The test consists of two parts:
- A tester that tries to trigger wrong states of work queue
- A verifier that checks whether the wqueue is still working properly
The tester is trying to queue and cancel work several times with
priority lower/same/higher than the work queue.
Most wrong cases are likely to happen with high priority like:
- If `cancel` never decreases semcount, the count may keep growing
and finally overflow
- If `cancel` is decreasing semcount too much, the `work_thread` may
be waken up less times than expected
The lower/same priority testers are just added for covering other
unexpected situations.
The verifier is trying to queue some works and check they are called as
expected:
- Frist queue a 'sleep' worker, to let a work queue thread be in busy
status and not waiting on sem, while other work queue thread(s) (if
any) still waiting for sem. If sem is in wrong state, it may cause
wrong behavior in either thread waiting/not waiting on the sem.
- Then queue a few count works, if the work queue(s) are still working
properly, these works should finally be all called once.
Signed-off-by: Zhe Weng <wengzhe@xiaomi.com>
