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