Update.
2001-05-01 Kaz Kylheku <kaz@ashi.footprints.net>
Memory barrier overhaul following line by line inspection.
* mutex.c (pthread_once): Missing memory barriers added.
* pthread.c (__pthread_wait_for_restart_signal,
__pthread_timedsuspend_new, __pthread_restart_new): Added
memory barriers ``just in case'' and for documentary value.
* spinlock.c (__pthread_release): New inline function for releasing
spinlock, to complement __pthread_acquire. Includes memory
barrier prior to assignment to spinlock, and __asm __volatile
dance to prevent reordering or optimization of the spinlock access.
* spinlock.c (__pthread_unlock, __pthread_alt_lock,
__pthread_alt_timedlock, __pthread_alt_unlock,
__pthread_compare_and_swap): Updated to use new __pthread_release
instead of updating spinlock directly.
* spinlock.c (__pthread_lock, __pthread_unlock, wait_node_alloc,
wait_node_free, wait_node_dequeue, __pthread_alt_lock,
__pthread_alt_timedlock, __pthread_alt_unlock, __pthread_acquire):
Memory barrier overhaul. Lots of missing memory barriers added,
a couple needless ones removed.
* spinlock.c (__pthread_compare_and_swap): testandset optimization
removed, just calls __pthread_acquire, which has the new read
barrier in it before its testandset.