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// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_SCHEDULER_PUBLIC_POST_CANCELLABLE_TASK_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_SCHEDULER_PUBLIC_POST_CANCELLABLE_TASK_H_
#include "base/functional/callback.h"
#include "base/location.h"
#include "base/memory/scoped_refptr.h"
#include "base/task/sequenced_task_runner.h"
#include "base/time/time.h"
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
namespace blink {
// TaskHandle is associated to a task posted by PostCancellableTask() or
// PostCancellableDelayedTask() and cancels the associated task on
// TaskHandle::cancel() call or on TaskHandle destruction.
class PLATFORM_EXPORT TaskHandle {
DISALLOW_NEW();
public:
class Runner;
TaskHandle();
~TaskHandle();
TaskHandle(TaskHandle&&);
TaskHandle& operator=(TaskHandle&&);
// Returns true if the task will run later. Returns false if the task is
// cancelled or the task is run already.
// This function is not thread safe. Call this on the thread that has posted
// the task.
bool IsActive() const;
// Cancels the task invocation. Do nothing if the task is cancelled or run
// already.
// This function is not thread safe. Call this on the thread that has posted
// the task.
void Cancel();
private:
TaskHandle(const TaskHandle&) = delete;
TaskHandle& operator=(const TaskHandle&) = delete;
friend PLATFORM_EXPORT TaskHandle
PostCancellableTask(base::SequencedTaskRunner&,
const base::Location&,
base::OnceClosure);
friend PLATFORM_EXPORT TaskHandle
PostDelayedCancellableTask(base::SequencedTaskRunner&,
const base::Location&,
base::OnceClosure,
base::TimeDelta delay);
friend PLATFORM_EXPORT TaskHandle
PostNonNestableCancellableTask(base::SequencedTaskRunner&,
const base::Location&,
base::OnceClosure);
friend PLATFORM_EXPORT TaskHandle
PostNonNestableDelayedCancellableTask(base::SequencedTaskRunner&,
const base::Location&,
base::OnceClosure,
base::TimeDelta delay);
explicit TaskHandle(scoped_refptr<Runner>);
scoped_refptr<Runner> runner_;
};
// For same-thread cancellable task posting. Returns a TaskHandle object for
// cancellation.
[[nodiscard]] PLATFORM_EXPORT TaskHandle
PostCancellableTask(base::SequencedTaskRunner&,
const base::Location&,
base::OnceClosure);
[[nodiscard]] PLATFORM_EXPORT TaskHandle
PostDelayedCancellableTask(base::SequencedTaskRunner&,
const base::Location&,
base::OnceClosure,
base::TimeDelta delay);
[[nodiscard]] PLATFORM_EXPORT TaskHandle
PostNonNestableCancellableTask(base::SequencedTaskRunner&,
const base::Location&,
base::OnceClosure);
[[nodiscard]] PLATFORM_EXPORT TaskHandle
PostNonNestableDelayedCancellableTask(base::SequencedTaskRunner&,
const base::Location&,
base::OnceClosure,
base::TimeDelta delay);
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_SCHEDULER_PUBLIC_POST_CANCELLABLE_TASK_H_
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