Update.

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.