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Diffstat (limited to 'lib/libc_r/uthread/uthread_cond.c')
-rw-r--r--lib/libc_r/uthread/uthread_cond.c85
1 files changed, 62 insertions, 23 deletions
diff --git a/lib/libc_r/uthread/uthread_cond.c b/lib/libc_r/uthread/uthread_cond.c
index aef5daac188..aed1adc7662 100644
--- a/lib/libc_r/uthread/uthread_cond.c
+++ b/lib/libc_r/uthread/uthread_cond.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: uthread_cond.c,v 1.7 1999/06/09 07:06:54 d Exp $ */
+/* $OpenBSD: uthread_cond.c,v 1.8 1999/11/25 07:01:33 d Exp $ */
/*
* Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
* All rights reserved.
@@ -30,6 +30,7 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
+ * $FreeBSD: uthread_cond.c,v 1.18 1999/08/30 00:02:07 deischen Exp $
*/
#include <stdlib.h>
#include <errno.h>
@@ -45,6 +46,28 @@ static inline pthread_t cond_queue_deq(pthread_cond_t);
static inline void cond_queue_remove(pthread_cond_t, pthread_t);
static inline void cond_queue_enq(pthread_cond_t, pthread_t);
+/* Reinitialize a condition variable to defaults. */
+int
+_cond_reinit(pthread_cond_t * cond)
+{
+ int ret = 0;
+
+ if (cond == NULL)
+ ret = EINVAL;
+ else if (*cond == NULL)
+ ret = pthread_cond_init(cond, NULL);
+ else {
+ /*
+ * Initialize the condition variable structure:
+ */
+ TAILQ_INIT(&(*cond)->c_queue);
+ (*cond)->c_flags = COND_FLAGS_INITED;
+ (*cond)->c_type = COND_TYPE_FAST;
+ (*cond)->c_mutex = NULL;
+ memset(&(*cond)->lock, 0, sizeof((*cond)->lock));
+ }
+ return (ret);
+}
int
pthread_cond_init(pthread_cond_t * cond, const pthread_condattr_t * cond_attr)
@@ -96,7 +119,7 @@ pthread_cond_init(pthread_cond_t * cond, const pthread_condattr_t * cond_attr)
pcond->c_flags |= COND_FLAGS_INITED;
pcond->c_type = type;
pcond->c_mutex = NULL;
- _SPINUNLOCK(&pcond->lock);
+ _SPINLOCK_INIT(&pcond->lock);
*cond = pcond;
}
}
@@ -136,6 +159,7 @@ int
pthread_cond_wait(pthread_cond_t * cond, pthread_mutex_t * mutex)
{
int rval = 0;
+ int status;
/* This is a cancellation point: */
_thread_enter_cancellation_point();
@@ -149,6 +173,9 @@ pthread_cond_wait(pthread_cond_t * cond, pthread_mutex_t * mutex)
*/
else if (*cond != NULL ||
(rval = pthread_cond_init(cond,NULL)) == 0) {
+ /* Lock the condition variable structure: */
+ _SPINLOCK(&(*cond)->lock);
+
/*
* If the condvar was statically allocated, properly
* initialize the tail queue.
@@ -158,9 +185,6 @@ pthread_cond_wait(pthread_cond_t * cond, pthread_mutex_t * mutex)
(*cond)->c_flags |= COND_FLAGS_INITED;
}
- /* Lock the condition variable structure: */
- _SPINLOCK(&(*cond)->lock);
-
/* Process according to condition variable type: */
switch ((*cond)->c_type) {
/* Fast condition variable: */
@@ -242,11 +266,16 @@ pthread_cond_timedwait(pthread_cond_t * cond, pthread_mutex_t * mutex,
const struct timespec * abstime)
{
int rval = 0;
+ int status;
/* This is a cancellation point: */
_thread_enter_cancellation_point();
- if (cond == NULL)
+ if (cond == NULL || abstime == NULL)
+ rval = EINVAL;
+
+ else if (abstime->tv_sec < 0 ||
+ abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
rval = EINVAL;
/*
@@ -255,6 +284,9 @@ pthread_cond_timedwait(pthread_cond_t * cond, pthread_mutex_t * mutex,
*/
else if (*cond != NULL ||
(rval = pthread_cond_init(cond,NULL)) == 0) {
+ /* Lock the condition variable structure: */
+ _SPINLOCK(&(*cond)->lock);
+
/*
* If the condvar was statically allocated, properly
* initialize the tail queue.
@@ -264,10 +296,6 @@ pthread_cond_timedwait(pthread_cond_t * cond, pthread_mutex_t * mutex,
(*cond)->c_flags |= COND_FLAGS_INITED;
}
-
- /* Lock the condition variable structure: */
- _SPINLOCK(&(*cond)->lock);
-
/* Process according to condition variable type: */
switch ((*cond)->c_type) {
/* Fast condition variable: */
@@ -367,6 +395,7 @@ pthread_cond_timedwait(pthread_cond_t * cond, pthread_mutex_t * mutex,
rval = EINVAL;
break;
}
+
}
/* No longer in a cancellation point: */
@@ -385,6 +414,12 @@ pthread_cond_signal(pthread_cond_t * cond)
if (cond == NULL || *cond == NULL)
rval = EINVAL;
else {
+ /*
+ * Defer signals to protect the scheduling queues
+ * from access by the signal handler:
+ */
+ _thread_kern_sig_defer();
+
/* Lock the condition variable structure: */
_SPINLOCK(&(*cond)->lock);
@@ -419,6 +454,12 @@ pthread_cond_signal(pthread_cond_t * cond)
/* Unlock the condition variable structure: */
_SPINUNLOCK(&(*cond)->lock);
+
+ /*
+ * Undefer and handle pending signals, yielding if
+ * necessary:
+ */
+ _thread_kern_sig_undefer();
}
/* Return the completion status: */
@@ -435,14 +476,10 @@ pthread_cond_broadcast(pthread_cond_t * cond)
rval = EINVAL;
else {
/*
- * Guard against preemption by a scheduling signal.
- * A change of thread state modifies the waiting
- * and priority queues. In addition, we must assure
- * that all threads currently waiting on the condition
- * variable are signaled and are not timedout by a
- * scheduling signal that causes a preemption.
+ * Defer signals to protect the scheduling queues
+ * from access by the signal handler:
*/
- _thread_kern_sched_defer();
+ _thread_kern_sig_defer();
/* Lock the condition variable structure: */
_SPINLOCK(&(*cond)->lock);
@@ -478,9 +515,11 @@ pthread_cond_broadcast(pthread_cond_t * cond)
/* Unlock the condition variable structure: */
_SPINUNLOCK(&(*cond)->lock);
- /* Reenable preemption and yield if necessary.
+ /*
+ * Undefer and handle pending signals, yielding if
+ * necessary:
*/
- _thread_kern_sched_undefer();
+ _thread_kern_sig_undefer();
}
/* Return the completion status: */
@@ -498,7 +537,7 @@ cond_queue_deq(pthread_cond_t cond)
if ((pthread = TAILQ_FIRST(&cond->c_queue)) != NULL) {
TAILQ_REMOVE(&cond->c_queue, pthread, qe);
- pthread->flags &= ~PTHREAD_FLAGS_QUEUED;
+ pthread->flags &= ~PTHREAD_FLAGS_IN_CONDQ;
}
return(pthread);
@@ -517,9 +556,9 @@ cond_queue_remove(pthread_cond_t cond, pthread_t pthread)
* guard against removing the thread from the queue if
* it isn't in the queue.
*/
- if (pthread->flags & PTHREAD_FLAGS_QUEUED) {
+ if (pthread->flags & PTHREAD_FLAGS_IN_CONDQ) {
TAILQ_REMOVE(&cond->c_queue, pthread, qe);
- pthread->flags &= ~PTHREAD_FLAGS_QUEUED;
+ pthread->flags &= ~PTHREAD_FLAGS_IN_CONDQ;
}
}
@@ -545,6 +584,6 @@ cond_queue_enq(pthread_cond_t cond, pthread_t pthread)
tid = TAILQ_NEXT(tid, qe);
TAILQ_INSERT_BEFORE(tid, pthread, qe);
}
- pthread->flags |= PTHREAD_FLAGS_QUEUED;
+ pthread->flags |= PTHREAD_FLAGS_IN_CONDQ;
}
#endif
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-24 17:22:09 +0000