Cleanup - remove ModuleLocalThreadAdapter.

ppapi/proxy/ppb_flash_proxy.cc

Index: ppapi/proxy/ppb_flash_proxy.cc
===================================================================
--- ppapi/proxy/ppb_flash_proxy.cc	(revision 140787)
+++ ppapi/proxy/ppb_flash_proxy.cc	(working copy)
@@ -62,313 +62,6 @@
   return out_handle;
 }
 
-// ModuleLocalThreadAdapter ----------------------------------------------------
-// TODO(yzshen): Refactor to use IPC::SyncMessageFilter.
-class ModuleLocalThreadAdapter
-    : public base::RefCountedThreadSafe<ModuleLocalThreadAdapter> {
-  class Filter;
- public:
-  ModuleLocalThreadAdapter();
-
-  void AddInstanceRouting(PP_Instance instance, Dispatcher* dispatcher);
-  void ClearInstanceRouting(PP_Instance instance);
-  void ClearFilter(Dispatcher* dispatcher, Filter* filter);
-
-  bool OnModuleLocalMessageReceived(const IPC::Message& msg);
-
-  // Called on the I/O thread when the channel is being destroyed and the
-  // given message will never be issued a reply.
-  void OnModuleLocalMessageFailed(int message_id);
-
-  bool Send(PP_Instance instance, IPC::Message* msg);
-
- private:
-  class Filter : public IPC::ChannelProxy::MessageFilter {
-   public:
-    explicit Filter(Dispatcher* dispatcher);
-    ~Filter();
-
-    void Send(IPC::Message* msg);
-
-    virtual void OnFilterAdded(IPC::Channel* channel);
-    virtual void OnFilterRemoved();
-    virtual bool OnMessageReceived(const IPC::Message& message);
-
-   private:
-    // DO NOT DEREFERENCE! This is used only for tracking.
-    Dispatcher* dispatcher_;
-
-    IPC::Channel* channel_;
-
-    // Holds the IPC messages that were sent before the channel was connected.
-    // These will be sent ASAP.
-    std::vector<IPC::Message*> pre_connect_pending_messages_;
-
-    // Holds the IDs of the sync messages we're currently waiting on for this
-    // channel. This tracking allows us to cancel those requests if the
-    // remote process crashes and we're cleaning up this filter (without just
-    // deadlocking the waiting thread(s).
-    std::set<int> pending_requests_for_filter_;
-  };
-
-  void SendFromIOThread(Dispatcher* dispatcher, IPC::Message* msg);
-
-  // Internal version of OnModuleLocalMessageFailed which assumes the lock
-  // is already held.
-  void OnModuleLocalMessageFailedLocked(int message_id);
-
-  base::Lock lock_;
-
-  scoped_refptr<base::MessageLoopProxy> main_thread_;
-
-  // Will be NULL before an instance routing is added.
-  scoped_refptr<base::MessageLoopProxy> io_thread_;
-
-  typedef std::map<PP_Instance, Dispatcher*> InstanceToDispatcher;
-  InstanceToDispatcher instance_to_dispatcher_;
-
-  // The filters are owned by the channel.
-  typedef std::map<Dispatcher*, Filter*> DispatcherToFilter;
-  DispatcherToFilter dispatcher_to_filter_;
-
-  // Tracks all messages with currently waiting threads. This does not own
-  // the pointer, the pointer lifetime is managed by Send().
-  typedef std::map<int, IPC::PendingSyncMsg*> SyncRequestMap;
-  SyncRequestMap pending_sync_requests_;
-};
-
-ModuleLocalThreadAdapter* g_module_local_thread_adapter = NULL;
-
-ModuleLocalThreadAdapter::Filter::Filter(Dispatcher* dispatcher)
-    : dispatcher_(dispatcher), channel_(NULL) {
-}
-
-ModuleLocalThreadAdapter::Filter::~Filter() {
-}
-
-void ModuleLocalThreadAdapter::Filter::Send(IPC::Message* msg) {
-  if (channel_) {
-    int message_id = IPC::SyncMessage::GetMessageId(*msg);
-    if (channel_->Send(msg))
-      pending_requests_for_filter_.insert(message_id);
-    else  // Message lost, notify adapter so it can unblock.
-      g_module_local_thread_adapter->OnModuleLocalMessageFailed(message_id);
-  } else {
-    // No channel, save this message for when it's connected.
-    pre_connect_pending_messages_.push_back(msg);
-  }
-}
-
-void ModuleLocalThreadAdapter::Filter::OnFilterAdded(IPC::Channel* channel) {
-  DCHECK(!channel_);
-  channel_ = channel;
-
-  // Now that we have a channel, process all pending messages.
-  for (size_t i = 0; i < pre_connect_pending_messages_.size(); i++)
-    Send(pre_connect_pending_messages_[i]);
-  pre_connect_pending_messages_.clear();
-}
-
-void ModuleLocalThreadAdapter::Filter::OnFilterRemoved() {
-  DCHECK(channel_);
-  channel_ = NULL;
-  g_module_local_thread_adapter->ClearFilter(dispatcher_, this);
-
-  for (std::set<int>::iterator i = pending_requests_for_filter_.begin();
-       i != pending_requests_for_filter_.end(); ++i) {
-    g_module_local_thread_adapter->OnModuleLocalMessageFailed(*i);
-  }
-}
-
-bool ModuleLocalThreadAdapter::Filter::OnMessageReceived(
-    const IPC::Message& message) {
-  if (!message.is_reply() ||
-      message.routing_id() != API_ID_PPB_FLASH)
-    return false;
-
-  if (g_module_local_thread_adapter->OnModuleLocalMessageReceived(message)) {
-    // The message was consumed, this means we can remove the message ID from
-    // the list of messages this channel is waiting on.
-    pending_requests_for_filter_.erase(IPC::SyncMessage::GetMessageId(message));
-    return true;
-  }
-  return false;
-}
-
-ModuleLocalThreadAdapter::ModuleLocalThreadAdapter()
-    : main_thread_(base::MessageLoopProxy::current()) {
-}
-
-void ModuleLocalThreadAdapter::AddInstanceRouting(PP_Instance instance,
-                                                  Dispatcher* dispatcher) {
-  base::AutoLock lock(lock_);
-
-  // Now that we've had contact with a dispatcher, we can set up the IO thread.
-  DCHECK(main_thread_->BelongsToCurrentThread());
-  if (!io_thread_.get())
-    io_thread_ = dispatcher->GetIPCMessageLoop();
-
-  // Set up the instance -> dispatcher routing.
-  DCHECK(instance_to_dispatcher_.find(instance) ==
-         instance_to_dispatcher_.end());
-  instance_to_dispatcher_[instance] = dispatcher;
-
-  DispatcherToFilter::iterator found_filter =
-      dispatcher_to_filter_.find(dispatcher);
-  if (found_filter == dispatcher_to_filter_.end()) {
-    // Need to set up a filter for this dispatcher to intercept the messages.
-    Filter* filter = new Filter(dispatcher);
-    dispatcher_to_filter_[dispatcher] = filter;
-    dispatcher->AddIOThreadMessageFilter(filter);
-  }
-}
-
-void ModuleLocalThreadAdapter::ClearInstanceRouting(PP_Instance instance) {
-  // The dispatcher->filter mapping is cleaned up by ClearFilter which is
-  // initiated by the channel.
-  instance_to_dispatcher_.erase(instance);
-}
-
-void ModuleLocalThreadAdapter::ClearFilter(Dispatcher* dispatcher,
-                                           Filter* filter) {
-  // DANGER! Don't dereference the dispatcher, it's just used to identify
-  // which filter to remove. The dispatcher may not even exist any more.
-  //
-  // Since the dispatcher may be gone, there's a potential for ambiguity if
-  // another one is created on the main thread before this code runs on the
-  // I/O thread. So we check that the filter matches to avoid this rare case.
-  base::AutoLock lock(lock_);
-  if (dispatcher_to_filter_[dispatcher] == filter)
-    dispatcher_to_filter_.erase(dispatcher);
-}
-
-bool ModuleLocalThreadAdapter::OnModuleLocalMessageReceived(
-    const IPC::Message& msg) {
-  base::AutoLock lock(lock_);
-
-  int message_id = IPC::SyncMessage::GetMessageId(msg);
-  SyncRequestMap::iterator found = pending_sync_requests_.find(message_id);
-  if (found == pending_sync_requests_.end()) {
-    // Not waiting for this event. This will happen for sync messages to the
-    // main thread which use the "regular" sync channel code path.
-    return false;
-  }
-
-  IPC::PendingSyncMsg& info = *found->second;
-
-  if (!msg.is_reply_error())
-    info.deserializer->SerializeOutputParameters(msg);
-  info.done_event->Signal();
-  return true;
-}
-
-void ModuleLocalThreadAdapter::OnModuleLocalMessageFailed(int message_id) {
-  base::AutoLock lock(lock_);
-  OnModuleLocalMessageFailedLocked(message_id);
-}
-
-bool ModuleLocalThreadAdapter::Send(PP_Instance instance, IPC::Message* msg) {
-  // Compute the dispatcher corresponding to this message.
-  Dispatcher* dispatcher = NULL;
-  {
-    base::AutoLock lock(lock_);
-    InstanceToDispatcher::iterator found =
-        instance_to_dispatcher_.find(instance);
-    if (found == instance_to_dispatcher_.end()) {
-      NOTREACHED();
-      delete msg;
-      return false;
-    }
-    dispatcher = found->second;
-  }
-
-  if (main_thread_->BelongsToCurrentThread()) {
-    // Easy case: We're on the same thread as the dispatcher, so we don't need
-    // a lock to access it, and we can just use the normal sync channel stuff
-    // to handle the message. Actually, we MUST use the normal sync channel
-    // stuff since there may be incoming sync messages that need processing.
-    // The code below doesn't handle any nested message loops.
-    return dispatcher->Send(msg);
-  }
-
-  // Background thread case
-  // ----------------------
-  //  1. Generate tracking info, stick in pending_sync_messages_map.
-  //  2. Kick off the request. This is done on the I/O thread.
-  //  3. Filter on the I/O thread notices reply, writes the reply data and
-  //     signals the event. We block on the event while this is happening.
-  //  4. Remove tracking info.
-
-  // Generate the tracking info. and copied
-  IPC::SyncMessage* sync_msg = static_cast<IPC::SyncMessage*>(msg);
-  int message_id = IPC::SyncMessage::GetMessageId(*sync_msg);
-  base::WaitableEvent event(true, false);
-  scoped_ptr<IPC::MessageReplyDeserializer> deserializer(
-      sync_msg->GetReplyDeserializer());  // We own this pointer once retrieved.
-  IPC::PendingSyncMsg info(message_id, deserializer.get(), &event);
-
-  // Add the tracking information to our map.
-  {
-    base::AutoLock lock(lock_);
-    pending_sync_requests_[message_id] = &info;
-  }
-
-  // This is a bit dangerous. We use the dispatcher pointer as the routing
-  // ID for this message. While we don't dereference it, there is an
-  // exceedingly remote possibility that while this is going to the background
-  // thread the connection will be shut down and a new one will be created with
-  // a dispatcher at the same address. It could potentially get sent to a
-  // random place, but it should actually still work (since the Flash file
-  // operations are global).
-  io_thread_->PostTask(FROM_HERE,
-      base::Bind(&ModuleLocalThreadAdapter::SendFromIOThread, this,
-                 dispatcher, msg));
-
-  // Now we block the current thread waiting for the reply.
-  event.Wait();
-
-  {
-    // Clear our tracking info for this message now that we're done.
-    base::AutoLock lock(lock_);
-    DCHECK(pending_sync_requests_.find(message_id) !=
-           pending_sync_requests_.end());
-    pending_sync_requests_.erase(message_id);
-  }
-
-  return true;
-}
-
-void ModuleLocalThreadAdapter::SendFromIOThread(Dispatcher* dispatcher,
-                                                IPC::Message* msg) {
-  // DO NOT DEREFERENCE DISPATCHER. Used as a lookup only.
-  base::AutoLock lock(lock_);
-  DispatcherToFilter::iterator found = dispatcher_to_filter_.find(dispatcher);
-
-  // The dispatcher could have been destroyed by the time we got here since
-  // we're on another thread. Need to unblock the caller.
-  if (found == dispatcher_to_filter_.end()) {
-    OnModuleLocalMessageFailedLocked(IPC::SyncMessage::GetMessageId(*msg));
-    delete msg;
-    return;
-  }
-
-  // Takes ownership of pointer.
-  found->second->Send(msg);
-}
-
-void ModuleLocalThreadAdapter::OnModuleLocalMessageFailedLocked(
-    int message_id) {
-  lock_.AssertAcquired();
-
-  // Unblock the thread waiting for the message that will never come.
-  SyncRequestMap::iterator found = pending_sync_requests_.find(message_id);
-  if (found == pending_sync_requests_.end()) {
-    NOTREACHED();
-    return;
-  }
-  found->second->done_event->Signal();
-}
-
 void InvokePrinting(PP_Instance instance) {
   PluginDispatcher* dispatcher = PluginDispatcher::GetForInstance(instance);
   if (dispatcher) {
@@ -659,23 +352,10 @@
 }
 
 bool PPB_Flash_Proxy::CreateThreadAdapterForInstance(PP_Instance instance) {
-  if (!g_module_local_thread_adapter) {
-    g_module_local_thread_adapter = new ModuleLocalThreadAdapter();
-    g_module_local_thread_adapter->AddRef();  // Leaked, this object is global.
-  }
-
-  PluginDispatcher* dispatcher = PluginDispatcher::GetForInstance(instance);
-  if (!dispatcher) {
-    NOTREACHED();
-    return false;
-  }
-  g_module_local_thread_adapter->AddInstanceRouting(instance, dispatcher);
   return true;
 }
 
 void PPB_Flash_Proxy::ClearThreadAdapterForInstance(PP_Instance instance) {
-  if (g_module_local_thread_adapter)
-    g_module_local_thread_adapter->ClearInstanceRouting(instance);
 }
 
 int32_t PPB_Flash_Proxy::OpenFile(PP_Instance,