C++ MessageID::isSync方法代码示例

void Connection::dispatchSyncMessage(MessageID messageID, ArgumentDecoder* arguments)
{
    ASSERT(messageID.isSync());

    // Decode the sync request ID.
    uint64_t syncRequestID = 0;

    if (!arguments->decodeUInt64(syncRequestID) || !syncRequestID) {
        // We received an invalid sync message.
        arguments->markInvalid();
        return;
    }

    // Create our reply encoder.
    ArgumentEncoder* replyEncoder = ArgumentEncoder::create(syncRequestID).leakPtr();
    
    // Hand off both the decoder and encoder to the client..
    SyncReplyMode syncReplyMode = m_client->didReceiveSyncMessage(this, messageID, arguments, replyEncoder);

    // FIXME: If the message was invalid, we should send back a SyncMessageError.
    ASSERT(!arguments->isInvalid());

    if (syncReplyMode == ManualReply) {
        // The client will take ownership of the reply encoder and send it at some point in the future.
        // We won't do anything here.
        return;
    }

    // Send the reply.
    sendSyncReply(replyEncoder);
}

void Connection::processIncomingMessage(MessageID messageID, PassOwnPtr<ArgumentDecoder> arguments)
{
    // Check if this is a sync reply.
    if (messageID == MessageID(CoreIPCMessage::SyncMessageReply)) {
        MutexLocker locker(m_syncReplyStateMutex);
        ASSERT(!m_pendingSyncReplies.isEmpty());

        PendingSyncReply& pendingSyncReply = m_pendingSyncReplies.last();
        ASSERT(pendingSyncReply.syncRequestID == arguments->destinationID());

        pendingSyncReply.replyDecoder = arguments.leakPtr();
        pendingSyncReply.didReceiveReply = true;

        m_waitForSyncReplySemaphore.signal();
        return;
    }

    // Check if this is a sync message. If it is, and we're waiting for a sync reply this message
    // needs to be dispatched. If we don't we'll end up with a deadlock where both sync message senders are
    // stuck waiting for a reply.
    if (messageID.isSync()) {
        MutexLocker locker(m_syncReplyStateMutex);
        if (!m_pendingSyncReplies.isEmpty()) {
            m_syncMessagesReceivedWhileWaitingForSyncReply.append(IncomingMessage(messageID, arguments));

            // The message has been added, now wake up the client thread.
            m_waitForSyncReplySemaphore.signal();
            return;
        }
    }
        
    // Check if we're waiting for this message.
    {
        MutexLocker locker(m_waitForMessageMutex);
        
        HashMap<std::pair<unsigned, uint64_t>, ArgumentDecoder*>::iterator it = m_waitForMessageMap.find(std::make_pair(messageID.toInt(), arguments->destinationID()));
        if (it != m_waitForMessageMap.end()) {
            it->second = arguments.leakPtr();
        
            m_waitForMessageCondition.signal();
            return;
        }
    }

    MutexLocker locker(m_incomingMessagesLock);
    m_incomingMessages.append(IncomingMessage(messageID, arguments));

    m_clientRunLoop->scheduleWork(WorkItem::create(this, &Connection::dispatchMessages));
}