public ChannelJni() 
{
      
        // we use static for now, it's easier on the C side.
        // Easy to change after we get everything working
}

 public int flush(Msg msg,
    MsgContext ep) throws IOException 
{
        ep.setNote( receivedNote, null );
        return OK;
}

 public String getChannelName() 
{
        return getName();
}

 public  void init() throws IOException 
{
        super.initNative("channel.jni:jni");
        if( apr==null ) return;
        // We'll be called from C. This deals with that.
        apr.addJkHandler( "channelJni", this );        
        log.info("JK: listening on channel.jni:jni" );
        if( next==null ) {
            if( nextName!=null ) 
                setNext( wEnv.getHandler( nextName ) );
            if( next==null )
                next=wEnv.getHandler( "dispatch" );
            if( next==null )
                next=wEnv.getHandler( "request" );
            if( log.isDebugEnabled() )
                log.debug("Setting default next " + next.getClass().getName());
        }
}

 public int invoke(Msg msg,
    MsgContext ep) throws IOException 
{
        if( apr==null ) return -1;
        long xEnv=ep.getJniEnv();
        long cEndpointP=ep.getJniContext();
        int type=ep.getType();
        if( log.isDebugEnabled() ) log.debug("ChannelJni.invoke: "  + ep + " " + type);
        switch( type ) {
        case JkHandler.HANDLE_RECEIVE_PACKET:
            return receive( msg, ep );
        case JkHandler.HANDLE_SEND_PACKET:
            return send( msg, ep );
        case JkHandler.HANDLE_FLUSH:
            return flush(msg, ep);
        }
        // Reset receivedNote. It'll be visible only after a SEND and before a receive.
        ep.setNote( receivedNote, null );
        // Default is FORWARD - called from C 
        try {
            // first, we need to get an endpoint. It should be
            // per/thread - and probably stored by the C side.
            if( log.isDebugEnabled() ) log.debug("Received request " + xEnv);
            // The endpoint will store the message pt.
            msg.processHeader();
            if( log.isTraceEnabled() ) msg.dump("Incoming msg ");
            int status= next.invoke(  msg, ep );
            if( log.isDebugEnabled() ) log.debug("after processCallbacks " + status);
            return status;
        } catch( Exception ex ) {
            ex.printStackTrace();
        }
        return 0;
}

Receive a packet from the C side. This is called from the C code using invocation, but only for the first packet - to avoid recursivity and thread problems. This may look strange, but seems the best solution for the problem ( the problem is that we don't have 'continuation' ). sendPacket will move the thread execution on the C side, and return when another packet is available. For packets that are one way it'll return after it is processed too ( having 2 threads is far more expensive ). Again, the goal is to be efficient and behave like all other Channels ( so the rest of the code can be shared ). Playing with java objects on C is extremely difficult to optimize and do right ( IMHO ), so we'll try to keep it simple - byte[] passing, the conversion done in java ( after we know the encoding and if anyone asks for it - same lazy behavior as in 3.3 ).

 public boolean isSameAddress(MsgContext ep) 
{
        return true;
}

 public int receive(Msg msg,
    MsgContext ep) throws IOException 
{
        Msg sentResponse=(Msg)ep.getNote( receivedNote );
        ep.setNote( receivedNote, null );
        if( sentResponse == null ) {
            if( log.isDebugEnabled() )
                log.debug("No send() prior to receive(), no data buffer");
            // No sent() was done prior to receive.
            msg.reset();
            msg.end();
            sentResponse = msg;
        }
        sentResponse.processHeader();
        if( log.isTraceEnabled() )
            sentResponse.dump("received response ");
        if( msg != sentResponse ) {
            log.error( "Error, in JNI mode the msg used for receive() must be identical with the one used for send()");
        }
        return 0;
}

Receives does nothing - send will put the response in the same buffer

 public  void registerRequest(Request req,
    MsgContext ep,
    int count) 
{
        // Not supported.
}

 public int send(Msg msg,
    MsgContext ep) throws IOException 
{
        ep.setNote( receivedNote, null );
        if( log.isDebugEnabled() ) log.debug("ChannelJni.send: "  +  msg );
        int rc=super.nativeDispatch( msg, ep, JK_HANDLE_JNI_DISPATCH, 0);
        // nativeDispatch will put the response in the same buffer.
        // Next receive() will just get it from there. Very tricky to do
        // things in one thread instead of 2.
        ep.setNote( receivedNote, msg );
        return rc;
}

Send the packet. XXX This will modify msg !!! We could use 2 packets, or sendAndReceive().