Question about semaphores and threads

Marc CHALAND l4 at
Wed Jan 23 11:39:49 CET 2008

2008/1/22, Adam Lackorzynski <adam at>:
> The thread should exist, looking at the code path in the semaphore lib.
> The thread_id used for the prio-get is coming fron an ipc-wait so the
> thread should be there (in the sense there's a thread at all). The
> thread-lib might have some other state than ACTIVE for this thread.

OK, I agree and I understand :).

> If you look in the debugger, the thread is there and its state is fine?

This happens when we do heavy testing. The task has a standard
behavior : a manager thread and several worker threads. This message
happens on workers. As worker doesn't live long enough, it is diffult
for me to catch info about that threads. Perhaps, I should try to
modify semaphore and add a enter_kdebug() ?

> If it happens, is it a permanent error or just sporadic? Does it happen
> during some setup phase or after that when things have settled?

This happens only after several minutes of heavy testing and
sometimes. As we have only one testing infra on which problem occurs,
we will do more investigation after l4rm synchro valid.


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