gecko/ipc/glue/SyncChannel.h

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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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 * The Original Code is Mozilla Plugin App.
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 * The Initial Developer of the Original Code is
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 * the Initial Developer. All Rights Reserved.
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#ifndef ipc_glue_SyncChannel_h
#define ipc_glue_SyncChannel_h 1

#include "mozilla/ipc/AsyncChannel.h"

namespace mozilla {
namespace ipc {
//-----------------------------------------------------------------------------

class SyncChannel : public AsyncChannel
{
protected:
    typedef uint16 MessageId;

public:
    class /*NS_INTERFACE_CLASS*/ SyncListener : 
        public AsyncChannel::AsyncListener
    {
    public:
        virtual ~SyncListener() { }

        virtual void OnChannelClose() = 0;
        virtual void OnChannelError() = 0;
        virtual Result OnMessageReceived(const Message& aMessage) = 0;
        virtual Result OnMessageReceived(const Message& aMessage,
                                         Message*& aReply) = 0;
    };

    SyncChannel(SyncListener* aListener);
    virtual ~SyncChannel();

    bool Send(Message* msg) {
        return AsyncChannel::Send(msg);
    }

    // Synchronously send |msg| (i.e., wait for |reply|)
    bool Send(Message* msg, Message* reply);

    // Override the AsyncChannel handler so we can dispatch sync messages
    NS_OVERRIDE virtual void OnMessageReceived(const Message& msg);
    NS_OVERRIDE virtual void OnChannelError();

    static bool IsPumpingMessages() {
        return sIsPumpingMessages;
    }
    static void SetIsPumpingMessages(bool aIsPumping) {
        sIsPumpingMessages = aIsPumping;
    }

protected:
    // Executed on the worker thread
    bool ProcessingSyncMessage() {
        return mProcessingSyncMessage;
    }

    void OnDispatchMessage(const Message& aMsg);
    void WaitForNotify();

    // Executed on the IO thread.
    void OnSendReply(Message* msg);
    void NotifyWorkerThread();

    // On both
    bool AwaitingSyncReply() {
        mMutex.AssertCurrentThreadOwns();
        return mPendingReply != 0;
    }

    MessageId mPendingReply;
    bool mProcessingSyncMessage;
    Message mRecvd;

    static bool sIsPumpingMessages;
};


} // namespace ipc
} // namespace mozilla
#endif  // ifndef ipc_glue_SyncChannel_h