Redesigned how cancellation unblocks a thread from internal cancellation points (sem_wait, pthread_join, pthread_cond_{wait,timedwait}). Cancellation won't eat a signal in any of these functions (*required* by POSIX and Single Unix Spec!).

2000-01-03  Kaz Kylheku  <kaz@ashi.footprints.net>

	Redesigned how cancellation unblocks a thread from internal
	cancellation points (sem_wait, pthread_join,
	pthread_cond_{wait,timedwait}).
	Cancellation won't eat a signal in any of these functions
	(*required* by POSIX and Single Unix Spec!).
	* condvar.c: spontaneous wakeup on pthread_cond_timedwait won't eat a
	simultaneous condition variable signal (not required by POSIX
	or Single Unix Spec, but nice).
	* spinlock.c: __pthread_lock queues back any received restarts
	that don't belong to it instead of assuming ownership of lock
	upon any restart; fastlock can no longer be acquired by two threads
	simultaneously.
	* restart.h: restarts queue even on kernels that don't have
	queued real time signals (2.0, early 2.1), thanks to atomic counter,
	avoiding a rare race condition in pthread_cond_timedwait.

1 files changed, 3 insertions, 2 deletions

diff --git a/linuxthreads/queue.h b/linuxthreads/queue.h
index fa8c5d861d..f87322f84a 100644
--- a/linuxthreads/queue.h
+++ b/linuxthreads/queue.h
@@ -43,13 +43,14 @@ static inline pthread_descr dequeue(pthread_descr * q)
   return th;
 }
 
-static inline void remove_from_queue(pthread_descr * q, pthread_descr th)
+static inline int remove_from_queue(pthread_descr * q, pthread_descr th)
 {
   for (; *q != NULL; q = &((*q)->p_nextwaiting)) {
     if (*q == th) {
       *q = th->p_nextwaiting;
       th->p_nextwaiting = NULL;
-      return;
+      return 1;
     }
   }
+  return 0;
 }