blob: 16cc061648df6e5d9cf8e74c20bb460b6c055a48 [file] [log] [blame]
// Copyright (c) 2012 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.h"
#include "base/bind.h"
#include "base/compiler_specific.h"
#include "base/lazy_instance.h"
#include "base/task_runner.h"
#include "base/threading/post_task_and_reply_impl.h"
#include "base/tracked_objects.h"
namespace base {
namespace {
class PostTaskAndReplyWorkerPool : public internal::PostTaskAndReplyImpl {
public:
PostTaskAndReplyWorkerPool(bool task_is_slow) : task_is_slow_(task_is_slow) {
}
private:
virtual bool PostTask(const tracked_objects::Location& from_here,
const Closure& task) OVERRIDE {
return WorkerPool::PostTask(from_here, task, task_is_slow_);
}
bool task_is_slow_;
};
// WorkerPoolTaskRunner ---------------------------------------------
// A TaskRunner which posts tasks to a WorkerPool with a
// fixed ShutdownBehavior.
//
// Note that this class is RefCountedThreadSafe (inherited from TaskRunner).
class WorkerPoolTaskRunner : public TaskRunner {
public:
WorkerPoolTaskRunner(bool tasks_are_slow);
// TaskRunner implementation
virtual bool PostDelayedTask(const tracked_objects::Location& from_here,
const Closure& task,
TimeDelta delay) OVERRIDE;
virtual bool RunsTasksOnCurrentThread() const OVERRIDE;
private:
virtual ~WorkerPoolTaskRunner();
// Helper function for posting a delayed task. Asserts that the delay is
// zero because non-zero delays are not supported.
bool PostDelayedTaskAssertZeroDelay(
const tracked_objects::Location& from_here,
const Closure& task,
base::TimeDelta delay);
const bool tasks_are_slow_;
DISALLOW_COPY_AND_ASSIGN(WorkerPoolTaskRunner);
};
WorkerPoolTaskRunner::WorkerPoolTaskRunner(bool tasks_are_slow)
: tasks_are_slow_(tasks_are_slow) {
}
WorkerPoolTaskRunner::~WorkerPoolTaskRunner() {
}
bool WorkerPoolTaskRunner::PostDelayedTask(
const tracked_objects::Location& from_here,
const Closure& task,
TimeDelta delay) {
return PostDelayedTaskAssertZeroDelay(from_here, task, delay);
}
bool WorkerPoolTaskRunner::RunsTasksOnCurrentThread() const {
return WorkerPool::RunsTasksOnCurrentThread();
}
bool WorkerPoolTaskRunner::PostDelayedTaskAssertZeroDelay(
const tracked_objects::Location& from_here,
const Closure& task,
base::TimeDelta delay) {
DCHECK_EQ(delay.InMillisecondsRoundedUp(), 0)
<< "WorkerPoolTaskRunner does not support non-zero delays";
return WorkerPool::PostTask(from_here, task, tasks_are_slow_);
}
struct TaskRunnerHolder {
TaskRunnerHolder() {
taskrunners_[0] = new WorkerPoolTaskRunner(false);
taskrunners_[1] = new WorkerPoolTaskRunner(true);
}
scoped_refptr<TaskRunner> taskrunners_[2];
};
base::LazyInstance<TaskRunnerHolder>::Leaky
g_taskrunners = LAZY_INSTANCE_INITIALIZER;
} // namespace
bool WorkerPool::PostTaskAndReply(const tracked_objects::Location& from_here,
const Closure& task,
const Closure& reply,
bool task_is_slow) {
return PostTaskAndReplyWorkerPool(task_is_slow).PostTaskAndReply(
from_here, task, reply);
}
// static
const scoped_refptr<TaskRunner>&
WorkerPool::GetTaskRunner(bool tasks_are_slow) {
return g_taskrunners.Get().taskrunners_[tasks_are_slow];
}
} // namespace base