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
DelayedUniqueNotifier(base::SequencedTaskRunner * task_runner,const base::Closure & closure,const base::TimeDelta & delay)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
~DelayedUniqueNotifier()25 DelayedUniqueNotifier::~DelayedUniqueNotifier() {
26 }
27
Schedule()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
Cancel()42 void DelayedUniqueNotifier::Cancel() {
43 next_notification_time_ = base::TimeTicks();
44 }
45
HasPendingNotification() const46 bool DelayedUniqueNotifier::HasPendingNotification() const {
47 return notification_pending_ && !next_notification_time_.is_null();
48 }
49
Now() const50 base::TimeTicks DelayedUniqueNotifier::Now() const {
51 return base::TimeTicks::Now();
52 }
53
NotifyIfTime()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