michael@0: // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #include "base/at_exit.h"
michael@0: #include "base/logging.h"
michael@0: 
michael@0: namespace base {
michael@0: 
michael@0: // Keep a stack of registered AtExitManagers.  We always operate on the most
michael@0: // recent, and we should never have more than one outside of testing, when we
michael@0: // use the shadow version of the constructor.  We don't protect this for
michael@0: // thread-safe access, since it will only be modified in testing.
michael@0: static AtExitManager* g_top_manager = NULL;
michael@0: 
michael@0: AtExitManager::AtExitManager() : next_manager_(NULL) {
michael@0:   DCHECK(!g_top_manager);
michael@0:   g_top_manager = this;
michael@0: }
michael@0: 
michael@0: AtExitManager::AtExitManager(bool shadow) : next_manager_(g_top_manager) {
michael@0:   DCHECK(shadow || !g_top_manager);
michael@0:   g_top_manager = this;
michael@0: }
michael@0: 
michael@0: AtExitManager::~AtExitManager() {
michael@0:   if (!g_top_manager) {
michael@0:     NOTREACHED() << "Tried to ~AtExitManager without an AtExitManager";
michael@0:     return;
michael@0:   }
michael@0:   DCHECK(g_top_manager == this);
michael@0: 
michael@0:   ProcessCallbacksNow();
michael@0:   g_top_manager = next_manager_;
michael@0: }
michael@0: 
michael@0: // static
michael@0: void AtExitManager::RegisterCallback(AtExitCallbackType func, void* param) {
michael@0:   if (!g_top_manager) {
michael@0:     NOTREACHED() << "Tried to RegisterCallback without an AtExitManager";
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   DCHECK(func);
michael@0: 
michael@0:   AutoLock lock(g_top_manager->lock_);
michael@0:   g_top_manager->stack_.push(CallbackAndParam(func, param));
michael@0: }
michael@0: 
michael@0: // static
michael@0: void AtExitManager::ProcessCallbacksNow() {
michael@0:   if (!g_top_manager) {
michael@0:     NOTREACHED() << "Tried to ProcessCallbacksNow without an AtExitManager";
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   AutoLock lock(g_top_manager->lock_);
michael@0: 
michael@0:   while (!g_top_manager->stack_.empty()) {
michael@0:     CallbackAndParam callback_and_param = g_top_manager->stack_.top();
michael@0:     g_top_manager->stack_.pop();
michael@0: 
michael@0:     callback_and_param.func_(callback_and_param.param_);
michael@0:   }
michael@0: }
michael@0: 
michael@0: // static
michael@0: bool AtExitManager::AlreadyRegistered() {
michael@0:   return !!g_top_manager;
michael@0: }
michael@0: 
michael@0: }  // namespace base