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      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/worker_pool.h"
      6 
      7 #include "base/bind.h"
      8 #include "base/callback.h"
      9 #include "base/debug/trace_event.h"
     10 #include "base/logging.h"
     11 #include "base/pending_task.h"
     12 #include "base/threading/thread_local.h"
     13 #include "base/tracked_objects.h"
     14 
     15 namespace base {
     16 
     17 namespace {
     18 
     19 base::LazyInstance<ThreadLocalBoolean>::Leaky
     20     g_worker_pool_running_on_this_thread = LAZY_INSTANCE_INITIALIZER;
     21 
     22 DWORD CALLBACK WorkItemCallback(void* param) {
     23   PendingTask* pending_task = static_cast<PendingTask*>(param);
     24   TRACE_EVENT2("task", "WorkItemCallback::Run",
     25                "src_file", pending_task->posted_from.file_name(),
     26                "src_func", pending_task->posted_from.function_name());
     27 
     28   tracked_objects::TrackedTime start_time =
     29       tracked_objects::ThreadData::NowForStartOfRun(pending_task->birth_tally);
     30 
     31   g_worker_pool_running_on_this_thread.Get().Set(true);
     32   pending_task->task.Run();
     33   g_worker_pool_running_on_this_thread.Get().Set(false);
     34 
     35   tracked_objects::ThreadData::TallyRunOnWorkerThreadIfTracking(
     36       pending_task->birth_tally,
     37       tracked_objects::TrackedTime(pending_task->time_posted), start_time,
     38       tracked_objects::ThreadData::NowForEndOfRun());
     39 
     40   delete pending_task;
     41   return 0;
     42 }
     43 
     44 // Takes ownership of |pending_task|
     45 bool PostTaskInternal(PendingTask* pending_task, bool task_is_slow) {
     46   ULONG flags = 0;
     47   if (task_is_slow)
     48     flags |= WT_EXECUTELONGFUNCTION;
     49 
     50   if (!QueueUserWorkItem(WorkItemCallback, pending_task, flags)) {
     51     DLOG_GETLASTERROR(ERROR) << "QueueUserWorkItem failed";
     52     delete pending_task;
     53     return false;
     54   }
     55 
     56   return true;
     57 }
     58 
     59 }  // namespace
     60 
     61 // static
     62 bool WorkerPool::PostTask(const tracked_objects::Location& from_here,
     63                           const base::Closure& task, bool task_is_slow) {
     64   PendingTask* pending_task = new PendingTask(from_here, task);
     65   return PostTaskInternal(pending_task, task_is_slow);
     66 }
     67 
     68 // static
     69 bool WorkerPool::RunsTasksOnCurrentThread() {
     70   return g_worker_pool_running_on_this_thread.Get().Get();
     71 }
     72 
     73 }  // namespace base
     74