diff options
author | Miod Vallat <miod@cvs.openbsd.org> | 2002-11-01 20:15:04 +0000 |
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committer | Miod Vallat <miod@cvs.openbsd.org> | 2002-11-01 20:15:04 +0000 |
commit | 82e958ef880266c36148d5aaeb42d95ef380087f (patch) | |
tree | b457e68407c2be0011c2a0f9f138607023d2deeb /lib/libpthread | |
parent | 9c3dd382bf4e91cc099142395a8e07501f5bfbdf (diff) |
Working atomic locks on vax for libc_r.
ok marc@
Diffstat (limited to 'lib/libpthread')
-rw-r--r-- | lib/libpthread/arch/vax/_atomic_lock.c | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/lib/libpthread/arch/vax/_atomic_lock.c b/lib/libpthread/arch/vax/_atomic_lock.c index aedbb86c1dd..b85f55e744f 100644 --- a/lib/libpthread/arch/vax/_atomic_lock.c +++ b/lib/libpthread/arch/vax/_atomic_lock.c @@ -1,4 +1,4 @@ -/* $OpenBSD: _atomic_lock.c,v 1.2 2002/10/11 19:08:41 marc Exp $ */ +/* $OpenBSD: _atomic_lock.c,v 1.3 2002/11/01 20:14:59 miod Exp $ */ /* * Atomic lock for vax @@ -9,5 +9,33 @@ int _atomic_lock(volatile _spinlock_lock_t *lock) { - return (_thread_slow_atomic_lock(lock)); + _spinlock_lock_t old; + + /* + * The Branch on Bit Set and Set Interlocked instruction + * sets a given bit in a register or a memory location, as an + * atomic, interlocked operation. + * If the bit was set, execution continues at the branch + * location. + * + * For more details, please refer to the Vax Architecture + * Reference Manual, chapter 3 (Instructions), section + * ``Control instructions''. + */ + __asm__ ( + "movl $1, %1\n" /* _SPINLOCK_LOCKED */ + "bbssi $0, %0, 1f\n" + "movl $0, %1\n" /* _SPINLOCK_UNLOCKED */ + "1: \n" + : "=m" (*lock), "=r" (old) : "0" (*lock) + ); + + return (old != _SPINLOCK_UNLOCKED); +} + +int +_atomic_is_locked(volatile _spinlock_lock_t *lock) +{ + + return (*lock != _SPINLOCK_UNLOCKED); } |