at_exit.cc revision ddb351dbec246cf1fab5ec20d2d5520909041de1 
1// Copyright (c) 2011 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 "base/at_exit.h"
6
7#include <stddef.h>
8#include <ostream>
9
10#include "base/logging.h"
11
12namespace base {
13
14// Keep a stack of registered AtExitManagers.  We always operate on the most
15// recent, and we should never have more than one outside of testing, when we
16// use the shadow version of the constructor.  We don't protect this for
17// thread-safe access, since it will only be modified in testing.
18static AtExitManager* g_top_manager = NULL;
19
20AtExitManager::AtExitManager() : next_manager_(NULL) {
21  DCHECK(!g_top_manager);
22  g_top_manager = this;
23}
24
25AtExitManager::~AtExitManager() {
26  if (!g_top_manager) {
27    NOTREACHED() << "Tried to ~AtExitManager without an AtExitManager";
28    return;
29  }
30  DCHECK(g_top_manager == this);
31
32  ProcessCallbacksNow();
33  g_top_manager = next_manager_;
34}
35
36// static
37void AtExitManager::RegisterCallback(AtExitCallbackType func, void* param) {
38  if (!g_top_manager) {
39    NOTREACHED() << "Tried to RegisterCallback without an AtExitManager";
40    return;
41  }
42
43  DCHECK(func);
44
45  AutoLock lock(g_top_manager->lock_);
46  g_top_manager->stack_.push(CallbackAndParam(func, param));
47}
48
49// static
50void AtExitManager::ProcessCallbacksNow() {
51  if (!g_top_manager) {
52    NOTREACHED() << "Tried to ProcessCallbacksNow without an AtExitManager";
53    return;
54  }
55
56  AutoLock lock(g_top_manager->lock_);
57
58  while (!g_top_manager->stack_.empty()) {
59    CallbackAndParam callback_and_param = g_top_manager->stack_.top();
60    g_top_manager->stack_.pop();
61
62    callback_and_param.func_(callback_and_param.param_);
63  }
64}
65
66AtExitManager::AtExitManager(bool shadow) : next_manager_(g_top_manager) {
67  DCHECK(shadow || !g_top_manager);
68  g_top_manager = this;
69}
70
71}  // namespace base
72