diff options
Diffstat (limited to 'lib/librthread')
| -rw-r--r-- | lib/librthread/rthread_sem.c | 54 |
1 files changed, 25 insertions, 29 deletions
diff --git a/lib/librthread/rthread_sem.c b/lib/librthread/rthread_sem.c index 7de0e832363..4645eaddf9d 100644 --- a/lib/librthread/rthread_sem.c +++ b/lib/librthread/rthread_sem.c @@ -1,4 +1,4 @@ -/* $OpenBSD: rthread_sem.c,v 1.29 2018/06/08 13:53:01 pirofti Exp $ */ +/* $OpenBSD: rthread_sem.c,v 1.30 2019/01/29 17:43:23 mpi Exp $ */ /* * Copyright (c) 2004,2005,2013 Ted Unangst <tedu@openbsd.org> * Copyright (c) 2018 Paul Irofti <pirofti@openbsd.org> @@ -39,8 +39,6 @@ #include "cancel.h" /* in libc/include */ #include "synch.h" -#define SHARED_IDENT ((void *)-1) - /* SHA256_DIGEST_STRING_LENGTH includes nul */ /* "/tmp/" + sha256 + ".sem" */ #define SEM_PATH_SIZE (5 + SHA256_DIGEST_STRING_LENGTH + 4) @@ -61,31 +59,30 @@ int _sem_wait(sem_t sem, int can_eintr, const struct timespec *abstime, int *delayed_cancel) { - int r = 0; - int v, ov; + unsigned int val; + int error = 0; atomic_inc_int(&sem->waitcount); for (;;) { - while ((v = sem->value) > 0) { - ov = atomic_cas_uint(&sem->value, v, v - 1); - if (ov == v) { + while ((val = sem->value) > 0) { + if (atomic_cas_uint(&sem->value, val, val - 1) == val) { membar_enter_after_atomic(); atomic_dec_int(&sem->waitcount); - return 0; + return (0); } } - if (r) + if (error) break; - r = _twait(&sem->value, 0, CLOCK_REALTIME, abstime); + error = _twait(&sem->value, 0, CLOCK_REALTIME, abstime); /* ignore interruptions other than cancelation */ - if ((r == ECANCELED && *delayed_cancel == 0) || - (r == EINTR && !can_eintr) || r == EAGAIN) - r = 0; + if ((error == ECANCELED && *delayed_cancel == 0) || + (error == EINTR && !can_eintr) || error == EAGAIN) + error = 0; } atomic_dec_int(&sem->waitcount); - return r; + return (error); } /* always increment count */ @@ -223,7 +220,7 @@ sem_wait(sem_t *semp) struct tib *tib = TIB_GET(); pthread_t self; sem_t sem; - int r; + int error; PREP_CANCEL_POINT(tib); if (!_threads_ready) @@ -236,11 +233,11 @@ sem_wait(sem_t *semp) } ENTER_DELAYED_CANCEL_POINT(tib, self); - r = _sem_wait(sem, 1, NULL, &self->delayed_cancel); - LEAVE_CANCEL_POINT_INNER(tib, r); + error = _sem_wait(sem, 1, NULL, &self->delayed_cancel); + LEAVE_CANCEL_POINT_INNER(tib, error); - if (r) { - errno = r; + if (error) { + errno = error; _rthread_debug(1, "%s: v=%d errno=%d\n", __func__, sem->value, errno); return (-1); @@ -255,7 +252,7 @@ sem_timedwait(sem_t *semp, const struct timespec *abstime) struct tib *tib = TIB_GET(); pthread_t self; sem_t sem; - int r; + int error; PREP_CANCEL_POINT(tib); if (!semp || !(sem = *semp) || abstime == NULL || @@ -269,11 +266,11 @@ sem_timedwait(sem_t *semp, const struct timespec *abstime) self = tib->tib_thread; ENTER_DELAYED_CANCEL_POINT(tib, self); - r = _sem_wait(sem, 1, abstime, &self->delayed_cancel); - LEAVE_CANCEL_POINT_INNER(tib, r); + error = _sem_wait(sem, 1, abstime, &self->delayed_cancel); + LEAVE_CANCEL_POINT_INNER(tib, error); - if (r) { - errno = r == EWOULDBLOCK ? ETIMEDOUT : r; + if (error) { + errno = (error == EWOULDBLOCK) ? ETIMEDOUT : error; _rthread_debug(1, "%s: v=%d errno=%d\n", __func__, sem->value, errno); return (-1); @@ -286,16 +283,15 @@ int sem_trywait(sem_t *semp) { sem_t sem; - int v, ov; + unsigned int val; if (!semp || !(sem = *semp)) { errno = EINVAL; return (-1); } - while ((v = sem->value) > 0) { - ov = atomic_cas_uint(&sem->value, v, v - 1); - if (ov == v) { + while ((val = sem->value) > 0) { + if (atomic_cas_uint(&sem->value, val, val - 1) == val) { membar_enter_after_atomic(); return (0); } |