Repo created

TMessagesProj/jni/voip/webrtc/base/at_exit.h

@@ -0,0 +1,87 @@
+// 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_
+
+#include "base/base_export.h"
+#include "base/callback.h"
+#include "base/containers/stack.h"
+#include "base/macros.h"
+#include "base/synchronization/lock.h"
+#include "base/thread_annotations.h"
+
+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(void*).
+  static void RegisterCallback(AtExitCallbackType func, void* param);
+
+  // Registers the specified task to be called at exit.
+  static void RegisterTask(base::OnceClosure task);
+
+  // Calls the functions registered with RegisterCallback in LIFO order. It
+  // is possible to register new callbacks after calling this function.
+  static void ProcessCallbacksNow();
+
+  // Disable all registered at-exit callbacks. This is used only in a single-
+  // process mode.
+  static void DisableAllAtExitManagers();
+
+ 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:
+  base::Lock lock_;
+
+  base::stack<base::OnceClosure> stack_ GUARDED_BY(lock_);
+
+#if DCHECK_IS_ON()
+  bool processing_callbacks_ GUARDED_BY(lock_) = false;
+#endif
+
+  // Stack of managers to allow shadowing.
+  AtExitManager* const next_manager_;
+
+  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_