I have found what seems to cause my problem. I have two threads, t1 and t2.
t1 has a priority level of 30, and t2 has a priority level of 5. I am using the native skin, so t1 has the higher priority. t2 is flashing an LED on my board every 40 ms, and t1 does nothing until I hit a key on the keyboard. When t1 activates, it does for(i=0; i<100000000; i++) which locks up my board for about 3 seconds. During this time, I expect my LED to stop flashing. However, the LED will flash a few times just once, at a rate of about 1 second. (Coincidentally, 1 second is the timing of another unrelated thread in the system.) At the start of my t1 thread, I use syslog (a system call) to log that the thread is created. This call is made once before the thread goes into its loop, waiting for a global variable to be set otherwise just calling rt_task_wait_period(). If I comment out my call to syslog, which again I state is NOT in the thread loop, this behavior goes away. It seems that once a syscall is made in a shadow thread, xenomai fails to have it behave in a true hard realtime fashion. It's as if the thread stays relaxed. Does this shed any light on the issue I have? Steven
