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_id_name_manager.h"
  11 #include "base/threading/thread_restrictions.h"
  12 #include "base/tracked_objects.h"
  13 #include "base/win/scoped_handle.h"
  14 #include "base/win/windows_version.h"
  15
  16 namespace base {
  17
  18 namespace {
  19
  20 // The information on how to set the thread name comes from
  21 // a MSDN article: http://msdn2.microsoft.com/en-us/library/xcb2z8hs.aspx
  22 const DWORD kVCThreadNameException = 0x406D1388;
  23
  24 typedef struct tagTHREADNAME_INFO {
  25   DWORD dwType;  // Must be 0x1000.
  26   LPCSTR szName;  // Pointer to name (in user addr space).
  27   DWORD dwThreadID;  // Thread ID (-1=caller thread).
  28   DWORD dwFlags;  // Reserved for future use, must be zero.
  29 } THREADNAME_INFO;
  30
  31 // This function has try handling, so it is separated out of its caller.
  32 void SetNameInternal(PlatformThreadId thread_id, const char* name) {
  33   THREADNAME_INFO info;
  34   info.dwType = 0x1000;
  35   info.szName = name;
  36   info.dwThreadID = thread_id;
  37   info.dwFlags = 0;
  38
  39   __try {
  40     RaiseException(kVCThreadNameException, 0, sizeof(info)/sizeof(DWORD),
  41                    reinterpret_cast<DWORD_PTR*>(&info));
  42   } __except(EXCEPTION_CONTINUE_EXECUTION) {
  43   }
  44 }
  45
  46 struct ThreadParams {
  47   PlatformThread::Delegate* delegate;
  48   bool joinable;
  49   ThreadPriority priority;
  50 };
  51
  52 DWORD __stdcall ThreadFunc(void* params) {
  53   ThreadParams* thread_params = static_cast<ThreadParams*>(params);
  54   PlatformThread::Delegate* delegate = thread_params->delegate;
  55   if (!thread_params->joinable)
  56     base::ThreadRestrictions::SetSingletonAllowed(false);
  57
  58   if (thread_params->priority != ThreadPriority::NORMAL) {
  59     PlatformThread::SetThreadPriority(
  60         PlatformThread::CurrentHandle(), thread_params->priority);
  61   }
  62
  63   // Retrieve a copy of the thread handle to use as the key in the
  64   // thread name mapping.
  65   PlatformThreadHandle::Handle platform_handle;
  66   BOOL did_dup = DuplicateHandle(GetCurrentProcess(),
  67                                 GetCurrentThread(),
  68                                 GetCurrentProcess(),
  69                                 &platform_handle,
  70                                 0,
  71                                 FALSE,
  72                                 DUPLICATE_SAME_ACCESS);
  73
  74   win::ScopedHandle scoped_platform_handle;
  75
  76   if (did_dup) {
  77     scoped_platform_handle.Set(platform_handle);
  78     ThreadIdNameManager::GetInstance()->RegisterThread(
  79         scoped_platform_handle.Get(),
  80         PlatformThread::CurrentId());
  81   }
  82
  83   delete thread_params;
  84   delegate->ThreadMain();
  85
  86   if (did_dup) {
  87     ThreadIdNameManager::GetInstance()->RemoveName(
  88         scoped_platform_handle.Get(),
  89         PlatformThread::CurrentId());
  90   }
  91
  92   return NULL;
  93 }
  94
  95 // CreateThreadInternal() matches PlatformThread::CreateWithPriority(), except
  96 // that |out_thread_handle| may be NULL, in which case a non-joinable thread is
  97 // created.
  98 bool CreateThreadInternal(size_t stack_size,
  99                           PlatformThread::Delegate* delegate,
 100                           PlatformThreadHandle* out_thread_handle,
 101                           ThreadPriority priority) {
 102   unsigned int flags = 0;
 103   if (stack_size > 0 && base::win::GetVersion() >= base::win::VERSION_XP) {
 104     flags = STACK_SIZE_PARAM_IS_A_RESERVATION;
 105   } else {
 106     stack_size = 0;
 107   }
 108
 109   ThreadParams* params = new ThreadParams;
 110   params->delegate = delegate;
 111   params->joinable = out_thread_handle != NULL;
 112   params->priority = priority;
 113
 114   // Using CreateThread here vs _beginthreadex makes thread creation a bit
 115   // faster and doesn't require the loader lock to be available.  Our code will
 116   // have to work running on CreateThread() threads anyway, since we run code
 117   // on the Windows thread pool, etc.  For some background on the difference:
 118   //   http://www.microsoft.com/msj/1099/win32/win321099.aspx
 119   PlatformThreadId thread_id;
 120   void* thread_handle = CreateThread(
 121       NULL, stack_size, ThreadFunc, params, flags, &thread_id);
 122   if (!thread_handle) {
 123     delete params;
 124     return false;
 125   }
 126
 127   if (out_thread_handle)
 128     *out_thread_handle = PlatformThreadHandle(thread_handle, thread_id);
 129   else
 130     CloseHandle(thread_handle);
 131   return true;
 132 }
 133
 134 }  // namespace
 135
 136 // static
 137 PlatformThreadId PlatformThread::CurrentId() {
 138   return ::GetCurrentThreadId();
 139 }
 140
 141 // static
 142 PlatformThreadRef PlatformThread::CurrentRef() {
 143   return PlatformThreadRef(::GetCurrentThreadId());
 144 }
 145
 146 // static
 147 PlatformThreadHandle PlatformThread::CurrentHandle() {
 148   return PlatformThreadHandle(::GetCurrentThread());
 149 }
 150
 151 // static
 152 void PlatformThread::YieldCurrentThread() {
 153   ::Sleep(0);
 154 }
 155
 156 // static
 157 void PlatformThread::Sleep(TimeDelta duration) {
 158   // When measured with a high resolution clock, Sleep() sometimes returns much
 159   // too early. We may need to call it repeatedly to get the desired duration.
 160   TimeTicks end = TimeTicks::Now() + duration;
 161   for (TimeTicks now = TimeTicks::Now(); now < end; now = TimeTicks::Now())
 162     ::Sleep(static_cast<DWORD>((end - now).InMillisecondsRoundedUp()));
 163 }
 164
 165 // static
 166 void PlatformThread::SetName(const std::string& name) {
 167   ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
 168
 169   // On Windows only, we don't need to tell the profiler about the "BrokerEvent"
 170   // thread, as it exists only in the chrome.exe image, and never spawns or runs
 171   // tasks (items which could be profiled).  This test avoids the notification,
 172   // which would also (as a side effect) initialize the profiler in this unused
 173   // context, including setting up thread local storage, etc.  The performance
 174   // impact is not terrible, but there is no reason to do initialize it.
 175   if (name != "BrokerEvent")
 176     tracked_objects::ThreadData::InitializeThreadContext(name);
 177
 178   // The debugger needs to be around to catch the name in the exception.  If
 179   // there isn't a debugger, we are just needlessly throwing an exception.
 180   // If this image file is instrumented, we raise the exception anyway
 181   // to provide the profiler with human-readable thread names.
 182   if (!::IsDebuggerPresent() && !base::debug::IsBinaryInstrumented())
 183     return;
 184
 185   SetNameInternal(CurrentId(), name.c_str());
 186 }
 187
 188 // static
 189 const char* PlatformThread::GetName() {
 190   return ThreadIdNameManager::GetInstance()->GetName(CurrentId());
 191 }
 192
 193 // static
 194 bool PlatformThread::Create(size_t stack_size, Delegate* delegate,
 195                             PlatformThreadHandle* thread_handle) {
 196   return CreateWithPriority(
 197       stack_size, delegate, thread_handle, ThreadPriority::NORMAL);
 198 }
 199
 200 // static
 201 bool PlatformThread::CreateWithPriority(size_t stack_size, Delegate* delegate,
 202                                         PlatformThreadHandle* thread_handle,
 203                                         ThreadPriority priority) {
 204   DCHECK(thread_handle);
 205   return CreateThreadInternal(stack_size, delegate, thread_handle, priority);
 206 }
 207
 208 // static
 209 bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
 210   return CreateThreadInternal(
 211       stack_size, delegate, NULL, ThreadPriority::NORMAL);
 212 }
 213
 214 // static
 215 void PlatformThread::Join(PlatformThreadHandle thread_handle) {
 216   DCHECK(thread_handle.platform_handle());
 217   // TODO(willchan): Enable this check once I can get it to work for Windows
 218   // shutdown.
 219   // Joining another thread may block the current thread for a long time, since
 220   // the thread referred to by |thread_handle| may still be running long-lived /
 221   // blocking tasks.
 222 #if 0
 223   base::ThreadRestrictions::AssertIOAllowed();
 224 #endif
 225
 226   // Wait for the thread to exit.  It should already have terminated but make
 227   // sure this assumption is valid.
 228   DWORD result = WaitForSingleObject(thread_handle.platform_handle(), INFINITE);
 229   if (result != WAIT_OBJECT_0) {
 230     // Debug info for bug 127931.
 231     DWORD error = GetLastError();
 232     debug::Alias(&error);
 233     debug::Alias(&result);
 234     CHECK(false);
 235   }
 236
 237   CloseHandle(thread_handle.platform_handle());
 238 }
 239
 240 // static
 241 void PlatformThread::SetThreadPriority(PlatformThreadHandle handle,
 242                                        ThreadPriority priority) {
 243   DCHECK(!handle.is_null());
 244
 245   int desired_priority = THREAD_PRIORITY_ERROR_RETURN;
 246   switch (priority) {
 247     case ThreadPriority::BACKGROUND:
 248       desired_priority = THREAD_PRIORITY_LOWEST;
 249       break;
 250     case ThreadPriority::NORMAL:
 251       desired_priority = THREAD_PRIORITY_NORMAL;
 252       break;
 253     case ThreadPriority::DISPLAY:
 254       desired_priority = THREAD_PRIORITY_ABOVE_NORMAL;
 255       break;
 256     case ThreadPriority::REALTIME_AUDIO:
 257       desired_priority = THREAD_PRIORITY_TIME_CRITICAL;
 258       break;
 259     default:
 260       NOTREACHED() << "Unknown priority.";
 261       break;
 262   }
 263   DCHECK_NE(desired_priority, THREAD_PRIORITY_ERROR_RETURN);
 264
 265 #ifndef NDEBUG
 266   const BOOL success =
 267 #endif
 268       ::SetThreadPriority(handle.platform_handle(), desired_priority);
 269   DPLOG_IF(ERROR, !success) << "Failed to set thread priority to "
 270                             << desired_priority;
 271 }
 272
 273 // static
 274 ThreadPriority PlatformThread::GetThreadPriority(PlatformThreadHandle handle) {
 275   DCHECK(!handle.is_null());
 276
 277   int priority = ::GetThreadPriority(handle.platform_handle());
 278   switch (priority) {
 279     case THREAD_PRIORITY_LOWEST:
 280       return ThreadPriority::BACKGROUND;
 281     case THREAD_PRIORITY_NORMAL:
 282       return ThreadPriority::NORMAL;
 283     case THREAD_PRIORITY_ABOVE_NORMAL:
 284       return ThreadPriority::DISPLAY;
 285     case THREAD_PRIORITY_TIME_CRITICAL:
 286       return ThreadPriority::REALTIME_AUDIO;
 287     case THREAD_PRIORITY_ERROR_RETURN:
 288       DPCHECK(false) << "GetThreadPriority error";  // Falls through.
 289     default:
 290       NOTREACHED() << "Unexpected priority: " << priority;
 291       return ThreadPriority::NORMAL;
 292   }
 293 }
 294
 295 }  // namespace base