56 lines
1.5 KiB
C
56 lines
1.5 KiB
C
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// Copyright 2021 The Chromium Authors
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef BASE_TASK_DELAYED_TASK_HANDLE_H_
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#define BASE_TASK_DELAYED_TASK_HANDLE_H_
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#include <memory>
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#include "base/base_export.h"
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namespace base {
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// A handle to a delayed task which can be used to cancel the posted task. Not
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// thread-safe, can only be held and invoked from the posting sequence.
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class BASE_EXPORT DelayedTaskHandle {
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public:
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// The delegate that allows each SequencedTaskRunners to have different
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// implementations.
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class Delegate {
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public:
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virtual ~Delegate() = default;
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// Returns true if the task handle is valid.
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virtual bool IsValid() const = 0;
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// Cancels the task. A canceled task, whether removed from the underlying
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// queue or only marked as canceled, will never be Run().
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virtual void CancelTask() = 0;
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};
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// Construct a default, invalid, task handle.
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DelayedTaskHandle();
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// Construct a valid task handle with the specified |delegate|.
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explicit DelayedTaskHandle(std::unique_ptr<Delegate> delegate);
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~DelayedTaskHandle();
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DelayedTaskHandle(DelayedTaskHandle&&);
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DelayedTaskHandle& operator=(DelayedTaskHandle&&);
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// Returns true if the task handle is valid.
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bool IsValid() const;
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// Cancels the task.
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void CancelTask();
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private:
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std::unique_ptr<Delegate> delegate_;
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};
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} // namespace base
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#endif // BASE_TASK_DELAYED_TASK_HANDLE_H_
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