rtems_message_queue_receive

[Steve Holle]

Follow up :
Is it possible that I am hogging the Message Manager by sending these 
messages?  I'm sending 256 bytes of data every 16mS.

At 09:52 AM 11/11/2004, Steve Holle wrote:
>Good catch about the interrupts.  I did find one interrupt that was a, 
>shall we say, non-conformist, and fixed it but I'm still having 
>problems.  Let me explain my problem with a little more detail.
>
>Our system has two main threads, one running our fltk based GUI and the 
>other running everything else.  We also have a number of threads running 
>network functions, such as telnet, ftp, and a webserver.  All this has 
>been running fine up to this point.
>
>I'm trying to add a data stream that comes from one of the DSP cards in 
>our system, streams data to a remote system over the network and receives 
>data back from the network for output to the DSP.  The data transfer is 
>initiated by an interrupt (conforming) generated by the DSP card which 
>passes the DSP-to-net data via a blocking rtems-queue in another 
>thread.  In the same interrupt, we are passing data from another 
>rtems-queue to the DSP.  The last queue is filled in a blocking RX queue.
>
>I've tried to fashion my code based on the telnet server that we have 
>running, a very simple one connection telnet app.
>
>If I comment out the code in the interrupt that sends the data to the 
>queue that is read in the blocked thread waiting to transmit over the 
>network, everything works fine.  As soon as I try to enable the queue 
>write, the GUI locks up.  What I mean by that is that it becomes 
>unresponsive and actually does not complete a screen refresh that is in 
>progress.
>
>I've read the GUI thread status from the streaming server with an assert 
>if it is ever inactive and it always reads back active.  My other main 
>thread seems to run fine.  I can communicate with it via a serial terminal 
>and the response is snappy.
>
>When we run the BMD, before the call in the interrupt we are able to break 
>in the main while loop of the GUI.  After the call, the program will no 
>longer break inside the GUI main while loop.
>
>I'm not sure how to proceed from here.  Any ideas?
>
>At 06:22 PM 11/10/2004, Ian Caddy wrote:
>>Hi Steve,
>>
>>rtems_message_queue_send is allowed from conforming interrupts.  In other 
>>words interrupts that use rtems_interrupt_catch to establish them.
>>
>>It is also important to note that any lower priority interrupt than the 
>>one where you are calling RTEMS functions must also be conforming interrupts.
>>
>>When you say hangs, do you mean the processor stops (I think from memory 
>>you are using a Coldfire?) you should be able to put a BDM onto your 
>>system with gdb and run it normally until it stops.  Then get control 
>>back in gdb and it should indicate where the more than likely bus error 
>>is, to see if you can narrow down your problem.
>>
>>I hope this helps,
>>
>>Ian Caddy
>>
>>
>>Steve Holle wrote:
>>>I have what is probably a basic question about 
>>>rtems_message_queue_receive.  If I am using rtems_message_queue_receive 
>>>with the RTEMS_WAIT attribute set in a server thread, can I fill the 
>>>thread using rtems_message_queue_send in an interrupt?  It seems almost 
>>>as if the rtems_message_queue_send is being blocked by the 
>>>rtems_message_queue_receive and my code hangs in the interrupt.
>>>On the other hand, I may be doing something really stupid ;-}
>>>Steve Holle
>>>Link Communications, Inc.
>>>1035 Cerise Rd.
>>>Billings, MT  59101
>>>sholle at link-comm.com
>>
>>Steve Holle
>>Link Communications, Inc.
>>1035 Cerise Rd.
>>Billings, MT  59101
>>sholle at link-comm.com

Steve Holle
Link Communications, Inc.
1035 Cerise Rd.
Billings, MT  59101
sholle at link-comm.com