src/ppapi/host/resource_message_filter.cc

   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 #include "ppapi/host/resource_message_filter.h"
   6
   7 #include "base/bind.h"
   8 #include "base/message_loop/message_loop.h"
   9 #include "base/message_loop/message_loop_proxy.h"
  10 #include "base/task_runner.h"
  11 #include "ipc/ipc_message.h"
  12 #include "ppapi/c/pp_errors.h"
  13 #include "ppapi/host/ppapi_host.h"
  14 #include "ppapi/host/resource_host.h"
  15
  16 namespace ppapi {
  17 namespace host {
  18
  19 ResourceMessageFilter::ResourceMessageFilter()
  20     : reply_thread_message_loop_proxy_(
  21           base::MessageLoop::current()->message_loop_proxy()),
  22       resource_host_(NULL) {}
  23
  24 ResourceMessageFilter::ResourceMessageFilter(
  25     scoped_refptr<base::MessageLoopProxy> reply_thread_message_loop_proxy)
  26     : reply_thread_message_loop_proxy_(reply_thread_message_loop_proxy),
  27       resource_host_(NULL) {
  28 }
  29
  30 ResourceMessageFilter::~ResourceMessageFilter() {
  31 }
  32
  33 void ResourceMessageFilter::OnFilterAdded(ResourceHost* resource_host) {
  34   resource_host_ = resource_host;
  35 }
  36
  37 void ResourceMessageFilter::OnFilterDestroyed() {
  38   resource_host_ = NULL;
  39 }
  40
  41 bool ResourceMessageFilter::HandleMessage(const IPC::Message& msg,
  42                                           HostMessageContext* context) {
  43   scoped_refptr<base::TaskRunner> runner = OverrideTaskRunnerForMessage(msg);
  44   if (runner.get()) {
  45     if (runner->RunsTasksOnCurrentThread()) {
  46       DispatchMessage(msg, *context);
  47     } else {
  48       // TODO(raymes): We need to make a copy so the context can be used on
  49       // other threads. It would be better to have a thread-safe refcounted
  50       // context.
  51       HostMessageContext context_copy = *context;
  52       runner->PostTask(FROM_HERE, base::Bind(
  53           &ResourceMessageFilter::DispatchMessage, this, msg, context_copy));
  54     }
  55     return true;
  56   }
  57
  58   return false;
  59 }
  60
  61 void ResourceMessageFilter::SendReply(const ReplyMessageContext& context,
  62                                       const IPC::Message& msg) {
  63   if (!reply_thread_message_loop_proxy_->BelongsToCurrentThread()) {
  64     reply_thread_message_loop_proxy_->PostTask(FROM_HERE,
  65         base::Bind(&ResourceMessageFilter::SendReply, this, context, msg));
  66     return;
  67   }
  68   if (resource_host_)
  69     resource_host_->SendReply(context, msg);
  70 }
  71
  72 scoped_refptr<base::TaskRunner>
  73 ResourceMessageFilter::OverrideTaskRunnerForMessage(const IPC::Message& msg) {
  74   return NULL;
  75 }
  76
  77 void ResourceMessageFilter::DispatchMessage(const IPC::Message& msg,
  78                                             HostMessageContext context) {
  79   RunMessageHandlerAndReply(msg, &context);
  80 }
  81
  82 }  // namespace host
  83 }  // namespace ppapi