1// Copyright 2013 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 "cc/trees/blocking_task_runner.h"
6
7#include <utility>
8
9#include "base/callback.h"
10#include "base/logging.h"
11#include "base/message_loop/message_loop_proxy.h"
12
13namespace cc {
14
15// static
16scoped_ptr<BlockingTaskRunner> BlockingTaskRunner::Create(
17    scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
18  return make_scoped_ptr(new BlockingTaskRunner(task_runner));
19}
20
21BlockingTaskRunner::BlockingTaskRunner(
22    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
23    : thread_id_(base::PlatformThread::CurrentId()),
24      task_runner_(task_runner),
25      capture_(0) {
26}
27
28BlockingTaskRunner::~BlockingTaskRunner() {}
29
30bool BlockingTaskRunner::BelongsToCurrentThread() {
31  return base::PlatformThread::CurrentId() == thread_id_;
32}
33
34bool BlockingTaskRunner::PostTask(const tracked_objects::Location& from_here,
35                                  const base::Closure& task) {
36  base::AutoLock lock(lock_);
37  DCHECK(task_runner_.get() || capture_);
38  if (!capture_)
39    return task_runner_->PostTask(from_here, task);
40  captured_tasks_.push_back(task);
41  return true;
42}
43
44void BlockingTaskRunner::SetCapture(bool capture) {
45  DCHECK(BelongsToCurrentThread());
46
47  std::vector<base::Closure> tasks;
48
49  {
50    base::AutoLock lock(lock_);
51    capture_ += capture ? 1 : -1;
52    DCHECK_GE(capture_, 0);
53
54    if (capture_)
55      return;
56
57    // We're done capturing, so grab all the captured tasks and run them.
58    tasks.swap(captured_tasks_);
59  }
60  for (size_t i = 0; i < tasks.size(); ++i)
61    tasks[i].Run();
62}
63
64BlockingTaskRunner::CapturePostTasks::CapturePostTasks(
65    BlockingTaskRunner* blocking_runner)
66    : blocking_runner_(blocking_runner) {
67  blocking_runner_->SetCapture(true);
68}
69
70BlockingTaskRunner::CapturePostTasks::~CapturePostTasks() {
71  blocking_runner_->SetCapture(false);
72}
73
74}  // namespace cc
75