Add trace code to track all posted tasks in message_loop.

base/threading/worker_pool_posix.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/threading/worker_pool_posix.h"
 
 #include "base/bind.h"
+#include "base/debug/trace_event.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/stringprintf.h"
 #include "base/task.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/worker_pool.h"
 #include "base/tracked_objects.h"
 
 namespace base {
@@ skipping 58 matching lines @@
 
 void WorkerThread::ThreadMain() {
   const std::string name = base::StringPrintf(
       "%s/%d", name_prefix_.c_str(), PlatformThread::CurrentId());
   PlatformThread::SetName(name.c_str());
 
   for (;;) {
     PosixDynamicThreadPool::PendingTask pending_task = pool_->WaitForTask();
     if (pending_task.task.is_null())
       break;
+    UNSHIPPED_TRACE_EVENT2("task", "WorkerThread::ThreadMain::Run",
+        "src_file", pending_task.posted_from.file_name(),
+        "src_func", pending_task.posted_from.function_name());
     pending_task.task.Run();
   }
 
   // The WorkerThread is non-joinable, so it deletes itself.
   delete this;
 }
 
 }  // namespace
 
 bool WorkerPool::PostTask(const tracked_objects::Location& from_here,
                           Task* task, bool task_is_slow) {
   g_lazy_worker_pool.Pointer()->PostTask(from_here, task, task_is_slow);
   return true;
 }
 
 bool WorkerPool::PostTask(const tracked_objects::Location& from_here,
                           const base::Closure& task, bool task_is_slow) {
   g_lazy_worker_pool.Pointer()->PostTask(from_here, task, task_is_slow);
   return true;
 }
 
 PosixDynamicThreadPool::PendingTask::PendingTask(
     const tracked_objects::Location& posted_from,
     const base::Closure& task)
-    : task(task) {
+    : posted_from(posted_from),
+      task(task) {
 }
 
 PosixDynamicThreadPool::PendingTask::~PendingTask() {
 }
 
 PosixDynamicThreadPool::PosixDynamicThreadPool(
     const std::string& name_prefix,
     int idle_seconds_before_exit)
     : name_prefix_(name_prefix),
       idle_seconds_before_exit_(idle_seconds_before_exit),
@@ skipping 81 matching lines @@
       return PendingTask(FROM_HERE, base::Closure());
     }
   }
 
   PendingTask pending_task = pending_tasks_.front();
   pending_tasks_.pop();
   return pending_task;
 }
 
 }  // namespace base