base/message_loop/message_loop_proxy.h

   1 // Copyright (c) 2012 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 #ifndef BASE_MESSAGE_LOOP_MESSAGE_LOOP_PROXY_H_
   6 #define BASE_MESSAGE_LOOP_MESSAGE_LOOP_PROXY_H_
   7
   8 #include "base/base_export.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/memory/ref_counted.h"
  11 #include "base/single_thread_task_runner.h"
  12
  13 namespace base {
  14
  15 // This class provides a thread-safe refcounted interface to the Post* methods
  16 // of a message loop. This class can outlive the target message loop.
  17 // MessageLoopProxy objects are constructed automatically for all MessageLoops.
  18 // So, to access them, you can use any of the following:
  19 //   Thread::message_loop_proxy()
  20 //   MessageLoop::current()->message_loop_proxy()
  21 //   MessageLoopProxy::current()
  22 //
  23 // TODO(akalin): Now that we have the *TaskRunner interfaces, we can
  24 // merge this with MessageLoopProxyImpl.
  25 class BASE_EXPORT MessageLoopProxy : public SingleThreadTaskRunner {
  26  public:
  27   // Gets the MessageLoopProxy for the current message loop, creating one if
  28   // needed.
  29   static scoped_refptr<MessageLoopProxy> current();
  30
  31  protected:
  32   MessageLoopProxy();
  33   ~MessageLoopProxy() override;
  34 };
  35
  36 }  // namespace base
  37
  38 #endif  // BASE_MESSAGE_LOOP_MESSAGE_LOOP_PROXY_H_