diff options
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/kern/kern_rwlock.c | 39 | ||||
| -rw-r--r-- | sys/sys/rwlock.h | 6 |
2 files changed, 31 insertions, 14 deletions
diff --git a/sys/kern/kern_rwlock.c b/sys/kern/kern_rwlock.c index 85f1e6ace92..3641403f369 100644 --- a/sys/kern/kern_rwlock.c +++ b/sys/kern/kern_rwlock.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kern_rwlock.c,v 1.10 2007/04/04 18:01:57 art Exp $ */ +/* $OpenBSD: kern_rwlock.c,v 1.11 2007/05/04 12:56:15 art Exp $ */ /* * Copyright (c) 2002, 2003 Artur Grabowski <art@openbsd.org> @@ -31,6 +31,8 @@ #include <sys/rwlock.h> #include <sys/limits.h> +#include <machine/lock.h> + /* XXX - temporary measure until proc0 is properly aligned */ #define RW_PROC(p) (((long)p) & ~RWLOCK_MASK) @@ -86,7 +88,7 @@ rw_enter_read(struct rwlock *rwl) unsigned long owner = rwl->rwl_owner; if (__predict_false((owner & RWLOCK_WRLOCK) || - rw_test_and_set(&rwl->rwl_owner, owner, owner + RWLOCK_READ_INCR))) + rw_cas(&rwl->rwl_owner, owner, owner + RWLOCK_READ_INCR))) rw_enter(rwl, RW_READ); } @@ -95,7 +97,7 @@ rw_enter_write(struct rwlock *rwl) { struct proc *p = curproc; - if (__predict_false(rw_test_and_set(&rwl->rwl_owner, 0, + if (__predict_false(rw_cas(&rwl->rwl_owner, 0, RW_PROC(p) | RWLOCK_WRLOCK))) rw_enter(rwl, RW_WRITE); } @@ -106,7 +108,7 @@ rw_exit_read(struct rwlock *rwl) unsigned long owner = rwl->rwl_owner; if (__predict_false((owner & RWLOCK_WAIT) || - rw_test_and_set(&rwl->rwl_owner, owner, owner - RWLOCK_READ_INCR))) + rw_cas(&rwl->rwl_owner, owner, owner - RWLOCK_READ_INCR))) rw_exit(rwl); } @@ -116,12 +118,13 @@ rw_exit_write(struct rwlock *rwl) unsigned long owner = rwl->rwl_owner; if (__predict_false((owner & RWLOCK_WAIT) || - rw_test_and_set(&rwl->rwl_owner, owner, 0))) + rw_cas(&rwl->rwl_owner, owner, 0))) rw_exit(rwl); } +#ifndef rw_cas int -rw_test_and_set(volatile unsigned long *p, unsigned long o, unsigned long n) +rw_cas(volatile unsigned long *p, unsigned long o, unsigned long n) { if (*p != o) return (1); @@ -131,6 +134,8 @@ rw_test_and_set(volatile unsigned long *p, unsigned long o, unsigned long n) } #endif +#endif + #ifdef DIAGNOSTIC /* * Put the diagnostic functions here to keep the main code free @@ -175,16 +180,17 @@ int rw_enter(struct rwlock *rwl, int flags) { const struct rwlock_op *op; + struct sleep_state sls; unsigned long inc, o; - int error, prio; + int error; op = &rw_ops[flags & RW_OPMASK]; inc = op->inc + RW_PROC(curproc) * op->proc_mult; retry: while (__predict_false(((o = rwl->rwl_owner) & op->check) != 0)) { - if (rw_test_and_set(&rwl->rwl_owner, o, o | op->wait_set)) - continue; + unsigned long set = o | op->wait_set; + int do_sleep, prio; prio = op->wait_prio; if (flags & RW_INTR) @@ -194,13 +200,22 @@ retry: if (flags & RW_NOSLEEP) return (EBUSY); - if ((error = tsleep(rwl, prio, rwl->rwl_name, 0)) != 0) + + sleep_setup(&sls, rwl, op->wait_prio, rwl->rwl_name); + if (flags & RW_INTR) + sleep_setup_signal(&sls, op->wait_prio | PCATCH); + + do_sleep = !rw_cas(&rwl->rwl_owner, o, set); + + sleep_finish(&sls, do_sleep); + if ((flags & RW_INTR) && + (error = sleep_finish_signal(&sls)) != 0) return (error); if (flags & RW_SLEEPFAIL) return (EAGAIN); } - if (__predict_false(rw_test_and_set(&rwl->rwl_owner, o, o + inc))) + if (__predict_false(rw_cas(&rwl->rwl_owner, o, o + inc))) goto retry; /* @@ -229,7 +244,7 @@ rw_exit(struct rwlock *rwl) else set = (owner - RWLOCK_READ_INCR) & ~(RWLOCK_WAIT|RWLOCK_WRWANT); - } while (rw_test_and_set(&rwl->rwl_owner, owner, set)); + } while (rw_cas(&rwl->rwl_owner, owner, set)); if (owner & RWLOCK_WAIT) wakeup(rwl); diff --git a/sys/sys/rwlock.h b/sys/sys/rwlock.h index 405b9d9351d..61c48eea1ce 100644 --- a/sys/sys/rwlock.h +++ b/sys/sys/rwlock.h @@ -1,4 +1,4 @@ -/* $OpenBSD: rwlock.h,v 1.9 2007/04/04 18:01:57 art Exp $ */ +/* $OpenBSD: rwlock.h,v 1.10 2007/05/04 12:56:15 art Exp $ */ /* * Copyright (c) 2002 Artur Grabowski <art@openbsd.org> * All rights reserved. @@ -106,6 +106,8 @@ void rw_exit(struct rwlock *); #define RW_SLEEPFAIL 0x20UL /* fail if we slept for the lock */ #define RW_NOSLEEP 0x40UL /* don't wait for the lock */ -int rw_test_and_set(volatile unsigned long *, unsigned long, unsigned long); +#ifndef rw_cas +int rw_cas(volatile unsigned long *, unsigned long, unsigned long); +#endif #endif |