[Discuss-gnuradio] problems in locking and unlocking the flow-graph

hi,
I am designing a transmitter which needs to transmit two different types , tone (of 1k frequency) and data (2k & 3k frequency).Both of them take user input, does processing and produce output on sound card of the laptop (am not using usrp).

I have implemented this all in a single flow graph and used lock and unlock to reconfigure the flow-graph.But it gets to a hanging state and looks like it is waiting for something in queue. I did try to use gr.message(1) before locking , which  locked and unlocked the flow-graph but the problem is that after using gr.message(1), self.src  does not get further data from the queue and without using it, it is stucked.

plz find some way out for me to transmit tone and data as required.




 class tx_graph(gr.top_block):

    def __init__(self):
        gr.top_block.__init__(self)
      
   
        self.src = gr.message_source(gr.sizeof_char, msgq_limit)
       
    #
    #  tone_blocks                            // tone processing blocks here
    #


    #
    #  data_blocks                            // data processing blocks here
    #

    self.sink = audio.sink(audio_rate,"plughw:0,0")
    self.connect(self.src,//data_blocks//,self.sink)    # assume that initially data is being transmitted
   
    def tone_transmit(self):
    self.lock()
    self.disconnect(self.src,//data_blocks//,self.sink)
    self.connect(self.src,//tone_blocks//,self.sink)
    self.unlock()

def main():
   
   fg=tx_graph()
   fg.start() 
      
   
          
   
    while True :       
        // assume first only data is being tranmitted
                    
   
            try:
           
           
               
   
            message = raw_input("Enter a message to transmit (Ctrl-D to exit): ")
                    msg64 = base64.standard_b64encode(message)
                    print "Encoding message= %s to base64= %s" % (message,msg64)
   
                    payload = clock_sync+sync+encode_6b_8b(msg64)+stop_sync
                    pkt = struct.pack('%iB' % (len(payload)),*payload)
   
                    msg = gr.message_from_string(pkt)
   
                    fg.src.msgq().insert_tail(msg)
           
            except EOFError:
                print "\nExiting."
                fg.src.msgq().insert_tail(gr.message(1))
                fg.wait()
       
    // assume now only tone is being transmitted

               
   
            try:
            fg.tone_transmit()                      
                    message = raw_input(" transmit a 5ms tone (Ctrl-D to exit): ")
                pkt = struct.pack('B', 0xff)
   
                    msg = gr.message_from_string(pkt)
                    fg.src.msgq().insert_tail(msg)
            
            except EOFError:
                print "\nExiting."
                fg.src.msgq().insert_tail(gr.message(1))
                fg.wait()

       


if __name__ == '__main__':        # main python entry here
    try:
        main()
    except KeyboardInterrupt:
        pass       
   
   

--
Niaz Ahmed

"We are always more anxious to be distinguished for a talent which we do not possess, than to be praised for the fifteen which we do possess"    :  Mark Twain