Support for registering arbitrary Tasks with AtExitManager.

base/at_exit.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_AT_EXIT_H_
 #define BASE_AT_EXIT_H_
 #pragma once
 
 #include <stack>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
+#include "base/memory/linked_ptr.h"
 #include "base/synchronization/lock.h"
 
+class Task;
+
 namespace base {
 
 // This class provides a facility similar to the CRT atexit(), except that
 // we control when the callbacks are executed. Under Windows for a DLL they
 // happen at a really bad time and under the loader lock. This facility is
 // mostly used by base::Singleton.
 //
 // The usage is simple. Early in the main() or WinMain() scope create an
 // AtExitManager object on the stack:
 // int main(...) {
 //    base::AtExitManager exit_manager;
 //
 // }
 // When the exit_manager object goes out of scope, all the registered
 // callbacks and singleton destructors will be called.
 
 class BASE_EXPORT AtExitManager {
  public:
   typedef void (*AtExitCallbackType)(void*);
 
   AtExitManager();
 
   // The dtor calls all the registered callbacks. Do not try to register more
   // callbacks after this point.
   ~AtExitManager();
 
   // Registers the specified function to be called at exit. The prototype of
-  // the callback function is void func().
+  // the callback function is void func(void*).
   static void RegisterCallback(AtExitCallbackType func, void* param);
 
+  // Registers the specified task to be called at exit. The task is deleted
+  // after it runs.
+  static void RegisterTask(Task* task);

[darin (slow to review), 2011/09/01 23:35:44]

how about using base::Closure instead?

+
   // Calls the functions registered with RegisterCallback in LIFO order. It
   // is possible to register new callbacks after calling this function.
   static void ProcessCallbacksNow();
 
  protected:
   // This constructor will allow this instance of AtExitManager to be created
   // even if one already exists.  This should only be used for testing!
   // AtExitManagers are kept on a global stack, and it will be removed during
   // destruction.  This allows you to shadow another AtExitManager.
   explicit AtExitManager(bool shadow);
 
  private:
-  struct CallbackAndParam {
-    CallbackAndParam(AtExitCallbackType func, void* param)
-        : func_(func), param_(param) { }
-    AtExitCallbackType func_;
-    void* param_;
-  };
-
   base::Lock lock_;
-  std::stack<CallbackAndParam> stack_;
+  std::stack<linked_ptr<Task> > stack_;
   AtExitManager* next_manager_;  // Stack of managers to allow shadowing.
 
   DISALLOW_COPY_AND_ASSIGN(AtExitManager);
 };
 
 #if defined(UNIT_TEST)
 class ShadowingAtExitManager : public AtExitManager {
  public:
   ShadowingAtExitManager() : AtExitManager(true) {}
 };
 #endif  // defined(UNIT_TEST)
 
 }  // namespace base
 
 #endif  // BASE_AT_EXIT_H_