
4023     __asm { fldcw fp_control_word }
4024 #endif
4025   }
4026 
4027   // If stack_commit_size is 0, windows will reserve the default size,
4028   // but only commit a small portion of it.
4029   size_t stack_commit_size = align_up(ThreadStackSize*K, os::vm_page_size());
4030   size_t default_reserve_size = os::win32::default_stack_size();
4031   size_t actual_reserve_size = stack_commit_size;
4032   if (stack_commit_size < default_reserve_size) {
4033     // If stack_commit_size == 0, we want this too
4034     actual_reserve_size = default_reserve_size;
4035   }
4036 
4037   // Check minimum allowable stack size for thread creation and to initialize
4038   // the java system classes, including StackOverflowError - depends on page
4039   // size.  Add two 4K pages for compiler2 recursion in main thread.
4040   // Add in 4*BytesPerWord 4K pages to account for VM stack during
4041   // class initialization depending on 32 or 64 bit VM.
4042   size_t min_stack_allowed =
4043             (size_t)(JavaThread::stack_guard_zone_size() +
4044                      JavaThread::stack_shadow_zone_size() +
4045                      (4*BytesPerWord COMPILER2_PRESENT(+2)) * 4 * K);
4046 
4047   min_stack_allowed = align_up(min_stack_allowed, os::vm_page_size());
4048 
4049   if (actual_reserve_size < min_stack_allowed) {
4050     tty->print_cr("\nThe Java thread stack size specified is too small. "
4051                   "Specify at least %dk",
4052                   min_stack_allowed / K);
4053     return JNI_ERR;
4054   }
4055 
4056   JavaThread::set_stack_size_at_create(stack_commit_size);
4057 
4058   // Calculate theoretical max. size of Threads to guard gainst artifical
4059   // out-of-memory situations, where all available address-space has been
4060   // reserved by thread stacks.
4061   assert(actual_reserve_size != 0, "Must have a stack");
4062 
4063   // Calculate the thread limit when we should start doing Virtual Memory
4064   // banging. Currently when the threads will have used all but 200Mb of space.
4065   //
4066   // TODO: consider performing a similar calculation for commit size instead
4067   // as reserve size, since on a 64-bit platform we'll run into that more
4068   // often than running out of virtual memory space.  We can use the
4069   // lower value of the two calculations as the os_thread_limit.
4070   size_t max_address_space = ((size_t)1 << (BitsPerWord - 1)) - (200 * K * K);
4071   win32::_os_thread_limit = (intx)(max_address_space / actual_reserve_size);
4072 
4073   // at exit methods are called in the reverse order of their registration.
4074   // there is no limit to the number of functions registered. atexit does
4075   // not set errno.
4076 
4077   if (PerfAllowAtExitRegistration) {
4078     // only register atexit functions if PerfAllowAtExitRegistration is set.
4079     // atexit functions can be delayed until process exit time, which
4080     // can be problematic for embedded VM situations. Embedded VMs should
4081     // call DestroyJavaVM() to assure that VM resources are released.
4082 
4083     // note: perfMemory_exit_helper atexit function may be removed in
4084     // the future if the appropriate cleanup code can be added to the
4085     // VM_Exit VMOperation's doit method.
4086     if (atexit(perfMemory_exit_helper) != 0) {
4087       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
4088     }
4089   }
4090 
4091 #ifndef _WIN64
4092   // Print something if NX is enabled (win32 on AMD64)
4093   NOT_PRODUCT(if (PrintMiscellaneous && Verbose) nx_check_protection());
4094 #endif
4095 
4096   // initialize thread priority policy
4097   prio_init();
4098 
4099   if (UseNUMA && !ForceNUMA) {
4100     UseNUMA = false; // We don't fully support this yet
4101   }
4102 
4103   if (UseNUMAInterleaving) {
4104     // first check whether this Windows OS supports VirtualAllocExNuma, if not ignore this flag
4105     bool success = numa_interleaving_init();
4106     if (!success) UseNUMAInterleaving = false;
4107   }
4108 
4109   if (initSock() != JNI_OK) {
4110     return JNI_ERR;
4111   }
4112 
4113   SymbolEngine::recalc_search_path();
4114 
4115   return JNI_OK;
4116 }
4117 
4118 // Mark the polling page as unreadable
4119 void os::make_polling_page_unreadable(void) {
4120   DWORD old_status;
4121   if (!VirtualProtect((char *)_polling_page, os::vm_page_size(),
4122                       PAGE_NOACCESS, &old_status)) {
4123     fatal("Could not disable polling page");
4124   }
4125 }
4126 
4127 // Mark the polling page as readable
4128 void os::make_polling_page_readable(void) {
4129   DWORD old_status;
4130   if (!VirtualProtect((char *)_polling_page, os::vm_page_size(),
4131                       PAGE_READONLY, &old_status)) {
4132     fatal("Could not enable polling page");
4133   }
4134 }
4135 
4136 
4137 int os::stat(const char *path, struct stat *sbuf) {
4138   char pathbuf[MAX_PATH];
4139   if (strlen(path) > MAX_PATH - 1) {
4140     errno = ENAMETOOLONG;
4141     return -1;
4142   }
4143   os::native_path(strcpy(pathbuf, path));
4144   int ret = ::stat(pathbuf, sbuf);
4145   if (sbuf != NULL && UseUTCFileTimestamp) {
4146     // Fix for 6539723.  st_mtime returned from stat() is dependent on
4147     // the system timezone and so can return different values for the
4148     // same file if/when daylight savings time changes.  This adjustment
4149     // makes sure the same timestamp is returned regardless of the TZ.
4150     //
4151     // See:
4152     // http://msdn.microsoft.com/library/
4153     //   default.asp?url=/library/en-us/sysinfo/base/
4154     //   time_zone_information_str.asp
4155     // and
4156     // http://msdn.microsoft.com/library/default.asp?url=
4157     //   /library/en-us/sysinfo/base/settimezoneinformation.asp
4158     //
4159     // NOTE: there is a insidious bug here:  If the timezone is changed
4160     // after the call to stat() but before 'GetTimeZoneInformation()', then
4161     // the adjustment we do here will be wrong and we'll return the wrong
4162     // value (which will likely end up creating an invalid class data
4163     // archive).  Absent a better API for this, or some time zone locking
4164     // mechanism, we'll have to live with this risk.
4165     TIME_ZONE_INFORMATION tz;
4166     DWORD tzid = GetTimeZoneInformation(&tz);
4167     int daylightBias =
4168       (tzid == TIME_ZONE_ID_DAYLIGHT) ?  tz.DaylightBias : tz.StandardBias;
4169     sbuf->st_mtime += (tz.Bias + daylightBias) * 60;
4170   }
4171   return ret;
4172 }
4173 
4174 
4175 #define FT2INT64(ft) \
4176   ((jlong)((jlong)(ft).dwHighDateTime << 32 | (julong)(ft).dwLowDateTime))
4177 
4178 
4179 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
4180 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
4181 // of a thread.
4182 //
4183 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
4184 // the fast estimate available on the platform.
4185 
4186 // current_thread_cpu_time() is not optimized for Windows yet
4187 jlong os::current_thread_cpu_time() {
4188   // return user + sys since the cost is the same
4189   return os::thread_cpu_time(Thread::current(), true /* user+sys */);
4190 }
4191 
4192 jlong os::thread_cpu_time(Thread* thread) {
4193   // consistent with what current_thread_cpu_time() returns.
4194   return os::thread_cpu_time(thread, true /* user+sys */);
4195 }
4196 
4197 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
4198   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
4199 }
4200 
4201 jlong os::thread_cpu_time(Thread* thread, bool user_sys_cpu_time) {
4202   // This code is copy from clasic VM -> hpi::sysThreadCPUTime
4203   // If this function changes, os::is_thread_cpu_time_supported() should too
4204   FILETIME CreationTime;
4205   FILETIME ExitTime;
4206   FILETIME KernelTime;
4207   FILETIME UserTime;
4208 
4209   if (GetThreadTimes(thread->osthread()->thread_handle(), &CreationTime,
4210                       &ExitTime, &KernelTime, &UserTime) == 0) {
4211     return -1;
4212   } else if (user_sys_cpu_time) {
4213     return (FT2INT64(UserTime) + FT2INT64(KernelTime)) * 100;
4214   } else {
4215     return FT2INT64(UserTime) * 100;
4216   }
4217 }
4218 
4219 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4220   info_ptr->max_value = ALL_64_BITS;        // the max value -- all 64 bits
4221   info_ptr->may_skip_backward = false;      // GetThreadTimes returns absolute time
4222   info_ptr->may_skip_forward = false;       // GetThreadTimes returns absolute time
4223   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;   // user+system time is returned
4224 }
4225 
4226 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4227   info_ptr->max_value = ALL_64_BITS;        // the max value -- all 64 bits
4228   info_ptr->may_skip_backward = false;      // GetThreadTimes returns absolute time
4229   info_ptr->may_skip_forward = false;       // GetThreadTimes returns absolute time
4230   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;   // user+system time is returned
4231 }
4232 
4233 bool os::is_thread_cpu_time_supported() {
4234   // see os::thread_cpu_time
4235   FILETIME CreationTime;
4236   FILETIME ExitTime;
4237   FILETIME KernelTime;
4238   FILETIME UserTime;
4239 
4240   if (GetThreadTimes(GetCurrentThread(), &CreationTime, &ExitTime,
4241                       &KernelTime, &UserTime) == 0) {
4242     return false;
4243   } else {
4244     return true;
4245   }
4246 }
4247 
4248 // Windows does't provide a loadavg primitive so this is stubbed out for now.
4249 // It does have primitives (PDH API) to get CPU usage and run queue length.
4250 // "\\Processor(_Total)\\% Processor Time", "\\System\\Processor Queue Length"
4251 // If we wanted to implement loadavg on Windows, we have a few options:
4252 //
4253 // a) Query CPU usage and run queue length and "fake" an answer by
4254 //    returning the CPU usage if it's under 100%, and the run queue
4255 //    length otherwise.  It turns out that querying is pretty slow
4256 //    on Windows, on the order of 200 microseconds on a fast machine.
4257 //    Note that on the Windows the CPU usage value is the % usage
4258 //    since the last time the API was called (and the first call
4259 //    returns 100%), so we'd have to deal with that as well.
4260 //
4261 // b) Sample the "fake" answer using a sampling thread and store
4262 //    the answer in a global variable.  The call to loadavg would
4263 //    just return the value of the global, avoiding the slow query.
4264 //
4265 // c) Sample a better answer using exponential decay to smooth the
4266 //    value.  This is basically the algorithm used by UNIX kernels.
4267 //
4268 // Note that sampling thread starvation could affect both (b) and (c).
4269 int os::loadavg(double loadavg[], int nelem) {
4270   return -1;
4271 }
4272 
4273 
4274 // DontYieldALot=false by default: dutifully perform all yields as requested by JVM_Yield()
4275 bool os::dont_yield() {
4276   return DontYieldALot;
4277 }
4278 
4279 // This method is a slightly reworked copy of JDK's sysOpen
4280 // from src/windows/hpi/src/sys_api_md.c
4281 
4282 int os::open(const char *path, int oflag, int mode) {
4283   char pathbuf[MAX_PATH];
4284 
4285   if (strlen(path) > MAX_PATH - 1) {
4286     errno = ENAMETOOLONG;
4287     return -1;
4288   }
4289   os::native_path(strcpy(pathbuf, path));
4290   return ::open(pathbuf, oflag | O_BINARY | O_NOINHERIT, mode);
4291 }
4292 
4293 FILE* os::open(int fd, const char* mode) {
4294   return ::_fdopen(fd, mode);
4295 }
4296 
4297 // Is a (classpath) directory empty?
4298 bool os::dir_is_empty(const char* path) {
4299   WIN32_FIND_DATA fd;
4300   HANDLE f = FindFirstFile(path, &fd);
4301   if (f == INVALID_HANDLE_VALUE) {
4302     return true;
4303   }
4304   FindClose(f);
4305   return false;
4306 }
4307 
4308 // create binary file, rewriting existing file if required
4309 int os::create_binary_file(const char* path, bool rewrite_existing) {
4310   int oflags = _O_CREAT | _O_WRONLY | _O_BINARY;
4311   if (!rewrite_existing) {
4312     oflags |= _O_EXCL;
4313   }
4314   return ::open(path, oflags, _S_IREAD | _S_IWRITE);
4315 }
4316 
4317 // return current position of file pointer
4318 jlong os::current_file_offset(int fd) {
4319   return (jlong)::_lseeki64(fd, (__int64)0L, SEEK_CUR);
4320 }
4321 
4322 // move file pointer to the specified offset
4323 jlong os::seek_to_file_offset(int fd, jlong offset) {
4324   return (jlong)::_lseeki64(fd, (__int64)offset, SEEK_SET);
4325 }
4326 
4327 
4328 jlong os::lseek(int fd, jlong offset, int whence) {
4329   return (jlong) ::_lseeki64(fd, offset, whence);
4330 }
4331 
4332 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
4333   OVERLAPPED ov;
4334   DWORD nread;
4335   BOOL result;
4336 
4337   ZeroMemory(&ov, sizeof(ov));
4338   ov.Offset = (DWORD)offset;
4339   ov.OffsetHigh = (DWORD)(offset >> 32);
4340 
4341   HANDLE h = (HANDLE)::_get_osfhandle(fd);
4342 
4343   result = ReadFile(h, (LPVOID)buf, nBytes, &nread, &ov);
4344 
4345   return result ? nread : 0;
4346 }
4347 
4348 
4349 // This method is a slightly reworked copy of JDK's sysNativePath
4350 // from src/windows/hpi/src/path_md.c
4351 
4352 // Convert a pathname to native format.  On win32, this involves forcing all
4353 // separators to be '\\' rather than '/' (both are legal inputs, but Win95
4354 // sometimes rejects '/') and removing redundant separators.  The input path is
4355 // assumed to have been converted into the character encoding used by the local
4356 // system.  Because this might be a double-byte encoding, care is taken to
4357 // treat double-byte lead characters correctly.
4358 //
4359 // This procedure modifies the given path in place, as the result is never
4360 // longer than the original.  There is no error return; this operation always
4361 // succeeds.
4362 char * os::native_path(char *path) {
4363   char *src = path, *dst = path, *end = path;
4364   char *colon = NULL;  // If a drive specifier is found, this will
4365                        // point to the colon following the drive letter
4366 
4367   // Assumption: '/', '\\', ':', and drive letters are never lead bytes
4368   assert(((!::IsDBCSLeadByte('/')) && (!::IsDBCSLeadByte('\\'))
4369           && (!::IsDBCSLeadByte(':'))), "Illegal lead byte");
4370 
4371   // Check for leading separators
4372 #define isfilesep(c) ((c) == '/' || (c) == '\\')
4373   while (isfilesep(*src)) {
4374     src++;
4375   }
4376 
4377   if (::isalpha(*src) && !::IsDBCSLeadByte(*src) && src[1] == ':') {
4378     // Remove leading separators if followed by drive specifier.  This
4379     // hack is necessary to support file URLs containing drive
4380     // specifiers (e.g., "file://c:/path").  As a side effect,
4381     // "/c:/path" can be used as an alternative to "c:/path".
4382     *dst++ = *src++;
4383     colon = dst;
4384     *dst++ = ':';
4385     src++;
4386   } else {
4387     src = path;
4388     if (isfilesep(src[0]) && isfilesep(src[1])) {
4389       // UNC pathname: Retain first separator; leave src pointed at
4390       // second separator so that further separators will be collapsed
4391       // into the second separator.  The result will be a pathname
4392       // beginning with "\\\\" followed (most likely) by a host name.
4393       src = dst = path + 1;
4394       path[0] = '\\';     // Force first separator to '\\'
4395     }
4396   }
4397 
4398   end = dst;
4399 
4400   // Remove redundant separators from remainder of path, forcing all
4401   // separators to be '\\' rather than '/'. Also, single byte space
4402   // characters are removed from the end of the path because those
4403   // are not legal ending characters on this operating system.
4404   //
4405   while (*src != '\0') {
4406     if (isfilesep(*src)) {
4407       *dst++ = '\\'; src++;
4408       while (isfilesep(*src)) src++;
4409       if (*src == '\0') {
4410         // Check for trailing separator
4411         end = dst;
4412         if (colon == dst - 2) break;  // "z:\\"
4413         if (dst == path + 1) break;   // "\\"
4414         if (dst == path + 2 && isfilesep(path[0])) {
4415           // "\\\\" is not collapsed to "\\" because "\\\\" marks the
4416           // beginning of a UNC pathname.  Even though it is not, by
4417           // itself, a valid UNC pathname, we leave it as is in order
4418           // to be consistent with the path canonicalizer as well
4419           // as the win32 APIs, which treat this case as an invalid
4420           // UNC pathname rather than as an alias for the root
4421           // directory of the current drive.
4422           break;
4423         }
4424         end = --dst;  // Path does not denote a root directory, so
4425                       // remove trailing separator
4426         break;
4427       }
4428       end = dst;
4429     } else {
4430       if (::IsDBCSLeadByte(*src)) {  // Copy a double-byte character
4431         *dst++ = *src++;
4432         if (*src) *dst++ = *src++;
4433         end = dst;
4434       } else {  // Copy a single-byte character
4435         char c = *src++;
4436         *dst++ = c;
4437         // Space is not a legal ending character
4438         if (c != ' ') end = dst;
4439       }
4440     }
4441   }
4442 
4443   *end = '\0';
4444 
4445   // For "z:", add "." to work around a bug in the C runtime library
4446   if (colon == dst - 1) {
4447     path[2] = '.';
4448     path[3] = '\0';
4449   }
4450 
4451   return path;
4452 }
4453 
4454 // This code is a copy of JDK's sysSetLength
4455 // from src/windows/hpi/src/sys_api_md.c
4456 
4457 int os::ftruncate(int fd, jlong length) {
4458   HANDLE h = (HANDLE)::_get_osfhandle(fd);
4459   long high = (long)(length >> 32);
4460   DWORD ret;
4461 
4462   if (h == (HANDLE)(-1)) {
4463     return -1;
4464   }
4465 
4466   ret = ::SetFilePointer(h, (long)(length), &high, FILE_BEGIN);
4467   if ((ret == 0xFFFFFFFF) && (::GetLastError() != NO_ERROR)) {
4468     return -1;
4469   }
4470 
4471   if (::SetEndOfFile(h) == FALSE) {
4472     return -1;
4473   }
4474 
4475   return 0;
4476 }
4477 
4478 int os::get_fileno(FILE* fp) {
4479   return _fileno(fp);
4480 }
4481 
4482 // This code is a copy of JDK's sysSync
4483 // from src/windows/hpi/src/sys_api_md.c
4484 // except for the legacy workaround for a bug in Win 98
4485 
4486 int os::fsync(int fd) {
4487   HANDLE handle = (HANDLE)::_get_osfhandle(fd);
4488 
4489   if ((!::FlushFileBuffers(handle)) &&
4490       (GetLastError() != ERROR_ACCESS_DENIED)) {
4491     // from winerror.h
4492     return -1;
4493   }
4494   return 0;
4495 }
4496 
4497 static int nonSeekAvailable(int, long *);
4498 static int stdinAvailable(int, long *);
4499 
4500 #define S_ISCHR(mode)   (((mode) & _S_IFCHR) == _S_IFCHR)
4501 #define S_ISFIFO(mode)  (((mode) & _S_IFIFO) == _S_IFIFO)
4502 
4503 // This code is a copy of JDK's sysAvailable
4504 // from src/windows/hpi/src/sys_api_md.c
4505 
4506 int os::available(int fd, jlong *bytes) {
4507   jlong cur, end;
4508   struct _stati64 stbuf64;
4509 
4510   if (::_fstati64(fd, &stbuf64) >= 0) {
4511     int mode = stbuf64.st_mode;
4512     if (S_ISCHR(mode) || S_ISFIFO(mode)) {
4513       int ret;
4514       long lpbytes;
4515       if (fd == 0) {
4516         ret = stdinAvailable(fd, &lpbytes);
4517       } else {
4518         ret = nonSeekAvailable(fd, &lpbytes);
4519       }
4520       (*bytes) = (jlong)(lpbytes);
4521       return ret;
4522     }
4523     if ((cur = ::_lseeki64(fd, 0L, SEEK_CUR)) == -1) {
4524       return FALSE;
4525     } else if ((end = ::_lseeki64(fd, 0L, SEEK_END)) == -1) {
4526       return FALSE;
4527     } else if (::_lseeki64(fd, cur, SEEK_SET) == -1) {
4528       return FALSE;
4529     }
4530     *bytes = end - cur;
4531     return TRUE;
4532   } else {
4533     return FALSE;
4534   }
4535 }
4536 
4537 void os::flockfile(FILE* fp) {
4538   _lock_file(fp);
4539 }
4540 
4541 void os::funlockfile(FILE* fp) {
4542   _unlock_file(fp);
4543 }
4544 
4545 // This code is a copy of JDK's nonSeekAvailable
4546 // from src/windows/hpi/src/sys_api_md.c
4547 
4548 static int nonSeekAvailable(int fd, long *pbytes) {
4549   // This is used for available on non-seekable devices
4550   // (like both named and anonymous pipes, such as pipes
4551   //  connected to an exec'd process).
4552   // Standard Input is a special case.
4553   HANDLE han;
4554 
4555   if ((han = (HANDLE) ::_get_osfhandle(fd)) == (HANDLE)(-1)) {
4556     return FALSE;
4557   }
4558 
4559   if (! ::PeekNamedPipe(han, NULL, 0, NULL, (LPDWORD)pbytes, NULL)) {
4560     // PeekNamedPipe fails when at EOF.  In that case we
4561     // simply make *pbytes = 0 which is consistent with the
4562     // behavior we get on Solaris when an fd is at EOF.
4563     // The only alternative is to raise an Exception,
4564     // which isn't really warranted.
4565     //
4566     if (::GetLastError() != ERROR_BROKEN_PIPE) {
4567       return FALSE;
4568     }
4569     *pbytes = 0;
4570   }
4571   return TRUE;
4572 }
4573 
4574 #define MAX_INPUT_EVENTS 2000
4575 
4576 // This code is a copy of JDK's stdinAvailable
4577 // from src/windows/hpi/src/sys_api_md.c
4578 
4579 static int stdinAvailable(int fd, long *pbytes) {
4580   HANDLE han;
4581   DWORD numEventsRead = 0;  // Number of events read from buffer
4582   DWORD numEvents = 0;      // Number of events in buffer
4583   DWORD i = 0;              // Loop index
4584   DWORD curLength = 0;      // Position marker
4585   DWORD actualLength = 0;   // Number of bytes readable
4586   BOOL error = FALSE;       // Error holder
4587   INPUT_RECORD *lpBuffer;   // Pointer to records of input events
4588 
4589   if ((han = ::GetStdHandle(STD_INPUT_HANDLE)) == INVALID_HANDLE_VALUE) {
4590     return FALSE;
4591   }
4592 
4593   // Construct an array of input records in the console buffer
4594   error = ::GetNumberOfConsoleInputEvents(han, &numEvents);
4595   if (error == 0) {
4596     return nonSeekAvailable(fd, pbytes);
4597   }
4598 
4599   // lpBuffer must fit into 64K or else PeekConsoleInput fails
4600   if (numEvents > MAX_INPUT_EVENTS) {
4601     numEvents = MAX_INPUT_EVENTS;
4602   }
4603 
4604   lpBuffer = (INPUT_RECORD *)os::malloc(numEvents * sizeof(INPUT_RECORD), mtInternal);
4605   if (lpBuffer == NULL) {
4606     return FALSE;
4607   }
4608 
4609   error = ::PeekConsoleInput(han, lpBuffer, numEvents, &numEventsRead);
4610   if (error == 0) {
4611     os::free(lpBuffer);
4612     return FALSE;
4613   }
4614 
4615   // Examine input records for the number of bytes available
4616   for (i=0; i<numEvents; i++) {
4617     if (lpBuffer[i].EventType == KEY_EVENT) {
4618 
4619       KEY_EVENT_RECORD *keyRecord = (KEY_EVENT_RECORD *)
4620                                       &(lpBuffer[i].Event);
4621       if (keyRecord->bKeyDown == TRUE) {
4622         CHAR *keyPressed = (CHAR *) &(keyRecord->uChar);
4623         curLength++;
4624         if (*keyPressed == '\r') {
4625           actualLength = curLength;
4626         }
4627       }
4628     }
4629   }
4630 
4631   if (lpBuffer != NULL) {
4632     os::free(lpBuffer);
4633   }
4634 
4635   *pbytes = (long) actualLength;
4636   return TRUE;
4637 }
4638 
4639 // Map a block of memory.
4640 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
4641                         char *addr, size_t bytes, bool read_only,
4642                         bool allow_exec) {
4643   HANDLE hFile;
4644   char* base;
4645 
4646   hFile = CreateFile(file_name, GENERIC_READ, FILE_SHARE_READ, NULL,
4647                      OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
4648   if (hFile == NULL) {
4649     log_info(os)("CreateFile() failed: GetLastError->%ld.", GetLastError());
4650     return NULL;
4651   }
4652 
4653   if (allow_exec) {
4654     // CreateFileMapping/MapViewOfFileEx can't map executable memory
4655     // unless it comes from a PE image (which the shared archive is not.)
4656     // Even VirtualProtect refuses to give execute access to mapped memory
4657     // that was not previously executable.
4658     //
4659     // Instead, stick the executable region in anonymous memory.  Yuck.
4660     // Penalty is that ~4 pages will not be shareable - in the future
4661     // we might consider DLLizing the shared archive with a proper PE
4662     // header so that mapping executable + sharing is possible.
4663 
4664     base = (char*) VirtualAlloc(addr, bytes, MEM_COMMIT | MEM_RESERVE,
4665                                 PAGE_READWRITE);
4666     if (base == NULL) {
4667       log_info(os)("VirtualAlloc() failed: GetLastError->%ld.", GetLastError());
4668       CloseHandle(hFile);
4669       return NULL;
4670     }
4671 
4672     DWORD bytes_read;
4673     OVERLAPPED overlapped;
4674     overlapped.Offset = (DWORD)file_offset;
4675     overlapped.OffsetHigh = 0;
4676     overlapped.hEvent = NULL;
4677     // ReadFile guarantees that if the return value is true, the requested
4678     // number of bytes were read before returning.
4679     bool res = ReadFile(hFile, base, (DWORD)bytes, &bytes_read, &overlapped) != 0;
4680     if (!res) {
4681       log_info(os)("ReadFile() failed: GetLastError->%ld.", GetLastError());
4682       release_memory(base, bytes);
4683       CloseHandle(hFile);
4684       return NULL;
4685     }
4686   } else {
4687     HANDLE hMap = CreateFileMapping(hFile, NULL, PAGE_WRITECOPY, 0, 0,
4688                                     NULL /* file_name */);
4689     if (hMap == NULL) {
4690       log_info(os)("CreateFileMapping() failed: GetLastError->%ld.", GetLastError());
4691       CloseHandle(hFile);
4692       return NULL;
4693     }
4694 
4695     DWORD access = read_only ? FILE_MAP_READ : FILE_MAP_COPY;
4696     base = (char*)MapViewOfFileEx(hMap, access, 0, (DWORD)file_offset,
4697                                   (DWORD)bytes, addr);
4698     if (base == NULL) {
4699       log_info(os)("MapViewOfFileEx() failed: GetLastError->%ld.", GetLastError());
4700       CloseHandle(hMap);
4701       CloseHandle(hFile);
4702       return NULL;
4703     }
4704 
4705     if (CloseHandle(hMap) == 0) {
4706       log_info(os)("CloseHandle(hMap) failed: GetLastError->%ld.", GetLastError());
4707       CloseHandle(hFile);
4708       return base;
4709     }
4710   }
4711 
4712   if (allow_exec) {
4713     DWORD old_protect;
4714     DWORD exec_access = read_only ? PAGE_EXECUTE_READ : PAGE_EXECUTE_READWRITE;
4715     bool res = VirtualProtect(base, bytes, exec_access, &old_protect) != 0;
4716 
4717     if (!res) {
4718       log_info(os)("VirtualProtect() failed: GetLastError->%ld.", GetLastError());
4719       // Don't consider this a hard error, on IA32 even if the
4720       // VirtualProtect fails, we should still be able to execute
4721       CloseHandle(hFile);
4722       return base;
4723     }
4724   }
4725 
4726   if (CloseHandle(hFile) == 0) {
4727     log_info(os)("CloseHandle(hFile) failed: GetLastError->%ld.", GetLastError());
4728     return base;
4729   }
4730 
4731   return base;
4732 }
4733 
4734 
4735 // Remap a block of memory.
4736 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
4737                           char *addr, size_t bytes, bool read_only,
4738                           bool allow_exec) {
4739   // This OS does not allow existing memory maps to be remapped so we
4740   // have to unmap the memory before we remap it.
4741   if (!os::unmap_memory(addr, bytes)) {
4742     return NULL;
4743   }
4744 
4745   // There is a very small theoretical window between the unmap_memory()
4746   // call above and the map_memory() call below where a thread in native
4747   // code may be able to access an address that is no longer mapped.
4748 
4749   return os::map_memory(fd, file_name, file_offset, addr, bytes,
4750                         read_only, allow_exec);
4751 }
4752 
4753 
4754 // Unmap a block of memory.
4755 // Returns true=success, otherwise false.
4756 
4757 bool os::pd_unmap_memory(char* addr, size_t bytes) {
4758   MEMORY_BASIC_INFORMATION mem_info;
4759   if (VirtualQuery(addr, &mem_info, sizeof(mem_info)) == 0) {
4760     log_info(os)("VirtualQuery() failed: GetLastError->%ld.", GetLastError());
4761     return false;
4762   }
4763 
4764   // Executable memory was not mapped using CreateFileMapping/MapViewOfFileEx.
4765   // Instead, executable region was allocated using VirtualAlloc(). See
4766   // pd_map_memory() above.
4767   //
4768   // The following flags should match the 'exec_access' flages used for
4769   // VirtualProtect() in pd_map_memory().
4770   if (mem_info.Protect == PAGE_EXECUTE_READ ||
4771       mem_info.Protect == PAGE_EXECUTE_READWRITE) {
4772     return pd_release_memory(addr, bytes);
4773   }
4774 
4775   BOOL result = UnmapViewOfFile(addr);
4776   if (result == 0) {
4777     log_info(os)("UnmapViewOfFile() failed: GetLastError->%ld.", GetLastError());
4778     return false;
4779   }
4780   return true;
4781 }
4782 
4783 void os::pause() {
4784   char filename[MAX_PATH];
4785   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4786     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4787   } else {
4788     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4789   }
4790 
4791   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4792   if (fd != -1) {
4793     struct stat buf;
4794     ::close(fd);
4795     while (::stat(filename, &buf) == 0) {
4796       Sleep(100);
4797     }
4798   } else {
4799     jio_fprintf(stderr,
4800                 "Could not open pause file '%s', continuing immediately.\n", filename);
4801   }
4802 }
4803 
4804 Thread* os::ThreadCrashProtection::_protected_thread = NULL;
4805 os::ThreadCrashProtection* os::ThreadCrashProtection::_crash_protection = NULL;
4806 volatile intptr_t os::ThreadCrashProtection::_crash_mux = 0;
4807 
4808 os::ThreadCrashProtection::ThreadCrashProtection() {
4809 }
4810 
4811 // See the caveats for this class in os_windows.hpp
4812 // Protects the callback call so that raised OS EXCEPTIONS causes a jump back
4813 // into this method and returns false. If no OS EXCEPTION was raised, returns
4814 // true.
4815 // The callback is supposed to provide the method that should be protected.
4816 //
4817 bool os::ThreadCrashProtection::call(os::CrashProtectionCallback& cb) {
4818 
4819   Thread::muxAcquire(&_crash_mux, "CrashProtection");
4820 
4821   _protected_thread = Thread::current_or_null();
4822   assert(_protected_thread != NULL, "Cannot crash protect a NULL thread");
4823 
4824   bool success = true;
4825   __try {
4826     _crash_protection = this;
4827     cb.call();
4828   } __except(EXCEPTION_EXECUTE_HANDLER) {
4829     // only for protection, nothing to do
4830     success = false;
4831   }
4832   _crash_protection = NULL;
4833   _protected_thread = NULL;
4834   Thread::muxRelease(&_crash_mux);
4835   return success;
4836 }
4837 
4838 // An Event wraps a win32 "CreateEvent" kernel handle.
4839 //
4840 // We have a number of choices regarding "CreateEvent" win32 handle leakage:
4841 //
4842 // 1:  When a thread dies return the Event to the EventFreeList, clear the ParkHandle
4843 //     field, and call CloseHandle() on the win32 event handle.  Unpark() would
4844 //     need to be modified to tolerate finding a NULL (invalid) win32 event handle.
4845 //     In addition, an unpark() operation might fetch the handle field, but the
4846 //     event could recycle between the fetch and the SetEvent() operation.
4847 //     SetEvent() would either fail because the handle was invalid, or inadvertently work,
4848 //     as the win32 handle value had been recycled.  In an ideal world calling SetEvent()
4849 //     on an stale but recycled handle would be harmless, but in practice this might
4850 //     confuse other non-Sun code, so it's not a viable approach.
4851 //
4852 // 2:  Once a win32 event handle is associated with an Event, it remains associated
4853 //     with the Event.  The event handle is never closed.  This could be construed
4854 //     as handle leakage, but only up to the maximum # of threads that have been extant
4855 //     at any one time.  This shouldn't be an issue, as windows platforms typically
4856 //     permit a process to have hundreds of thousands of open handles.
4857 //
4858 // 3:  Same as (1), but periodically, at stop-the-world time, rundown the EventFreeList
4859 //     and release unused handles.
4860 //
4861 // 4:  Add a CRITICAL_SECTION to the Event to protect LD+SetEvent from LD;ST(null);CloseHandle.
4862 //     It's not clear, however, that we wouldn't be trading one type of leak for another.
4863 //
4864 // 5.  Use an RCU-like mechanism (Read-Copy Update).
4865 //     Or perhaps something similar to Maged Michael's "Hazard pointers".
4866 //
4867 // We use (2).
4868 //
4869 // TODO-FIXME:
4870 // 1.  Reconcile Doug's JSR166 j.u.c park-unpark with the objectmonitor implementation.
4871 // 2.  Consider wrapping the WaitForSingleObject(Ex) calls in SEH try/finally blocks
4872 //     to recover from (or at least detect) the dreaded Windows 841176 bug.
4873 // 3.  Collapse the interrupt_event, the JSR166 parker event, and the objectmonitor ParkEvent
4874 //     into a single win32 CreateEvent() handle.
4875 //
4876 // Assumption:
4877 //    Only one parker can exist on an event, which is why we allocate
4878 //    them per-thread. Multiple unparkers can coexist.
4879 //
4880 // _Event transitions in park()
4881 //   -1 => -1 : illegal
4882 //    1 =>  0 : pass - return immediately
4883 //    0 => -1 : block; then set _Event to 0 before returning
4884 //
4885 // _Event transitions in unpark()
4886 //    0 => 1 : just return
4887 //    1 => 1 : just return
4888 //   -1 => either 0 or 1; must signal target thread
4889 //         That is, we can safely transition _Event from -1 to either
4890 //         0 or 1.
4891 //
4892 // _Event serves as a restricted-range semaphore.
4893 //   -1 : thread is blocked, i.e. there is a waiter
4894 //    0 : neutral: thread is running or ready,
4895 //        could have been signaled after a wait started
4896 //    1 : signaled - thread is running or ready
4897 //
4898 // Another possible encoding of _Event would be with
4899 // explicit "PARKED" == 01b and "SIGNALED" == 10b bits.
4900 //
4901 
4902 int os::PlatformEvent::park(jlong Millis) {
4903   // Transitions for _Event:
4904   //   -1 => -1 : illegal
4905   //    1 =>  0 : pass - return immediately
4906   //    0 => -1 : block; then set _Event to 0 before returning
4907 
4908   guarantee(_ParkHandle != NULL , "Invariant");
4909   guarantee(Millis > 0          , "Invariant");
4910 
4911   // CONSIDER: defer assigning a CreateEvent() handle to the Event until
4912   // the initial park() operation.
4913   // Consider: use atomic decrement instead of CAS-loop
4914 
4915   int v;
4916   for (;;) {
4917     v = _Event;
4918     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4919   }
4920   guarantee((v == 0) || (v == 1), "invariant");
4921   if (v != 0) return OS_OK;
4922 
4923   // Do this the hard way by blocking ...
4924   // TODO: consider a brief spin here, gated on the success of recent
4925   // spin attempts by this thread.
4926   //
4927   // We decompose long timeouts into series of shorter timed waits.
4928   // Evidently large timo values passed in WaitForSingleObject() are problematic on some
4929   // versions of Windows.  See EventWait() for details.  This may be superstition.  Or not.
4930   // We trust the WAIT_TIMEOUT indication and don't track the elapsed wait time
4931   // with os::javaTimeNanos().  Furthermore, we assume that spurious returns from
4932   // ::WaitForSingleObject() caused by latent ::setEvent() operations will tend
4933   // to happen early in the wait interval.  Specifically, after a spurious wakeup (rv ==
4934   // WAIT_OBJECT_0 but _Event is still < 0) we don't bother to recompute Millis to compensate
4935   // for the already waited time.  This policy does not admit any new outcomes.
4936   // In the future, however, we might want to track the accumulated wait time and
4937   // adjust Millis accordingly if we encounter a spurious wakeup.
4938 
4939   const int MAXTIMEOUT = 0x10000000;
4940   DWORD rv = WAIT_TIMEOUT;
4941   while (_Event < 0 && Millis > 0) {
4942     DWORD prd = Millis;     // set prd = MAX (Millis, MAXTIMEOUT)
4943     if (Millis > MAXTIMEOUT) {
4944       prd = MAXTIMEOUT;
4945     }
4946     rv = ::WaitForSingleObject(_ParkHandle, prd);
4947     assert(rv == WAIT_OBJECT_0 || rv == WAIT_TIMEOUT, "WaitForSingleObject failed");
4948     if (rv == WAIT_TIMEOUT) {
4949       Millis -= prd;
4950     }
4951   }
4952   v = _Event;
4953   _Event = 0;
4954   // see comment at end of os::PlatformEvent::park() below:
4955   OrderAccess::fence();
4956   // If we encounter a nearly simultanous timeout expiry and unpark()
4957   // we return OS_OK indicating we awoke via unpark().
4958   // Implementor's license -- returning OS_TIMEOUT would be equally valid, however.
4959   return (v >= 0) ? OS_OK : OS_TIMEOUT;
4960 }
4961 
4962 void os::PlatformEvent::park() {
4963   // Transitions for _Event:
4964   //   -1 => -1 : illegal
4965   //    1 =>  0 : pass - return immediately
4966   //    0 => -1 : block; then set _Event to 0 before returning
4967 
4968   guarantee(_ParkHandle != NULL, "Invariant");
4969   // Invariant: Only the thread associated with the Event/PlatformEvent
4970   // may call park().
4971   // Consider: use atomic decrement instead of CAS-loop
4972   int v;
4973   for (;;) {
4974     v = _Event;
4975     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4976   }
4977   guarantee((v == 0) || (v == 1), "invariant");
4978   if (v != 0) return;
4979 
4980   // Do this the hard way by blocking ...
4981   // TODO: consider a brief spin here, gated on the success of recent
4982   // spin attempts by this thread.
4983   while (_Event < 0) {
4984     DWORD rv = ::WaitForSingleObject(_ParkHandle, INFINITE);
4985     assert(rv == WAIT_OBJECT_0, "WaitForSingleObject failed");
4986   }
4987 
4988   // Usually we'll find _Event == 0 at this point, but as
4989   // an optional optimization we clear it, just in case can
4990   // multiple unpark() operations drove _Event up to 1.
4991   _Event = 0;
4992   OrderAccess::fence();
4993   guarantee(_Event >= 0, "invariant");
4994 }
4995 
4996 void os::PlatformEvent::unpark() {
4997   guarantee(_ParkHandle != NULL, "Invariant");
4998 
4999   // Transitions for _Event:
5000   //    0 => 1 : just return
5001   //    1 => 1 : just return
5002   //   -1 => either 0 or 1; must signal target thread
5003   //         That is, we can safely transition _Event from -1 to either
5004   //         0 or 1.
5005   // See also: "Semaphores in Plan 9" by Mullender & Cox
5006   //
5007   // Note: Forcing a transition from "-1" to "1" on an unpark() means
5008   // that it will take two back-to-back park() calls for the owning
5009   // thread to block. This has the benefit of forcing a spurious return
5010   // from the first park() call after an unpark() call which will help
5011   // shake out uses of park() and unpark() without condition variables.
5012 
5013   if (Atomic::xchg(1, &_Event) >= 0) return;
5014 
5015   ::SetEvent(_ParkHandle);
5016 }
5017 
5018 
5019 // JSR166
5020 // -------------------------------------------------------
5021 
5022 // The Windows implementation of Park is very straightforward: Basic
5023 // operations on Win32 Events turn out to have the right semantics to
5024 // use them directly. We opportunistically resuse the event inherited
5025 // from Monitor.
5026 
5027 void Parker::park(bool isAbsolute, jlong time) {
5028   guarantee(_ParkEvent != NULL, "invariant");
5029   // First, demultiplex/decode time arguments
5030   if (time < 0) { // don't wait
5031     return;
5032   } else if (time == 0 && !isAbsolute) {
5033     time = INFINITE;
5034   } else if (isAbsolute) {
5035     time -= os::javaTimeMillis(); // convert to relative time
5036     if (time <= 0) {  // already elapsed
5037       return;
5038     }
5039   } else { // relative
5040     time /= 1000000;  // Must coarsen from nanos to millis
5041     if (time == 0) {  // Wait for the minimal time unit if zero
5042       time = 1;
5043     }
5044   }
5045 
5046   JavaThread* thread = JavaThread::current();
5047 
5048   // Don't wait if interrupted or already triggered
5049   if (Thread::is_interrupted(thread, false) ||
5050       WaitForSingleObject(_ParkEvent, 0) == WAIT_OBJECT_0) {
5051     ResetEvent(_ParkEvent);
5052     return;
5053   } else {
5054     ThreadBlockInVM tbivm(thread);
5055     OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
5056     thread->set_suspend_equivalent();
5057 
5058     WaitForSingleObject(_ParkEvent, time);
5059     ResetEvent(_ParkEvent);
5060 
5061     // If externally suspended while waiting, re-suspend
5062     if (thread->handle_special_suspend_equivalent_condition()) {
5063       thread->java_suspend_self();
5064     }
5065   }
5066 }
5067 
5068 void Parker::unpark() {
5069   guarantee(_ParkEvent != NULL, "invariant");
5070   SetEvent(_ParkEvent);
5071 }
5072 
5073 // Run the specified command in a separate process. Return its exit value,
5074 // or -1 on failure (e.g. can't create a new process).
5075 int os::fork_and_exec(char* cmd) {
5076   STARTUPINFO si;
5077   PROCESS_INFORMATION pi;
5078   DWORD exit_code;
5079 
5080   char * cmd_string;
5081   char * cmd_prefix = "cmd /C ";
5082   size_t len = strlen(cmd) + strlen(cmd_prefix) + 1;
5083   cmd_string = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtInternal);
5084   if (cmd_string == NULL) {
5085     return -1;
5086   }
5087   cmd_string[0] = '\0';
5088   strcat(cmd_string, cmd_prefix);
5089   strcat(cmd_string, cmd);
5090 
5091   // now replace all '\n' with '&'
5092   char * substring = cmd_string;
5093   while ((substring = strchr(substring, '\n')) != NULL) {
5094     substring[0] = '&';
5095     substring++;
5096   }
5097   memset(&si, 0, sizeof(si));
5098   si.cb = sizeof(si);
5099   memset(&pi, 0, sizeof(pi));
5100   BOOL rslt = CreateProcess(NULL,   // executable name - use command line
5101                             cmd_string,    // command line
5102                             NULL,   // process security attribute
5103                             NULL,   // thread security attribute
5104                             TRUE,   // inherits system handles
5105                             0,      // no creation flags
5106                             NULL,   // use parent's environment block
5107                             NULL,   // use parent's starting directory
5108                             &si,    // (in) startup information
5109                             &pi);   // (out) process information
5110 
5111   if (rslt) {
5112     // Wait until child process exits.
5113     WaitForSingleObject(pi.hProcess, INFINITE);
5114 
5115     GetExitCodeProcess(pi.hProcess, &exit_code);
5116 
5117     // Close process and thread handles.
5118     CloseHandle(pi.hProcess);
5119     CloseHandle(pi.hThread);
5120   } else {
5121     exit_code = -1;
5122   }
5123 
5124   FREE_C_HEAP_ARRAY(char, cmd_string);
5125   return (int)exit_code;
5126 }
5127 
5128 bool os::find(address addr, outputStream* st) {
5129   int offset = -1;
5130   bool result = false;
5131   char buf[256];
5132   if (os::dll_address_to_library_name(addr, buf, sizeof(buf), &offset)) {
5133     st->print(PTR_FORMAT " ", addr);
5134     if (strlen(buf) < sizeof(buf) - 1) {
5135       char* p = strrchr(buf, '\\');
5136       if (p) {
5137         st->print("%s", p + 1);
5138       } else {
5139         st->print("%s", buf);
5140       }
5141     } else {
5142         // The library name is probably truncated. Let's omit the library name.
5143         // See also JDK-8147512.
5144     }
5145     if (os::dll_address_to_function_name(addr, buf, sizeof(buf), &offset)) {
5146       st->print("::%s + 0x%x", buf, offset);
5147     }
5148     st->cr();
5149     result = true;
5150   }
5151   return result;
5152 }
5153 
5154 LONG WINAPI os::win32::serialize_fault_filter(struct _EXCEPTION_POINTERS* e) {
5155   DWORD exception_code = e->ExceptionRecord->ExceptionCode;
5156 
5157   if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
5158     JavaThread* thread = JavaThread::current();
5159     PEXCEPTION_RECORD exceptionRecord = e->ExceptionRecord;
5160     address addr = (address) exceptionRecord->ExceptionInformation[1];
5161 
5162     if (os::is_memory_serialize_page(thread, addr)) {
5163       return EXCEPTION_CONTINUE_EXECUTION;
5164     }
5165   }
5166 
5167   return EXCEPTION_CONTINUE_SEARCH;
5168 }
5169 
5170 // We don't build a headless jre for Windows
5171 bool os::is_headless_jre() { return false; }
5172 
5173 static jint initSock() {
5174   WSADATA wsadata;
5175 
5176   if (WSAStartup(MAKEWORD(2,2), &wsadata) != 0) {
5177     jio_fprintf(stderr, "Could not initialize Winsock (error: %d)\n",
5178                 ::GetLastError());
5179     return JNI_ERR;
5180   }
5181   return JNI_OK;
5182 }
5183 
5184 struct hostent* os::get_host_by_name(char* name) {
5185   return (struct hostent*)gethostbyname(name);
5186 }
5187 
5188 int os::socket_close(int fd) {
5189   return ::closesocket(fd);
5190 }
5191 
5192 int os::socket(int domain, int type, int protocol) {
5193   return ::socket(domain, type, protocol);
5194 }
5195 
5196 int os::connect(int fd, struct sockaddr* him, socklen_t len) {
5197   return ::connect(fd, him, len);
5198 }
5199 
5200 int os::recv(int fd, char* buf, size_t nBytes, uint flags) {
5201   return ::recv(fd, buf, (int)nBytes, flags);
5202 }
5203 
5204 int os::send(int fd, char* buf, size_t nBytes, uint flags) {
5205   return ::send(fd, buf, (int)nBytes, flags);
5206 }
5207 
5208 int os::raw_send(int fd, char* buf, size_t nBytes, uint flags) {
5209   return ::send(fd, buf, (int)nBytes, flags);
5210 }
5211 
5212 // WINDOWS CONTEXT Flags for THREAD_SAMPLING
5213 #if defined(IA32)
5214   #define sampling_context_flags (CONTEXT_FULL | CONTEXT_FLOATING_POINT | CONTEXT_EXTENDED_REGISTERS)
5215 #elif defined (AMD64)
5216   #define sampling_context_flags (CONTEXT_FULL | CONTEXT_FLOATING_POINT)
5217 #endif
5218 
5219 // returns true if thread could be suspended,
5220 // false otherwise
5221 static bool do_suspend(HANDLE* h) {
5222   if (h != NULL) {
5223     if (SuspendThread(*h) != ~0) {
5224       return true;
5225     }
5226   }
5227   return false;
5228 }
5229 
5230 // resume the thread
5231 // calling resume on an active thread is a no-op
5232 static void do_resume(HANDLE* h) {
5233   if (h != NULL) {
5234     ResumeThread(*h);
5235   }
5236 }
5237 
5238 // retrieve a suspend/resume context capable handle
5239 // from the tid. Caller validates handle return value.
5240 void get_thread_handle_for_extended_context(HANDLE* h,
5241                                             OSThread::thread_id_t tid) {
5242   if (h != NULL) {
5243     *h = OpenThread(THREAD_SUSPEND_RESUME | THREAD_GET_CONTEXT | THREAD_QUERY_INFORMATION, FALSE, tid);
5244   }
5245 }
5246 
5247 // Thread sampling implementation
5248 //
5249 void os::SuspendedThreadTask::internal_do_task() {
5250   CONTEXT    ctxt;
5251   HANDLE     h = NULL;
5252 
5253   // get context capable handle for thread
5254   get_thread_handle_for_extended_context(&h, _thread->osthread()->thread_id());
5255 
5256   // sanity
5257   if (h == NULL || h == INVALID_HANDLE_VALUE) {
5258     return;
5259   }
5260 
5261   // suspend the thread
5262   if (do_suspend(&h)) {
5263     ctxt.ContextFlags = sampling_context_flags;
5264     // get thread context
5265     GetThreadContext(h, &ctxt);
5266     SuspendedThreadTaskContext context(_thread, &ctxt);
5267     // pass context to Thread Sampling impl
5268     do_task(context);
5269     // resume thread
5270     do_resume(&h);
5271   }
5272 
5273   // close handle
5274   CloseHandle(h);
5275 }
5276 
5277 bool os::start_debugging(char *buf, int buflen) {
5278   int len = (int)strlen(buf);
5279   char *p = &buf[len];
5280 
5281   jio_snprintf(p, buflen-len,
5282              "\n\n"
5283              "Do you want to debug the problem?\n\n"
5284              "To debug, attach Visual Studio to process %d; then switch to thread 0x%x\n"
5285              "Select 'Yes' to launch Visual Studio automatically (PATH must include msdev)\n"
5286              "Otherwise, select 'No' to abort...",
5287              os::current_process_id(), os::current_thread_id());
5288 
5289   bool yes = os::message_box("Unexpected Error", buf);
5290 
5291   if (yes) {
5292     // os::breakpoint() calls DebugBreak(), which causes a breakpoint
5293     // exception. If VM is running inside a debugger, the debugger will
5294     // catch the exception. Otherwise, the breakpoint exception will reach
5295     // the default windows exception handler, which can spawn a debugger and
5296     // automatically attach to the dying VM.
5297     os::breakpoint();
5298     yes = false;
5299   }
5300   return yes;
5301 }
5302 
5303 void* os::get_default_process_handle() {
5304   return (void*)GetModuleHandle(NULL);
5305 }
5306 
5307 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
5308 // which is used to find statically linked in agents.
5309 // Additionally for windows, takes into account __stdcall names.
5310 // Parameters:
5311 //            sym_name: Symbol in library we are looking for
5312 //            lib_name: Name of library to look in, NULL for shared libs.
5313 //            is_absolute_path == true if lib_name is absolute path to agent
5314 //                                     such as "C:/a/b/L.dll"
5315 //            == false if only the base name of the library is passed in
5316 //               such as "L"
5317 char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
5318                                     bool is_absolute_path) {
5319   char *agent_entry_name;
5320   size_t len;
5321   size_t name_len;
5322   size_t prefix_len = strlen(JNI_LIB_PREFIX);
5323   size_t suffix_len = strlen(JNI_LIB_SUFFIX);
5324   const char *start;
5325 
5326   if (lib_name != NULL) {
5327     len = name_len = strlen(lib_name);
5328     if (is_absolute_path) {
5329       // Need to strip path, prefix and suffix
5330       if ((start = strrchr(lib_name, *os::file_separator())) != NULL) {
5331         lib_name = ++start;
5332       } else {
5333         // Need to check for drive prefix
5334         if ((start = strchr(lib_name, ':')) != NULL) {
5335           lib_name = ++start;
5336         }
5337       }
5338       if (len <= (prefix_len + suffix_len)) {
5339         return NULL;
5340       }
5341       lib_name += prefix_len;
5342       name_len = strlen(lib_name) - suffix_len;
5343     }
5344   }
5345   len = (lib_name != NULL ? name_len : 0) + strlen(sym_name) + 2;
5346   agent_entry_name = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len, mtThread);
5347   if (agent_entry_name == NULL) {
5348     return NULL;
5349   }
5350   if (lib_name != NULL) {
5351     const char *p = strrchr(sym_name, '@');
5352     if (p != NULL && p != sym_name) {
5353       // sym_name == _Agent_OnLoad@XX
5354       strncpy(agent_entry_name, sym_name, (p - sym_name));
5355       agent_entry_name[(p-sym_name)] = '\0';
5356       // agent_entry_name == _Agent_OnLoad
5357       strcat(agent_entry_name, "_");
5358       strncat(agent_entry_name, lib_name, name_len);
5359       strcat(agent_entry_name, p);
5360       // agent_entry_name == _Agent_OnLoad_lib_name@XX
5361     } else {
5362       strcpy(agent_entry_name, sym_name);
5363       strcat(agent_entry_name, "_");
5364       strncat(agent_entry_name, lib_name, name_len);
5365     }
5366   } else {
5367     strcpy(agent_entry_name, sym_name);
5368   }
5369   return agent_entry_name;
5370 }
5371 
5372 #ifndef PRODUCT
5373 
5374 // test the code path in reserve_memory_special() that tries to allocate memory in a single
5375 // contiguous memory block at a particular address.
5376 // The test first tries to find a good approximate address to allocate at by using the same
5377 // method to allocate some memory at any address. The test then tries to allocate memory in
5378 // the vicinity (not directly after it to avoid possible by-chance use of that location)
5379 // This is of course only some dodgy assumption, there is no guarantee that the vicinity of
5380 // the previously allocated memory is available for allocation. The only actual failure
5381 // that is reported is when the test tries to allocate at a particular location but gets a
5382 // different valid one. A NULL return value at this point is not considered an error but may
5383 // be legitimate.
5384 // If -XX:+VerboseInternalVMTests is enabled, print some explanatory messages.
5385 void TestReserveMemorySpecial_test() {
5386   if (!UseLargePages) {
5387     if (VerboseInternalVMTests) {
5388       tty->print("Skipping test because large pages are disabled");
5389     }
5390     return;
5391   }
5392   // save current value of globals
5393   bool old_use_large_pages_individual_allocation = UseLargePagesIndividualAllocation;
5394   bool old_use_numa_interleaving = UseNUMAInterleaving;
5395 
5396   // set globals to make sure we hit the correct code path
5397   UseLargePagesIndividualAllocation = UseNUMAInterleaving = false;
5398 
5399   // do an allocation at an address selected by the OS to get a good one.
5400   const size_t large_allocation_size = os::large_page_size() * 4;
5401   char* result = os::reserve_memory_special(large_allocation_size, os::large_page_size(), NULL, false);
5402   if (result == NULL) {
5403     if (VerboseInternalVMTests) {
5404       tty->print("Failed to allocate control block with size " SIZE_FORMAT ". Skipping remainder of test.",
5405                           large_allocation_size);
5406     }
5407   } else {
5408     os::release_memory_special(result, large_allocation_size);
5409 
5410     // allocate another page within the recently allocated memory area which seems to be a good location. At least
5411     // we managed to get it once.
5412     const size_t expected_allocation_size = os::large_page_size();
5413     char* expected_location = result + os::large_page_size();
5414     char* actual_location = os::reserve_memory_special(expected_allocation_size, os::large_page_size(), expected_location, false);
5415     if (actual_location == NULL) {
5416       if (VerboseInternalVMTests) {
5417         tty->print("Failed to allocate any memory at " PTR_FORMAT " size " SIZE_FORMAT ". Skipping remainder of test.",
5418                             expected_location, large_allocation_size);
5419       }
5420     } else {
5421       // release memory
5422       os::release_memory_special(actual_location, expected_allocation_size);
5423       // only now check, after releasing any memory to avoid any leaks.
5424       assert(actual_location == expected_location,
5425              "Failed to allocate memory at requested location " PTR_FORMAT " of size " SIZE_FORMAT ", is " PTR_FORMAT " instead",
5426              expected_location, expected_allocation_size, actual_location);
5427     }
5428   }
5429 
5430   // restore globals
5431   UseLargePagesIndividualAllocation = old_use_large_pages_individual_allocation;
5432   UseNUMAInterleaving = old_use_numa_interleaving;
5433 }
5434 #endif // PRODUCT
5435 
5436 /*
5437   All the defined signal names for Windows.
5438 
5439   NOTE that not all of these names are accepted by FindSignal!
5440 
5441   For various reasons some of these may be rejected at runtime.
5442 
5443   Here are the names currently accepted by a user of sun.misc.Signal with
5444   1.4.1 (ignoring potential interaction with use of chaining, etc):
5445 
5446      (LIST TBD)
5447 
5448 */
5449 int os::get_signal_number(const char* name) {
5450   static const struct {
5451     char* name;
5452     int   number;
5453   } siglabels [] =
5454     // derived from version 6.0 VC98/include/signal.h
5455   {"ABRT",      SIGABRT,        // abnormal termination triggered by abort cl
5456   "FPE",        SIGFPE,         // floating point exception
5457   "SEGV",       SIGSEGV,        // segment violation
5458   "INT",        SIGINT,         // interrupt
5459   "TERM",       SIGTERM,        // software term signal from kill
5460   "BREAK",      SIGBREAK,       // Ctrl-Break sequence
5461   "ILL",        SIGILL};        // illegal instruction
5462   for (unsigned i = 0; i < ARRAY_SIZE(siglabels); ++i) {
5463     if (strcmp(name, siglabels[i].name) == 0) {
5464       return siglabels[i].number;
5465     }
5466   }
5467   return -1;
5468 }
5469 
5470 // Fast current thread access
5471 
5472 int os::win32::_thread_ptr_offset = 0;
5473 
5474 static void call_wrapper_dummy() {}
5475 
5476 // We need to call the os_exception_wrapper once so that it sets
5477 // up the offset from FS of the thread pointer.
5478 void os::win32::initialize_thread_ptr_offset() {
5479   os::os_exception_wrapper((java_call_t)call_wrapper_dummy,
5480                            NULL, NULL, NULL, NULL);
5481 }