1// Copyright (c) 2012 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 "content/browser/notification_service_impl.h"
6
7#include "base/lazy_instance.h"
8#include "base/threading/thread_local.h"
9#include "content/public/browser/notification_observer.h"
10#include "content/public/browser/notification_types.h"
11
12namespace  content {
13
14namespace {
15
16base::LazyInstance<base::ThreadLocalPointer<NotificationServiceImpl> >
17    lazy_tls_ptr = LAZY_INSTANCE_INITIALIZER;
18
19}  // namespace
20
21// static
22NotificationServiceImpl* NotificationServiceImpl::current() {
23  return lazy_tls_ptr.Pointer()->Get();
24}
25
26// static
27NotificationService* NotificationService::current() {
28  return NotificationServiceImpl::current();
29}
30
31// static
32NotificationService* NotificationService::Create() {
33  return new NotificationServiceImpl;
34}
35
36// static
37bool NotificationServiceImpl::HasKey(const NotificationSourceMap& map,
38                                     const NotificationSource& source) {
39  return map.find(source.map_key()) != map.end();
40}
41
42NotificationServiceImpl::NotificationServiceImpl() {
43  DCHECK(current() == NULL);
44  lazy_tls_ptr.Pointer()->Set(this);
45}
46
47void NotificationServiceImpl::AddObserver(NotificationObserver* observer,
48                                          int type,
49                                          const NotificationSource& source) {
50  // We have gotten some crashes where the observer pointer is NULL. The problem
51  // is that this happens when we actually execute a notification, so have no
52  // way of knowing who the bad observer was. We want to know when this happens
53  // in release mode so we know what code to blame the crash on (since this is
54  // guaranteed to crash later).
55  CHECK(observer);
56
57  NotificationObserverList* observer_list;
58  if (HasKey(observers_[type], source)) {
59    observer_list = observers_[type][source.map_key()];
60  } else {
61    observer_list = new NotificationObserverList;
62    observers_[type][source.map_key()] = observer_list;
63  }
64
65  observer_list->AddObserver(observer);
66#ifndef NDEBUG
67  ++observer_counts_[type];
68#endif
69}
70
71void NotificationServiceImpl::RemoveObserver(NotificationObserver* observer,
72                                             int type,
73                                             const NotificationSource& source) {
74  // This is a very serious bug.  An object is most likely being deleted on
75  // the wrong thread, and as a result another thread's NotificationServiceImpl
76  // has its deleted pointer in its map.  A garbge object will be called in the
77  // future.
78  // NOTE: when this check shows crashes, use BrowserThread::DeleteOnIOThread or
79  // other variants as the trait on the object.
80  CHECK(HasKey(observers_[type], source));
81
82  NotificationObserverList* observer_list =
83      observers_[type][source.map_key()];
84  if (observer_list) {
85    observer_list->RemoveObserver(observer);
86    if (!observer_list->might_have_observers()) {
87      observers_[type].erase(source.map_key());
88      delete observer_list;
89    }
90#ifndef NDEBUG
91    --observer_counts_[type];
92#endif
93  }
94}
95
96void NotificationServiceImpl::Notify(int type,
97                                     const NotificationSource& source,
98                                     const NotificationDetails& details) {
99  DCHECK_GT(type, NOTIFICATION_ALL) <<
100      "Allowed for observing, but not posting.";
101
102  // There's no particular reason for the order in which the different
103  // classes of observers get notified here.
104
105  // Notify observers of all types and all sources
106  if (HasKey(observers_[NOTIFICATION_ALL], AllSources()) &&
107      source != AllSources()) {
108    FOR_EACH_OBSERVER(NotificationObserver,
109                      *observers_[NOTIFICATION_ALL][AllSources().map_key()],
110                      Observe(type, source, details));
111  }
112
113  // Notify observers of all types and the given source
114  if (HasKey(observers_[NOTIFICATION_ALL], source)) {
115    FOR_EACH_OBSERVER(NotificationObserver,
116                      *observers_[NOTIFICATION_ALL][source.map_key()],
117                      Observe(type, source, details));
118  }
119
120  // Notify observers of the given type and all sources
121  if (HasKey(observers_[type], AllSources()) &&
122      source != AllSources()) {
123    FOR_EACH_OBSERVER(NotificationObserver,
124                      *observers_[type][AllSources().map_key()],
125                      Observe(type, source, details));
126  }
127
128  // Notify observers of the given type and the given source
129  if (HasKey(observers_[type], source)) {
130    FOR_EACH_OBSERVER(NotificationObserver,
131                      *observers_[type][source.map_key()],
132                      Observe(type, source, details));
133  }
134}
135
136
137NotificationServiceImpl::~NotificationServiceImpl() {
138  lazy_tls_ptr.Pointer()->Set(NULL);
139
140#ifndef NDEBUG
141  for (int i = 0; i < static_cast<int>(observer_counts_.size()); i++) {
142    if (observer_counts_[i] > 0) {
143      // This may not be completely fixable -- see
144      // http://code.google.com/p/chromium/issues/detail?id=11010 .
145      VLOG(1) << observer_counts_[i] << " notification observer(s) leaked "
146                 "of notification type " << i;
147    }
148  }
149#endif
150
151  for (int i = 0; i < static_cast<int>(observers_.size()); i++) {
152    NotificationSourceMap omap = observers_[i];
153    for (NotificationSourceMap::iterator it = omap.begin();
154         it != omap.end(); ++it)
155      delete it->second;
156  }
157}
158
159}  // namespace content
160