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// 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
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