blob: e5d57df5a0ba4ed095c4b6a71b66f56caf9fb14c [file] [log] [blame]
// Copyright (c) 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 <vector>
#include "base/base_export.h"
#include "base/callback.h"
#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/sequenced_task_runner.h"
#include "base/synchronization/lock.h"
#include "base/time/time.h"
#include "base/tracked_objects.h"
namespace base {
// A DeferredSequencedTaskRunner is a subclass of SequencedTaskRunner that
// queues up all requests until the first call to Start() is issued.
class BASE_EXPORT DeferredSequencedTaskRunner : public SequencedTaskRunner {
explicit DeferredSequencedTaskRunner(
scoped_refptr<SequencedTaskRunner> target_runner);
// TaskRunner implementation
bool PostDelayedTask(const tracked_objects::Location& from_here,
const Closure& task,
TimeDelta delay) override;
bool RunsTasksOnCurrentThread() const override;
// SequencedTaskRunner implementation
bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
const Closure& task,
TimeDelta delay) override;
// Start the execution - posts all queued tasks to the target executor. The
// deferred tasks are posted with their initial delay, meaning that the task
// execution delay is actually measured from Start.
// Fails when called a second time.
void Start();
struct DeferredTask {
DeferredTask(const DeferredTask& other);
tracked_objects::Location posted_from;
Closure task;
// The delay this task was initially posted with.
TimeDelta delay;
bool is_non_nestable;
~DeferredSequencedTaskRunner() override;
// Creates a |Task| object and adds it to |deferred_tasks_queue_|.
void QueueDeferredTask(const tracked_objects::Location& from_here,
const Closure& task,
TimeDelta delay,
bool is_non_nestable);
// // Protects |started_| and |deferred_tasks_queue_|.
mutable Lock lock_;
bool started_;
const scoped_refptr<SequencedTaskRunner> target_task_runner_;
std::vector<DeferredTask> deferred_tasks_queue_;
} // namespace base