"Can't obtain network semaphore"

[Steve Holle]

I have a suspect in the investigation of this problem and I would like to 
run it by you guys to see what you think.

To break when the _Thread_Executing->Wait.return_code gets set instead of 
when it finally gets checked, I first broke on the panic message and copied 
down the address in the _Thread_Executing pointer and restarted the 
program.  I then dereferenced the pointer as follows :
         ((Thread_Control_struct *)0x600600)->Wait.return_code
I set a hardware watchpoint on the resulting dereference and then set a 
condition on that hardware watchpoint of :
         ((Thread_Control_struct *)0x600600)->Wait.return_code==4
I then started the program and it eventually broke on coremsgseize.c:136 
which is the return from the _CORE_message_queue_Seize routine.  On line 
123 of that routine, the following lines of code is executed :
         executing->Wait.return_code = 
CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED_NOWAIT ;
         return ;
The CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED_NOWAIT enum results in a 4 in the 
executing->Wait.return_code and executing at this point resolves to an 
address of 0x600600.

The backtrace at this point is as follows :
         #3      0x000677f6      in streaming_audio_dma_interrupt() at 
ConfigDSPInterrupts.cc:33
         #2      0x0004410c      in StreamingAudioNetworkToCodecGetData() 
at StreamingAudio.cc:139
         #1      0x00117aea      in rtems_message_queue_receive () at 
msgreceive.c:88
         #0      0x0012ab4c      in _Core_message_queue_Seize () at 
coremsgseize.c:136

Obviously, the rtems_message_queue_receive function is being called from 
and interrupt.  The interrupt is set up, as far as I can discern, in a 
conforming manner, using rtems_interrupt_catch.  It is entirely possible 
that I am misusing the rtems_message_queue_receive function incorrectly 
from an interrupt.

Is it legal to call rtems_message_queue_receive from an interrupt?
Are there any special precautions in setting up a queue to be used within 
an interrupt?

If anyone would like screenshots or listing of any sections of my code, 
please let me know and I will email them to you.

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