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