ipc/mojo/async_handle_waiter.h

   1 // Copyright 2015 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 IPC_MOJO_ASYNC_HANDLE_WAITER_H_
   6 #define IPC_MOJO_ASYNC_HANDLE_WAITER_H_
   7
   8 #include "base/callback.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "base/message_loop/message_loop.h"
  12 #include "ipc/ipc_export.h"
  13 #include "third_party/mojo/src/mojo/public/c/system/types.h"
  14
  15 namespace IPC {
  16 namespace internal {
  17
  18 // |AsyncHandleWaiter| waits on a mojo handle asynchronously and
  19 // invokes the given |callback| through |runner| when it is signaled.
  20 //  * To start waiting, the client must call |AsyncHandleWaiter::Wait()|.
  21 //    The client can call |Wait()| again once it is signaled and
  22 //    the |callback| is invoked.
  23 //  * To cancel waiting, delete the instance.
  24 //
  25 // |AsyncHandleWaiter| must be created, used and deleted only from the IO
  26 // |thread.
  27 class IPC_MOJO_EXPORT AsyncHandleWaiter {
  28  public:
  29   class Context;
  30
  31   explicit AsyncHandleWaiter(base::Callback<void(MojoResult)> callback);
  32   ~AsyncHandleWaiter();
  33
  34   MojoResult Wait(MojoHandle handle, MojoHandleSignals signals);
  35
  36   base::MessageLoopForIO::IOObserver* GetIOObserverForTest();
  37   base::Callback<void(MojoResult)> GetWaitCallbackForTest();
  38
  39  private:
  40   void InvokeCallback(MojoResult result);
  41
  42   scoped_refptr<Context> context_;
  43   base::Callback<void(MojoResult)> callback_;
  44   base::WeakPtrFactory<AsyncHandleWaiter> weak_factory_;
  45
  46   DISALLOW_COPY_AND_ASSIGN(AsyncHandleWaiter);
  47 };
  48
  49 }  // namespace internal
  50 }  // namespace IPC
  51
  52 #endif  // IPC_MOJO_ASYNC_HANDLE_WAITER_H_