ppapi/shared_impl/ppb_message_loop_shared.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 PPAPI_SHARED_IMPL_PPB_MESSAGE_LOOP_SHARED_H_
   6 #define PPAPI_SHARED_IMPL_PPB_MESSAGE_LOOP_SHARED_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/callback_forward.h"
  10 #include "base/location.h"
  11 #include "ppapi/c/pp_instance.h"
  12 #include "ppapi/shared_impl/ppapi_shared_export.h"
  13 #include "ppapi/shared_impl/resource.h"
  14 #include "ppapi/thunk/ppb_message_loop_api.h"
  15
  16 namespace tracked_objects {
  17 class Location;
  18 }
  19
  20 namespace ppapi {
  21
  22 // MessageLoopShared doesn't really do anything interesting. It exists so that
  23 // shared code (in particular, TrackedCallback) can keep a pointer to a
  24 // MessageLoop resource. In the host side, there is not a concrete class that
  25 // implements this. So pointers to MessageLoopShared can only really be valid
  26 // on the plugin side.
  27 class PPAPI_SHARED_EXPORT MessageLoopShared
  28     : public Resource,
  29       public thunk::PPB_MessageLoop_API {
  30  public:
  31   explicit MessageLoopShared(PP_Instance instance);
  32   // Construct the one MessageLoopShared for the main thread. This must be
  33   // invoked on the main thread.
  34   struct ForMainThread {};
  35   explicit MessageLoopShared(ForMainThread);
  36   virtual ~MessageLoopShared();
  37
  38   // Handles posting to the message loop if there is one, or the pending queue
  39   // if there isn't.
  40   // NOTE: The given closure will be run *WITHOUT* acquiring the Proxy lock.
  41   //       This only makes sense for user code and completely thread-safe
  42   //       proxy operations (e.g., MessageLoop::QuitClosure).
  43   virtual void PostClosure(const tracked_objects::Location& from_here,
  44                            const base::Closure& closure,
  45                            int64 delay_ms) = 0;
  46
  47   DISALLOW_COPY_AND_ASSIGN(MessageLoopShared);
  48 };
  49
  50 }  // namespace ppapi
  51
  52 #endif  // PPAPI_SHARED_IMPL_PPB_MESSAGE_LOOP_SHARED_H_