#!/usr/bin/env python
# -*- coding: utf-8 -*-
# 
# Author: Piotr Krysik <address@hidden>

#Program presenting potential problem caused by message passing done
#from Python. The program should exit after sending the message - however this doesn't happen.

from gnuradio import gr
import pmt

class test_msg_source(gr.basic_block):
    def __init__(self):
        gr.basic_block.__init__(self, name="test_msg_source", in_sig=[], out_sig=[])
        self.message_port_register_out(pmt.intern("msgs"))

    def send_msg(self):
        msg_ppm = pmt.from_double(0.0)
        self.message_port_pub(pmt.intern("msgs"), msg_ppm)


class test_msg_sink(gr.basic_block):
    def __init__(self):
        gr.basic_block.__init__(self, name="test_msg_sink", in_sig=[], out_sig=[])
        self.message_port_register_in(pmt.intern("msgs"))
        self.set_msg_handler(pmt.intern("msgs"), self.process_msg)

    def process_msg(self, msg):
        print "Received message:", msg


class test_flowgraph(gr.top_block):
    def __init__(self):
        gr.top_block.__init__(self, "test_flograph")
        self.msg_source = test_msg_source()
        self.msg_sink = test_msg_sink()        
        self.msg_connect((self.msg_source, 'msgs'), (self.msg_sink, 'msgs'))
    
    def trigger_message_transmission(self):
        self.msg_source.send_msg()


if __name__ == '__main__':
    tb = test_flowgraph()
    tb.start()
    tb.trigger_message_transmission() 
    tb.wait()