Dan,
thanks for the info you provided; it was ver helpful!
I think I got the basic understanding of the message_source/sink.
I wrote my first toy code based on this:
The Tx queues 100 packets and the Rx waits until
it receives everything (broken into different number of packets)…
The Rx does not know when transmission ended
but I can check the total # of bytes received and it
coincides with that transmitted.
I hope I have not missed something big here.
I wanted to ask if there is a natural way for the code to exit
this kind of loop; so far I am doing it manually with contr-C
Thanks
Achilleas
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#!/usr/bin/env python
from gnuradio import gr
class my_graph(gr.flow_graph):
def init(self,rx_queue):
gr.flow_graph.init(self)
Qtx=20
src = gr.message_source(gr.sizeof_char,Qtx)
self.tx_queue = src.msgq()
dst = gr.message_sink(gr.sizeof_char,rx_queue,False)
self.connect (src, dst)
if name == ‘main’:
payload = ‘abcdefghijklmnopqrst’
Qrx=5
rx_queue = gr.msg_queue(Qrx)
fg=my_graph(rx_queue)
print 'Starting the graph'
fg.start()
i=1
j=1
imax=100 # max number of packets to Tx
tot=0 # counts number of received bytes
tx_done = False
while True:
# process Tx side
if not tx_done:
msg=gr.message_from_string(payload)
fg.tx_queue.insert_tail(msg)
print 'Just queued the ',i,' th packet'
i+=1
if i>imax:
tx_done = True
print 'Nothing to do at the Tx'
print 'Sending the EOF message'
eof_msg=gr.message(1)
fg.tx_queue.insert_tail(eof_msg)
#process Rx side
while not rx_queue.empty_p():
rmsg = rx_queue.delete_head()
tot+=rmsg.length()
print 'I got mail: ',j,rmsg.type(), rmsg.length(),