base/threading/platform_thread_win.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/threading/platform_thread.h"
   6
   7 #include "base/debug/alias.h"
   8 #include "base/debug/profiler.h"
   9 #include "base/logging.h"
  10 #include "base/threading/thread_local.h"
  11 #include "base/threading/thread_restrictions.h"
  12 #include "base/tracked_objects.h"
  13
  14 #include "base/win/windows_version.h"
  15
  16 namespace base {
  17
  18 namespace {
  19
  20 static ThreadLocalPointer<char> current_thread_name;
  21
  22 // The information on how to set the thread name comes from
  23 // a MSDN article: http://msdn2.microsoft.com/en-us/library/xcb2z8hs.aspx
  24 const DWORD kVCThreadNameException = 0x406D1388;
  25
  26 typedef struct tagTHREADNAME_INFO {
  27   DWORD dwType;  // Must be 0x1000.
  28   LPCSTR szName;  // Pointer to name (in user addr space).
  29   DWORD dwThreadID;  // Thread ID (-1=caller thread).
  30   DWORD dwFlags;  // Reserved for future use, must be zero.
  31 } THREADNAME_INFO;
  32
  33 // This function has try handling, so it is separated out of its caller.
  34 void SetNameInternal(PlatformThreadId thread_id, const char* name) {
  35   THREADNAME_INFO info;
  36   info.dwType = 0x1000;
  37   info.szName = name;
  38   info.dwThreadID = thread_id;
  39   info.dwFlags = 0;
  40
  41   __try {
  42     RaiseException(kVCThreadNameException, 0, sizeof(info)/sizeof(DWORD),
  43                    reinterpret_cast<DWORD_PTR*>(&info));
  44   } __except(EXCEPTION_CONTINUE_EXECUTION) {
  45   }
  46 }
  47
  48 struct ThreadParams {
  49   PlatformThread::Delegate* delegate;
  50   bool joinable;
  51 };
  52
  53 DWORD __stdcall ThreadFunc(void* params) {
  54   ThreadParams* thread_params = static_cast<ThreadParams*>(params);
  55   PlatformThread::Delegate* delegate = thread_params->delegate;
  56   if (!thread_params->joinable)
  57     base::ThreadRestrictions::SetSingletonAllowed(false);
  58   delete thread_params;
  59   delegate->ThreadMain();
  60   return NULL;
  61 }
  62
  63 // CreateThreadInternal() matches PlatformThread::Create(), except that
  64 // |out_thread_handle| may be NULL, in which case a non-joinable thread is
  65 // created.
  66 bool CreateThreadInternal(size_t stack_size,
  67                           PlatformThread::Delegate* delegate,
  68                           PlatformThreadHandle* out_thread_handle) {
  69   PlatformThreadHandle thread_handle;
  70   unsigned int flags = 0;
  71   if (stack_size > 0 && base::win::GetVersion() >= base::win::VERSION_XP) {
  72     flags = STACK_SIZE_PARAM_IS_A_RESERVATION;
  73   } else {
  74     stack_size = 0;
  75   }
  76
  77   ThreadParams* params = new ThreadParams;
  78   params->delegate = delegate;
  79   params->joinable = out_thread_handle != NULL;
  80
  81   // Using CreateThread here vs _beginthreadex makes thread creation a bit
  82   // faster and doesn't require the loader lock to be available.  Our code will
  83   // have to work running on CreateThread() threads anyway, since we run code
  84   // on the Windows thread pool, etc.  For some background on the difference:
  85   //   http://www.microsoft.com/msj/1099/win32/win321099.aspx
  86   thread_handle = CreateThread(
  87       NULL, stack_size, ThreadFunc, params, flags, NULL);
  88   if (!thread_handle) {
  89     delete params;
  90     return false;
  91   }
  92
  93   if (out_thread_handle)
  94     *out_thread_handle = thread_handle;
  95   else
  96     CloseHandle(thread_handle);
  97   return true;
  98 }
  99
 100 }  // namespace
 101
 102 // static
 103 PlatformThreadId PlatformThread::CurrentId() {
 104   return GetCurrentThreadId();
 105 }
 106
 107 // static
 108 void PlatformThread::YieldCurrentThread() {
 109   ::Sleep(0);
 110 }
 111
 112 // static
 113 void PlatformThread::Sleep(TimeDelta duration) {
 114   ::Sleep(duration.InMillisecondsRoundedUp());
 115 }
 116
 117 // static
 118 void PlatformThread::SetName(const char* name) {
 119   current_thread_name.Set(const_cast<char*>(name));
 120
 121   // On Windows only, we don't need to tell the profiler about the "BrokerEvent"
 122   // thread, as it exists only in the chrome.exe image, and never spawns or runs
 123   // tasks (items which could be profiled).  This test avoids the notification,
 124   // which would also (as a side effect) initialize the profiler in this unused
 125   // context, including setting up thread local storage, etc.  The performance
 126   // impact is not terrible, but there is no reason to do initialize it.
 127   if (0 != strcmp(name, "BrokerEvent"))
 128     tracked_objects::ThreadData::InitializeThreadContext(name);
 129
 130   // The debugger needs to be around to catch the name in the exception.  If
 131   // there isn't a debugger, we are just needlessly throwing an exception.
 132   // If this image file is instrumented, we raise the exception anyway
 133   // to provide the profiler with human-readable thread names.
 134   if (!::IsDebuggerPresent() && !base::debug::IsBinaryInstrumented())
 135     return;
 136
 137   SetNameInternal(CurrentId(), name);
 138 }
 139
 140 // static
 141 const char* PlatformThread::GetName() {
 142   return current_thread_name.Get();
 143 }
 144
 145 // static
 146 bool PlatformThread::Create(size_t stack_size, Delegate* delegate,
 147                             PlatformThreadHandle* thread_handle) {
 148   DCHECK(thread_handle);
 149   return CreateThreadInternal(stack_size, delegate, thread_handle);
 150 }
 151
 152 // static
 153 bool PlatformThread::CreateWithPriority(size_t stack_size, Delegate* delegate,
 154                                         PlatformThreadHandle* thread_handle,
 155                                         ThreadPriority priority) {
 156   bool result = Create(stack_size, delegate, thread_handle);
 157   if (result)
 158     SetThreadPriority(*thread_handle, priority);
 159   return result;
 160 }
 161
 162 // static
 163 bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
 164   return CreateThreadInternal(stack_size, delegate, NULL);
 165 }
 166
 167 // static
 168 void PlatformThread::Join(PlatformThreadHandle thread_handle) {
 169   DCHECK(thread_handle);
 170   // TODO(willchan): Enable this check once I can get it to work for Windows
 171   // shutdown.
 172   // Joining another thread may block the current thread for a long time, since
 173   // the thread referred to by |thread_handle| may still be running long-lived /
 174   // blocking tasks.
 175 #if 0
 176   base::ThreadRestrictions::AssertIOAllowed();
 177 #endif
 178
 179   // Wait for the thread to exit.  It should already have terminated but make
 180   // sure this assumption is valid.
 181   DWORD result = WaitForSingleObject(thread_handle, INFINITE);
 182   if (result != WAIT_OBJECT_0) {
 183     // Debug info for bug 127931.
 184     DWORD error = GetLastError();
 185     debug::Alias(&error);
 186     debug::Alias(&result);
 187     debug::Alias(&thread_handle);
 188     CHECK(false);
 189   }
 190
 191   CloseHandle(thread_handle);
 192 }
 193
 194 // static
 195 void PlatformThread::SetThreadPriority(PlatformThreadHandle handle,
 196                                        ThreadPriority priority) {
 197   switch (priority) {
 198     case kThreadPriority_Normal:
 199       ::SetThreadPriority(handle, THREAD_PRIORITY_NORMAL);
 200       break;
 201     case kThreadPriority_RealtimeAudio:
 202       ::SetThreadPriority(handle, THREAD_PRIORITY_TIME_CRITICAL);
 203       break;
 204   }
 205 }
 206
 207 }  // namespace base