michael@0: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #include "base/threading/platform_thread.h"
michael@0: 
michael@0: #include "base/debug/alias.h"
michael@0: #include "base/debug/profiler.h"
michael@0: #include "base/logging.h"
michael@0: #include "base/threading/thread_id_name_manager.h"
michael@0: #include "base/threading/thread_restrictions.h"
michael@0: #include "base/tracked_objects.h"
michael@0: 
michael@0: #include "base/win/windows_version.h"
michael@0: 
michael@0: namespace base {
michael@0: 
michael@0: namespace {
michael@0: 
michael@0: // The information on how to set the thread name comes from
michael@0: // a MSDN article: http://msdn2.microsoft.com/en-us/library/xcb2z8hs.aspx
michael@0: const DWORD kVCThreadNameException = 0x406D1388;
michael@0: 
michael@0: typedef struct tagTHREADNAME_INFO {
michael@0:   DWORD dwType;  // Must be 0x1000.
michael@0:   LPCSTR szName;  // Pointer to name (in user addr space).
michael@0:   DWORD dwThreadID;  // Thread ID (-1=caller thread).
michael@0:   DWORD dwFlags;  // Reserved for future use, must be zero.
michael@0: } THREADNAME_INFO;
michael@0: 
michael@0: // This function has try handling, so it is separated out of its caller.
michael@0: void SetNameInternal(PlatformThreadId thread_id, const char* name) {
michael@0:   THREADNAME_INFO info;
michael@0:   info.dwType = 0x1000;
michael@0:   info.szName = name;
michael@0:   info.dwThreadID = thread_id;
michael@0:   info.dwFlags = 0;
michael@0: 
michael@0:   __try {
michael@0:     RaiseException(kVCThreadNameException, 0, sizeof(info)/sizeof(DWORD),
michael@0:                    reinterpret_cast<DWORD_PTR*>(&info));
michael@0:   } __except(EXCEPTION_CONTINUE_EXECUTION) {
michael@0:   }
michael@0: }
michael@0: 
michael@0: struct ThreadParams {
michael@0:   PlatformThread::Delegate* delegate;
michael@0:   bool joinable;
michael@0: };
michael@0: 
michael@0: DWORD __stdcall ThreadFunc(void* params) {
michael@0:   ThreadParams* thread_params = static_cast<ThreadParams*>(params);
michael@0:   PlatformThread::Delegate* delegate = thread_params->delegate;
michael@0:   if (!thread_params->joinable)
michael@0:     base::ThreadRestrictions::SetSingletonAllowed(false);
michael@0: 
michael@0:   /* Retrieve a copy of the thread handle to use as the key in the
michael@0:    * thread name mapping. */
michael@0:   PlatformThreadHandle::Handle platform_handle;
michael@0:   DuplicateHandle(
michael@0:       GetCurrentProcess(),
michael@0:       GetCurrentThread(),
michael@0:       GetCurrentProcess(),
michael@0:       &platform_handle,
michael@0:       0,
michael@0:       FALSE,
michael@0:       DUPLICATE_SAME_ACCESS);
michael@0: 
michael@0:   ThreadIdNameManager::GetInstance()->RegisterThread(
michael@0:       platform_handle,
michael@0:       PlatformThread::CurrentId());
michael@0: 
michael@0:   delete thread_params;
michael@0:   delegate->ThreadMain();
michael@0: 
michael@0:   ThreadIdNameManager::GetInstance()->RemoveName(
michael@0:       platform_handle,
michael@0:       PlatformThread::CurrentId());
michael@0:   return NULL;
michael@0: }
michael@0: 
michael@0: // CreateThreadInternal() matches PlatformThread::Create(), except that
michael@0: // |out_thread_handle| may be NULL, in which case a non-joinable thread is
michael@0: // created.
michael@0: bool CreateThreadInternal(size_t stack_size,
michael@0:                           PlatformThread::Delegate* delegate,
michael@0:                           PlatformThreadHandle* out_thread_handle) {
michael@0:   unsigned int flags = 0;
michael@0:   if (stack_size > 0 && base::win::GetVersion() >= base::win::VERSION_XP) {
michael@0:     flags = STACK_SIZE_PARAM_IS_A_RESERVATION;
michael@0:   } else {
michael@0:     stack_size = 0;
michael@0:   }
michael@0: 
michael@0:   ThreadParams* params = new ThreadParams;
michael@0:   params->delegate = delegate;
michael@0:   params->joinable = out_thread_handle != NULL;
michael@0: 
michael@0:   // Using CreateThread here vs _beginthreadex makes thread creation a bit
michael@0:   // faster and doesn't require the loader lock to be available.  Our code will
michael@0:   // have to work running on CreateThread() threads anyway, since we run code
michael@0:   // on the Windows thread pool, etc.  For some background on the difference:
michael@0:   //   http://www.microsoft.com/msj/1099/win32/win321099.aspx
michael@0:   void* thread_handle = CreateThread(
michael@0:       NULL, stack_size, ThreadFunc, params, flags, NULL);
michael@0:   if (!thread_handle) {
michael@0:     delete params;
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   if (out_thread_handle)
michael@0:     *out_thread_handle = PlatformThreadHandle(thread_handle);
michael@0:   else
michael@0:     CloseHandle(thread_handle);
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: }  // namespace
michael@0: 
michael@0: // static
michael@0: PlatformThreadId PlatformThread::CurrentId() {
michael@0:   return GetCurrentThreadId();
michael@0: }
michael@0: 
michael@0: // static
michael@0: PlatformThreadHandle PlatformThread::CurrentHandle() {
michael@0:   NOTIMPLEMENTED(); // See OpenThread()
michael@0:   return PlatformThreadHandle();
michael@0: }
michael@0: 
michael@0: // static
michael@0: void PlatformThread::YieldCurrentThread() {
michael@0:   ::Sleep(0);
michael@0: }
michael@0: 
michael@0: // static
michael@0: void PlatformThread::Sleep(TimeDelta duration) {
michael@0:   // When measured with a high resolution clock, Sleep() sometimes returns much
michael@0:   // too early. We may need to call it repeatedly to get the desired duration.
michael@0:   TimeTicks end = TimeTicks::Now() + duration;
michael@0:   TimeTicks now;
michael@0:   while ((now = TimeTicks::Now()) < end)
michael@0:     ::Sleep((end - now).InMillisecondsRoundedUp());
michael@0: }
michael@0: 
michael@0: // static
michael@0: void PlatformThread::SetName(const char* name) {
michael@0:   ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
michael@0: 
michael@0:   // On Windows only, we don't need to tell the profiler about the "BrokerEvent"
michael@0:   // thread, as it exists only in the chrome.exe image, and never spawns or runs
michael@0:   // tasks (items which could be profiled).  This test avoids the notification,
michael@0:   // which would also (as a side effect) initialize the profiler in this unused
michael@0:   // context, including setting up thread local storage, etc.  The performance
michael@0:   // impact is not terrible, but there is no reason to do initialize it.
michael@0:   if (0 != strcmp(name, "BrokerEvent"))
michael@0:     tracked_objects::ThreadData::InitializeThreadContext(name);
michael@0: 
michael@0:   // The debugger needs to be around to catch the name in the exception.  If
michael@0:   // there isn't a debugger, we are just needlessly throwing an exception.
michael@0:   // If this image file is instrumented, we raise the exception anyway
michael@0:   // to provide the profiler with human-readable thread names.
michael@0:   if (!::IsDebuggerPresent() && !base::debug::IsBinaryInstrumented())
michael@0:     return;
michael@0: 
michael@0:   SetNameInternal(CurrentId(), name);
michael@0: }
michael@0: 
michael@0: // static
michael@0: const char* PlatformThread::GetName() {
michael@0:   return ThreadIdNameManager::GetInstance()->GetName(CurrentId());
michael@0: }
michael@0: 
michael@0: // static
michael@0: bool PlatformThread::Create(size_t stack_size, Delegate* delegate,
michael@0:                             PlatformThreadHandle* thread_handle) {
michael@0:   DCHECK(thread_handle);
michael@0:   return CreateThreadInternal(stack_size, delegate, thread_handle);
michael@0: }
michael@0: 
michael@0: // static
michael@0: bool PlatformThread::CreateWithPriority(size_t stack_size, Delegate* delegate,
michael@0:                                         PlatformThreadHandle* thread_handle,
michael@0:                                         ThreadPriority priority) {
michael@0:   bool result = Create(stack_size, delegate, thread_handle);
michael@0:   if (result)
michael@0:     SetThreadPriority(*thread_handle, priority);
michael@0:   return result;
michael@0: }
michael@0: 
michael@0: // static
michael@0: bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
michael@0:   return CreateThreadInternal(stack_size, delegate, NULL);
michael@0: }
michael@0: 
michael@0: // static
michael@0: void PlatformThread::Join(PlatformThreadHandle thread_handle) {
michael@0:   DCHECK(thread_handle.handle_);
michael@0:   // TODO(willchan): Enable this check once I can get it to work for Windows
michael@0:   // shutdown.
michael@0:   // Joining another thread may block the current thread for a long time, since
michael@0:   // the thread referred to by |thread_handle| may still be running long-lived /
michael@0:   // blocking tasks.
michael@0: #if 0
michael@0:   base::ThreadRestrictions::AssertIOAllowed();
michael@0: #endif
michael@0: 
michael@0:   // Wait for the thread to exit.  It should already have terminated but make
michael@0:   // sure this assumption is valid.
michael@0:   DWORD result = WaitForSingleObject(thread_handle.handle_, INFINITE);
michael@0:   if (result != WAIT_OBJECT_0) {
michael@0:     // Debug info for bug 127931.
michael@0:     DWORD error = GetLastError();
michael@0:     debug::Alias(&error);
michael@0:     debug::Alias(&result);
michael@0:     debug::Alias(&thread_handle.handle_);
michael@0:     CHECK(false);
michael@0:   }
michael@0: 
michael@0:   CloseHandle(thread_handle.handle_);
michael@0: }
michael@0: 
michael@0: // static
michael@0: void PlatformThread::SetThreadPriority(PlatformThreadHandle handle,
michael@0:                                        ThreadPriority priority) {
michael@0:   switch (priority) {
michael@0:     case kThreadPriority_Normal:
michael@0:       ::SetThreadPriority(handle.handle_, THREAD_PRIORITY_NORMAL);
michael@0:       break;
michael@0:     case kThreadPriority_RealtimeAudio:
michael@0:       ::SetThreadPriority(handle.handle_, THREAD_PRIORITY_TIME_CRITICAL);
michael@0:       break;
michael@0:     default:
michael@0:       NOTREACHED() << "Unknown priority.";
michael@0:       break;
michael@0:   }
michael@0: }
michael@0: 
michael@0: }  // namespace base