pthreadpool_pipe: Implement EBUSY for _destroy
Restore EBUSY on pthreadpool_pipe_destroy.
We need to count jobs in pthreadpool_pipe so that pthreadpool can exit with
active jobs. Unfortunately this makes pthreadpool_pipe_add_job non-threadsafe.
We could add mutexes around "num_jobs", but this would mean another set of
pthread_atfork functions. As we don't use threaded pthreadpool_pipe_add_job
except in the tests, just remove the tests...
Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>