CVS commit: src/lib/libpthread

["Andrew Doran" <ad%netbsd.org@localhost>]

Module Name:    src
Committed By:   ad
Date:           Wed Jun  3 22:10:24 UTC 2020

Modified Files:
        src/lib/libpthread: pthread.c pthread_cond.c pthread_mutex.c

Log Message:
Deal with a couple of problems with threads being awoken early due to
timeouts or cancellation where:

- The restarting thread calls _lwp_exit() before another thread gets around
  to waking it with _lwp_unpark(), leading to ESRCH (observed by joerg@).
  (I may have removed a similar check mistakenly over the weekend.)

- The restarting thread considers itself gone off the sleep queue but
  at the same time another thread is part way through waking it, and hasn't
  fully completed that operation yet by setting thread->pt_mutexwait = 0.
  I think that could have potentially lead to the list of waiters getting
  messed up given the right circumstances.


To generate a diff of this commit:
cvs rdiff -u -r1.172 -r1.173 src/lib/libpthread/pthread.c
cvs rdiff -u -r1.70 -r1.71 src/lib/libpthread/pthread_cond.c
cvs rdiff -u -r1.78 -r1.79 src/lib/libpthread/pthread_mutex.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.