ppapi/proxy/message_handler.h

   1 // Copyright 2014 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_PROXY_MESSAGE_HANDLER_H_
   6 #define PPAPI_PROXY_MESSAGE_HANDLER_H_
   7
   8 #include "base/memory/ref_counted.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "ppapi/c/pp_resource.h"
  11 #include "ppapi/c/ppp_message_handler.h"
  12 #include "ppapi/proxy/ppapi_proxy_export.h"
  13
  14 namespace IPC {
  15 class Message;
  16 }
  17
  18 namespace ppapi {
  19
  20 class ScopedPPVar;
  21
  22 namespace proxy {
  23
  24 class MessageLoopResource;
  25
  26 // MessageHandler wraps a PPP_MessageHandler to encapsulate calling methods
  27 // on the right thread and calling the Destroy function when this
  28 // MessageHandler is destroyed.
  29 class PPAPI_PROXY_EXPORT MessageHandler {
  30  public:
  31   // Create a MessageHandler. If any parameters are invalid, it will return a
  32   // null scoped_ptr and set |*error| appropriately.
  33   // |handler_if| is the struct of function pointers we will invoke. All of
  34   //              the function pointers within must be valid, or we fail
  35   //              with PP_ERROR_BADARGUMENT.
  36   // |user_data| is a pointer provided by the plugin that we pass back when we
  37   //             call functions in |handler_if|.
  38   // |message_loop| is the message loop where we will invoke functions in
  39   //                |handler_if|. Must not be the main thread message loop,
  40   //                to try to force the plugin to not over-subscribe the main
  41   //                thread. If it's the main thread loop, |error| will be set
  42   //                to PP_ERROR_WRONGTHREAD.
  43   // |error| is an out-param that will be set on failure.
  44   static scoped_ptr<MessageHandler> Create(
  45       PP_Instance instance,
  46       const PPP_MessageHandler_0_2* handler_if,
  47       void* user_data,
  48       PP_Resource message_loop,
  49       int32_t* error);
  50   ~MessageHandler();
  51
  52   bool LoopIsValid() const;
  53
  54   void HandleMessage(ScopedPPVar var);
  55   void HandleBlockingMessage(ScopedPPVar var,
  56                              scoped_ptr<IPC::Message> reply_msg);
  57
  58  private:
  59   MessageHandler(PP_Instance instance,
  60                  const PPP_MessageHandler_0_2* handler_if,
  61                  void* user_data,
  62                  scoped_refptr<MessageLoopResource> message_loop);
  63   PP_Instance instance_;
  64   const PPP_MessageHandler_0_2* handler_if_;
  65   void* user_data_;
  66   scoped_refptr<MessageLoopResource> message_loop_;
  67
  68   DISALLOW_COPY_AND_ASSIGN(MessageHandler);
  69 };
  70
  71 }  // namespace proxy
  72 }  // namespace ppapi
  73
  74 #endif  // PPAPI_PROXY_MESSAGE_HANDLER_H_