15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2011 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef BASE_AT_EXIT_H_ 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define BASE_AT_EXIT_H_ 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <stack> 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/base_export.h" 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/basictypes.h" 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/callback.h" 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/synchronization/lock.h" 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace base { 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This class provides a facility similar to the CRT atexit(), except that 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// we control when the callbacks are executed. Under Windows for a DLL they 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// happen at a really bad time and under the loader lock. This facility is 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// mostly used by base::Singleton. 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// The usage is simple. Early in the main() or WinMain() scope create an 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// AtExitManager object on the stack: 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// int main(...) { 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// base::AtExitManager exit_manager; 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// } 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// When the exit_manager object goes out of scope, all the registered 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// callbacks and singleton destructors will be called. 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class BASE_EXPORT AtExitManager { 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) typedef void (*AtExitCallbackType)(void*); 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) AtExitManager(); 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The dtor calls all the registered callbacks. Do not try to register more 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // callbacks after this point. 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ~AtExitManager(); 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Registers the specified function to be called at exit. The prototype of 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // the callback function is void func(void*). 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static void RegisterCallback(AtExitCallbackType func, void* param); 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Registers the specified task to be called at exit. 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static void RegisterTask(base::Closure task); 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Calls the functions registered with RegisterCallback in LIFO order. It 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // is possible to register new callbacks after calling this function. 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static void ProcessCallbacksNow(); 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) protected: 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This constructor will allow this instance of AtExitManager to be created 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // even if one already exists. This should only be used for testing! 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // AtExitManagers are kept on a global stack, and it will be removed during 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // destruction. This allows you to shadow another AtExitManager. 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) explicit AtExitManager(bool shadow); 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::Lock lock_; 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) std::stack<base::Closure> stack_; 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) AtExitManager* next_manager_; // Stack of managers to allow shadowing. 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DISALLOW_COPY_AND_ASSIGN(AtExitManager); 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#if defined(UNIT_TEST) 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class ShadowingAtExitManager : public AtExitManager { 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ShadowingAtExitManager() : AtExitManager(true) {} 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // defined(UNIT_TEST) 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace base 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // BASE_AT_EXIT_H_ 77