Revert 212948 "Made MessagePump a non-thread safe class."

trunk/src/base/message_loop/incoming_task_queue.cc

Index: trunk/src/base/message_loop/incoming_task_queue.cc
===================================================================
--- trunk/src/base/message_loop/incoming_task_queue.cc	(revision 212951)
+++ trunk/src/base/message_loop/incoming_task_queue.cc	(working copy)
@@ -1,169 +0,0 @@
-// Copyright 2013 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/message_loop/incoming_task_queue.h"
-
-#include "base/debug/trace_event.h"
-#include "base/location.h"
-#include "base/message_loop/message_loop.h"
-#include "base/synchronization/waitable_event.h"
-
-namespace base {
-namespace internal {
-
-IncomingTaskQueue::IncomingTaskQueue(MessageLoop* message_loop)
-    : message_loop_(message_loop),
-      next_sequence_num_(0) {
-}
-
-bool IncomingTaskQueue::AddToIncomingQueue(
-    const tracked_objects::Location& from_here,
-    const Closure& task,
-    TimeDelta delay,
-    bool nestable) {
-  AutoLock locked(incoming_queue_lock_);
-  PendingTask pending_task(
-      from_here, task, CalculateDelayedRuntime(delay), nestable);
-  return PostPendingTask(&pending_task);
-}
-
-bool IncomingTaskQueue::TryAddToIncomingQueue(
-    const tracked_objects::Location& from_here,
-    const Closure& task) {
-  if (!incoming_queue_lock_.Try()) {
-    // Reset |task|.
-    Closure local_task = task;
-    return false;
-  }
-
-  AutoLock locked(incoming_queue_lock_, AutoLock::AlreadyAcquired());
-  PendingTask pending_task(
-      from_here, task, CalculateDelayedRuntime(TimeDelta()), true);
-  return PostPendingTask(&pending_task);
-}
-
-bool IncomingTaskQueue::IsHighResolutionTimerEnabledForTesting() {
-#if defined(OS_WIN)
-  return !high_resolution_timer_expiration_.is_null();
-#else
-  return true;
-#endif
-}
-
-bool IncomingTaskQueue::IsIdleForTesting() {
-  AutoLock lock(incoming_queue_lock_);
-  return incoming_queue_.empty();
-}
-
-void IncomingTaskQueue::LockWaitUnLockForTesting(WaitableEvent* caller_wait,
-                                                 WaitableEvent* caller_signal) {
-  AutoLock lock(incoming_queue_lock_);
-  caller_wait->Signal();
-  caller_signal->Wait();
-}
-
-void IncomingTaskQueue::ReloadWorkQueue(TaskQueue* work_queue) {
-  // Make sure no tasks are lost.
-  DCHECK(work_queue->empty());
-
-  // Acquire all we can from the inter-thread queue with one lock acquisition.
-  AutoLock lock(incoming_queue_lock_);
-  if (!incoming_queue_.empty())
-    incoming_queue_.Swap(work_queue);  // Constant time
-
-  DCHECK(incoming_queue_.empty());
-}
-
-void IncomingTaskQueue::WillDestroyCurrentMessageLoop() {
-#if defined(OS_WIN)
-  // If we left the high-resolution timer activated, deactivate it now.
-  // Doing this is not-critical, it is mainly to make sure we track
-  // the high resolution timer activations properly in our unit tests.
-  if (!high_resolution_timer_expiration_.is_null()) {
-    Time::ActivateHighResolutionTimer(false);
-    high_resolution_timer_expiration_ = TimeTicks();
-  }
-#endif
-
-  AutoLock lock(incoming_queue_lock_);
-  message_loop_ = NULL;
-}
-
-IncomingTaskQueue::~IncomingTaskQueue() {
-  // Verify that WillDestroyCurrentMessageLoop() has been called.
-  DCHECK(!message_loop_);
-}
-
-TimeTicks IncomingTaskQueue::CalculateDelayedRuntime(TimeDelta delay) {
-  TimeTicks delayed_run_time;
-  if (delay > TimeDelta()) {
-    delayed_run_time = TimeTicks::Now() + delay;
-
-#if defined(OS_WIN)
-    if (high_resolution_timer_expiration_.is_null()) {
-      // Windows timers are granular to 15.6ms.  If we only set high-res
-      // timers for those under 15.6ms, then a 18ms timer ticks at ~32ms,
-      // which as a percentage is pretty inaccurate.  So enable high
-      // res timers for any timer which is within 2x of the granularity.
-      // This is a tradeoff between accuracy and power management.
-      bool needs_high_res_timers = delay.InMilliseconds() <
-          (2 * Time::kMinLowResolutionThresholdMs);
-      if (needs_high_res_timers) {
-        if (Time::ActivateHighResolutionTimer(true)) {
-          high_resolution_timer_expiration_ = TimeTicks::Now() +
-              TimeDelta::FromMilliseconds(
-                  MessageLoop::kHighResolutionTimerModeLeaseTimeMs);
-        }
-      }
-    }
-#endif
-  } else {
-    DCHECK_EQ(delay.InMilliseconds(), 0) << "delay should not be negative";
-  }
-
-#if defined(OS_WIN)
-  if (!high_resolution_timer_expiration_.is_null()) {
-    if (TimeTicks::Now() > high_resolution_timer_expiration_) {
-      Time::ActivateHighResolutionTimer(false);
-      high_resolution_timer_expiration_ = TimeTicks();
-    }
-  }
-#endif
-
-  return delayed_run_time;
-}
-
-bool IncomingTaskQueue::PostPendingTask(PendingTask* pending_task) {
-  // Warning: Don't try to short-circuit, and handle this thread's tasks more
-  // directly, as it could starve handling of foreign threads.  Put every task
-  // into this queue.
-
-  // This should only be called while the lock is taken.
-  incoming_queue_lock_.AssertAcquired();
-
-  if (!message_loop_) {
-    pending_task->task.Reset();
-    return false;
-  }
-
-  // Initialize the sequence number. The sequence number is used for delayed
-  // tasks (to faciliate FIFO sorting when two tasks have the same
-  // delayed_run_time value) and for identifying the task in about:tracing.
-  pending_task->sequence_num = next_sequence_num_++;
-
-  TRACE_EVENT_FLOW_BEGIN0("task", "MessageLoop::PostTask",
-      TRACE_ID_MANGLE(message_loop_->GetTaskTraceID(*pending_task)));
-
-  bool was_empty = incoming_queue_.empty();
-  incoming_queue_.push(*pending_task);
-  pending_task->task.Reset();
-
-  // Wake up the pump.
-  message_loop_->ScheduleWork(was_empty);
-
-  return true;
-}
-
-}  // namespace internal
-}  // namespace base