Gr_msg_queue

On Thu, Jan 17, 2008 at 03:19:21PM -0500, Tim O’Shea wrote:

Hi Eric,

I have a gnuradio question, I posted this to the list but I don’t think it
was accepted.

Sorry, you have to post from a subscribed address. We don’t generate
an automatic response since several RBL’s black list us when we do…
http://gnuradio.org/trac/wiki/MailingLists

I have a flow graph which diverges down several pathways, and ends in
several separate gr_msg_queue’s, my initial design was to have one python
thread running as a handler for each queue,
so each handler process would sit on delete_head() until a new item arrived.

However it seems that if any more than a single python thread is using
delete_head() at one time, random memory access crashes seem to occur.

Do you have a simple test case that reproduces it?
If it’s our bug we should fix it.

Is there a clean way to block on multiple queues currently in svn ?

Not right now. However you may be able to use a loop that includes

m0 = msgq0.delete_head_nowait()
m1 = msgq1.delete_head_nowait()

time.sleep(0.010)

or something similar

I saw reference to a message passing interface of some sort upcoming,
but I assume this is not currently available ?

Not yet ready for prime time.

Thanks,
-Tim

Eric