1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "cc/base/delayed_unique_notifier.h" 6 7 #include "base/bind.h" 8 #include "base/bind_helpers.h" 9 #include "base/location.h" 10 #include "base/sequenced_task_runner.h" 11 12 namespace cc { 13 14 DelayedUniqueNotifier::DelayedUniqueNotifier( 15 base::SequencedTaskRunner* task_runner, 16 const base::Closure& closure, 17 const base::TimeDelta& delay) 18 : task_runner_(task_runner), 19 closure_(closure), 20 delay_(delay), 21 notification_pending_(false), 22 weak_ptr_factory_(this) { 23 } 24 25 DelayedUniqueNotifier::~DelayedUniqueNotifier() { 26 } 27 28 void DelayedUniqueNotifier::Schedule() { 29 if (notification_pending_) { 30 next_notification_time_ = Now() + delay_; 31 return; 32 } 33 34 next_notification_time_ = Now() + delay_; 35 task_runner_->PostDelayedTask(FROM_HERE, 36 base::Bind(&DelayedUniqueNotifier::NotifyIfTime, 37 weak_ptr_factory_.GetWeakPtr()), 38 delay_); 39 notification_pending_ = true; 40 } 41 42 void DelayedUniqueNotifier::Cancel() { 43 next_notification_time_ = base::TimeTicks(); 44 } 45 46 bool DelayedUniqueNotifier::HasPendingNotification() const { 47 return notification_pending_ && !next_notification_time_.is_null(); 48 } 49 50 base::TimeTicks DelayedUniqueNotifier::Now() const { 51 return base::TimeTicks::Now(); 52 } 53 54 void DelayedUniqueNotifier::NotifyIfTime() { 55 // If next notifiaction time is not valid, then this schedule was canceled. 56 if (next_notification_time_.is_null()) { 57 notification_pending_ = false; 58 return; 59 } 60 61 // If the notification was rescheduled or arrived too early for any other 62 // reason, then post another task instead of running the callback. 63 base::TimeTicks now = Now(); 64 if (next_notification_time_ > now) { 65 task_runner_->PostDelayedTask( 66 FROM_HERE, 67 base::Bind(&DelayedUniqueNotifier::NotifyIfTime, 68 weak_ptr_factory_.GetWeakPtr()), 69 next_notification_time_ - now); 70 return; 71 } 72 73 // Note the order here is important since closure might schedule another run. 74 notification_pending_ = false; 75 closure_.Run(); 76 } 77 78 } // namespace cc 79