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// Copyright 2014 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/callback.h"
#include "base/memory/weak_ptr.h"
#include "cc/base/base_export.h"
namespace base {
class SequencedTaskRunner;
} // namespace base
namespace cc {
class CC_BASE_EXPORT DelayedUniqueNotifier {
// Configure this notifier to issue the |closure| notification in |delay| time
// from Schedule() call.
DelayedUniqueNotifier(base::SequencedTaskRunner* task_runner,
base::RepeatingClosure closure,
const base::TimeDelta& delay);
DelayedUniqueNotifier(const DelayedUniqueNotifier&) = delete;
// Destroying the notifier will ensure that no further notifications will
// happen from this class.
virtual ~DelayedUniqueNotifier();
DelayedUniqueNotifier& operator=(const DelayedUniqueNotifier&) = delete;
// Schedule a notification to be run. If another notification is already
// pending, then it will happen in (at least) given delay from now. That is,
// if delay is 16ms and a notification has been scheduled 10ms ago (ie, it
// should trigger in no less than 6ms), then calling schedule will ensure that
// the only notification that arrives will happen in (at least) 16ms from now.
void Schedule();
// Cancel any previously scheduled runs.
void Cancel();
// Cancel previously scheduled runs and prevent any new runs from starting.
// After calling this the DelayedUniqueNotifier will have no outstanding
// WeakPtrs.
void Shutdown();
// Returns true if a notification is currently scheduled to run.
bool HasPendingNotification() const;
base::TimeDelta delay() const { return delay_; }
// Virtual for testing.
virtual base::TimeTicks Now() const;
void NotifyIfTime();
base::SequencedTaskRunner* const task_runner_;
const base::RepeatingClosure closure_;
const base::TimeDelta delay_;
// Lock should be held before modifying |next_notification_time_| or
// |notification_pending_|.
mutable base::Lock lock_;
base::TimeTicks next_notification_time_;
bool notification_pending_;
base::WeakPtrFactory<DelayedUniqueNotifier> weak_ptr_factory_{this};
} // namespace cc