content/browser/renderer_host/java/java_bridge_channel_host.cc

   1 // Copyright (c) 2011 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 "content/browser/renderer_host/java/java_bridge_channel_host.h"
   6
   7 #include "base/atomicops.h"
   8 #include "base/lazy_instance.h"
   9 #include "base/strings/stringprintf.h"
  10 #include "base/synchronization/waitable_event.h"
  11 #include "content/common/java_bridge_messages.h"
  12
  13 using base::WaitableEvent;
  14
  15 namespace content {
  16 namespace {
  17 struct WaitableEventLazyInstanceTraits
  18     : public base::DefaultLazyInstanceTraits<WaitableEvent> {
  19   static WaitableEvent* New(void* instance) {
  20     // Use placement new to initialize our instance in our preallocated space.
  21     // The parenthesis is very important here to force POD type initialization.
  22     return new (instance) WaitableEvent(false, false);
  23   }
  24 };
  25 base::LazyInstance<WaitableEvent, WaitableEventLazyInstanceTraits> dummy_event =
  26     LAZY_INSTANCE_INITIALIZER;
  27
  28 base::subtle::AtomicWord g_last_id = 0;
  29 }
  30
  31 JavaBridgeChannelHost::~JavaBridgeChannelHost() {
  32 #if defined(OS_POSIX)
  33   if (channel_handle_.socket.fd > 0) {
  34     close(channel_handle_.socket.fd);
  35   }
  36 #endif
  37 }
  38
  39 JavaBridgeChannelHost* JavaBridgeChannelHost::GetJavaBridgeChannelHost(
  40     int renderer_id,
  41     base::MessageLoopProxy* ipc_message_loop) {
  42   std::string channel_name(base::StringPrintf("r%d.javabridge", renderer_id));
  43   // There's no need for a shutdown event here. If the browser is terminated
  44   // while the JavaBridgeChannelHost is blocked on a synchronous IPC call, the
  45   // renderer's shutdown event will cause the underlying channel to shut down,
  46   // thus terminating the IPC call.
  47   return static_cast<JavaBridgeChannelHost*>(NPChannelBase::GetChannel(
  48       channel_name,
  49       IPC::Channel::MODE_SERVER,
  50       ClassFactory,
  51       ipc_message_loop,
  52       true,
  53       dummy_event.Pointer()));
  54 }
  55
  56 int JavaBridgeChannelHost::ThreadsafeGenerateRouteID() {
  57   return base::subtle::NoBarrier_AtomicIncrement(&g_last_id, 1);
  58 }
  59
  60 int JavaBridgeChannelHost::GenerateRouteID() {
  61   return ThreadsafeGenerateRouteID();
  62 }
  63
  64 bool JavaBridgeChannelHost::Init(base::MessageLoopProxy* ipc_message_loop,
  65                                  bool create_pipe_now,
  66                                  WaitableEvent* shutdown_event) {
  67   if (!NPChannelBase::Init(ipc_message_loop, create_pipe_now, shutdown_event)) {
  68     return false;
  69   }
  70
  71   // Finish populating our ChannelHandle.
  72 #if defined(OS_POSIX)
  73   // We take control of the FD for all session between this host and
  74   // the corresponding renderers. We keep it open until this object
  75   // is deleted.
  76   channel_handle_.socket.fd = channel_->TakeClientFileDescriptor();
  77 #endif
  78
  79   return true;
  80 }
  81
  82 bool JavaBridgeChannelHost::OnControlMessageReceived(
  83     const IPC::Message& message) {
  84   bool handled = true;
  85   IPC_BEGIN_MESSAGE_MAP(JavaBridgeChannelHost, message)
  86     IPC_MESSAGE_HANDLER(JavaBridgeMsg_GenerateRouteID, OnGenerateRouteID)
  87   IPC_END_MESSAGE_MAP()
  88   return handled;
  89 }
  90
  91 void JavaBridgeChannelHost::OnGenerateRouteID(int* route_id) {
  92   *route_id = GenerateRouteID();
  93 }
  94
  95 }  // namespace content