summaryrefslogtreecommitdiff
path: root/ipc/ipc_sync_message_filter.cc
diff options
context:
space:
mode:
Diffstat (limited to 'ipc/ipc_sync_message_filter.cc')
-rw-r--r--ipc/ipc_sync_message_filter.cc127
1 files changed, 127 insertions, 0 deletions
diff --git a/ipc/ipc_sync_message_filter.cc b/ipc/ipc_sync_message_filter.cc
new file mode 100644
index 0000000..cffbaa6
--- /dev/null
+++ b/ipc/ipc_sync_message_filter.cc
@@ -0,0 +1,127 @@
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ipc/ipc_sync_message_filter.h"
+
+#include "base/logging.h"
+#include "base/message_loop.h"
+#include "base/synchronization/waitable_event.h"
+#include "ipc/ipc_sync_message.h"
+
+namespace IPC {
+
+SyncMessageFilter::SyncMessageFilter(base::WaitableEvent* shutdown_event)
+ : channel_(NULL),
+ listener_loop_(MessageLoop::current()),
+ io_loop_(NULL),
+ shutdown_event_(shutdown_event) {
+}
+
+SyncMessageFilter::~SyncMessageFilter() {
+}
+
+bool SyncMessageFilter::Send(Message* message) {
+ {
+ base::AutoLock auto_lock(lock_);
+ if (!io_loop_) {
+ delete message;
+ return false;
+ }
+ }
+
+ if (!message->is_sync()) {
+ io_loop_->PostTask(
+ FROM_HERE,
+ NewRunnableMethod(this, &SyncMessageFilter::SendOnIOThread, message));
+ return true;
+ }
+
+ base::WaitableEvent done_event(true, false);
+ PendingSyncMsg pending_message(
+ SyncMessage::GetMessageId(*message),
+ reinterpret_cast<SyncMessage*>(message)->GetReplyDeserializer(),
+ &done_event);
+
+ {
+ base::AutoLock auto_lock(lock_);
+ // Can't use this class on the main thread or else it can lead to deadlocks.
+ // Also by definition, can't use this on IO thread since we're blocking it.
+ DCHECK(MessageLoop::current() != listener_loop_);
+ DCHECK(MessageLoop::current() != io_loop_);
+ pending_sync_messages_.insert(&pending_message);
+ }
+
+ io_loop_->PostTask(
+ FROM_HERE,
+ NewRunnableMethod(this, &SyncMessageFilter::SendOnIOThread, message));
+
+ base::WaitableEvent* events[2] = { shutdown_event_, &done_event };
+ base::WaitableEvent::WaitMany(events, 2);
+
+ {
+ base::AutoLock auto_lock(lock_);
+ delete pending_message.deserializer;
+ pending_sync_messages_.erase(&pending_message);
+ }
+
+ return pending_message.send_result;
+}
+
+void SyncMessageFilter::SendOnIOThread(Message* message) {
+ if (channel_) {
+ channel_->Send(message);
+ return;
+ }
+
+ if (message->is_sync()) {
+ // We don't know which thread sent it, but it doesn't matter, just signal
+ // them all.
+ SignalAllEvents();
+ }
+
+ delete message;
+}
+
+void SyncMessageFilter::SignalAllEvents() {
+ base::AutoLock auto_lock(lock_);
+ for (PendingSyncMessages::iterator iter = pending_sync_messages_.begin();
+ iter != pending_sync_messages_.end(); ++iter) {
+ (*iter)->done_event->Signal();
+ }
+}
+
+void SyncMessageFilter::OnFilterAdded(Channel* channel) {
+ channel_ = channel;
+ base::AutoLock auto_lock(lock_);
+ io_loop_ = MessageLoop::current();
+}
+
+void SyncMessageFilter::OnChannelError() {
+ channel_ = NULL;
+ SignalAllEvents();
+}
+
+void SyncMessageFilter::OnChannelClosing() {
+ channel_ = NULL;
+ SignalAllEvents();
+}
+
+bool SyncMessageFilter::OnMessageReceived(const Message& message) {
+ base::AutoLock auto_lock(lock_);
+ for (PendingSyncMessages::iterator iter = pending_sync_messages_.begin();
+ iter != pending_sync_messages_.end(); ++iter) {
+ if (SyncMessage::IsMessageReplyTo(message, (*iter)->id)) {
+ if (!message.is_reply_error()) {
+ (*iter)->send_result =
+ (*iter)->deserializer->SerializeOutputParameters(message);
+ }
+ (*iter)->done_event->Signal();
+ return true;
+ }
+ }
+
+ return false;
+}
+
+} // namespace IPC