1// Copyright 2013 the V8 project 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 "src/libplatform/task-queue.h"
6
7#include "include/v8-platform.h"
8#include "src/base/logging.h"
9#include "src/base/platform/platform.h"
10#include "src/base/platform/time.h"
11
12namespace v8 {
13namespace platform {
14
15TaskQueue::TaskQueue() : process_queue_semaphore_(0), terminated_(false) {}
16
17
18TaskQueue::~TaskQueue() {
19  base::MutexGuard guard(&lock_);
20  DCHECK(terminated_);
21  DCHECK(task_queue_.empty());
22}
23
24void TaskQueue::Append(std::unique_ptr<Task> task) {
25  base::MutexGuard guard(&lock_);
26  DCHECK(!terminated_);
27  task_queue_.push(std::move(task));
28  process_queue_semaphore_.Signal();
29}
30
31std::unique_ptr<Task> TaskQueue::GetNext() {
32  for (;;) {
33    {
34      base::MutexGuard guard(&lock_);
35      if (!task_queue_.empty()) {
36        std::unique_ptr<Task> result = std::move(task_queue_.front());
37        task_queue_.pop();
38        return result;
39      }
40      if (terminated_) {
41        process_queue_semaphore_.Signal();
42        return nullptr;
43      }
44    }
45    process_queue_semaphore_.Wait();
46  }
47}
48
49
50void TaskQueue::Terminate() {
51  base::MutexGuard guard(&lock_);
52  DCHECK(!terminated_);
53  terminated_ = true;
54  process_queue_semaphore_.Signal();
55}
56
57void TaskQueue::BlockUntilQueueEmptyForTesting() {
58  for (;;) {
59    {
60      base::MutexGuard guard(&lock_);
61      if (task_queue_.empty()) return;
62    }
63    base::OS::Sleep(base::TimeDelta::FromMilliseconds(5));
64  }
65}
66
67}  // namespace platform
68}  // namespace v8
69