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authorGuido van Rossum <guido@python.org>1997-01-17 21:06:41 (GMT)
committerGuido van Rossum <guido@python.org>1997-01-17 21:06:41 (GMT)
commit7af8130857b81ef5e15901cd71212d7d4cda65db (patch)
tree5f425dfb48f293010b809518c8b3e3ab63213998
parentdd5db439058df23ceca517620cda9e6420aff4cf (diff)
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Working semaphore implementation by Sjoerd.
-rw-r--r--Python/thread_pthread.h67
1 files changed, 64 insertions, 3 deletions
diff --git a/Python/thread_pthread.h b/Python/thread_pthread.h
index 65bae3e..c83cd2d 100644
--- a/Python/thread_pthread.h
+++ b/Python/thread_pthread.h
@@ -263,32 +263,93 @@ void release_lock _P1(lock, type_lock lock)
/*
* Semaphore support.
*/
-/* NOTE: 100% non-functional at this time - tim */
+
+struct semaphore {
+ pthread_mutex_t mutex;
+ pthread_cond_t cond;
+ int value;
+};
type_sema allocate_sema _P1(value, int value)
{
- char *sema = 0;
+ struct semaphore *sema;
+ int status, error = 0;
+
dprintf(("allocate_sema called\n"));
if (!initialized)
init_thread();
+ sema = (struct semaphore *) malloc(sizeof(struct semaphore));
+ if (sema != NULL) {
+ sema->value = value;
+ status = pthread_mutex_init(&sema->mutex,
+ pthread_mutexattr_default);
+ CHECK_STATUS("pthread_mutex_init");
+ status = pthread_cond_init(&sema->cond,
+ pthread_condattr_default);
+ CHECK_STATUS("pthread_cond_init");
+ if (error) {
+ free((void *) sema);
+ sema = NULL;
+ }
+ }
dprintf(("allocate_sema() -> %lx\n", (long) sema));
return (type_sema) sema;
}
void free_sema _P1(sema, type_sema sema)
{
+ int status, error = 0;
+ struct semaphore *thesema = (struct semaphore *) sema;
+
dprintf(("free_sema(%lx) called\n", (long) sema));
+ status = pthread_cond_destroy(&thesema->cond);
+ CHECK_STATUS("pthread_cond_destroy");
+ status = pthread_mutex_destroy(&thesema->mutex);
+ CHECK_STATUS("pthread_mutex_destroy");
+ free((void *) thesema);
}
int down_sema _P2(sema, type_sema sema, waitflag, int waitflag)
{
+ int status, error = 0, success;
+ struct semaphore *thesema = (struct semaphore *) sema;
+
dprintf(("down_sema(%lx, %d) called\n", (long) sema, waitflag));
+ status = pthread_mutex_lock(&thesema->mutex);
+ CHECK_STATUS("pthread_mutex_lock");
+ if (waitflag) {
+ while (!error && thesema->value <= 0) {
+ status = pthread_cond_wait(&thesema->cond,
+ &thesema->mutex);
+ CHECK_STATUS("pthread_cond_wait");
+ }
+ }
+ if (error)
+ success = 0;
+ else if (thesema->value > 0) {
+ thesema->value--;
+ success = 1;
+ }
+ else
+ success = 0;
+ status = pthread_mutex_unlock(&thesema->mutex);
+ CHECK_STATUS("pthread_mutex_unlock");
dprintf(("down_sema(%lx) return\n", (long) sema));
- return -1;
+ return success;
}
void up_sema _P1(sema, type_sema sema)
{
+ int status, error = 0;
+ struct semaphore *thesema = (struct semaphore *) sema;
+
dprintf(("up_sema(%lx)\n", (long) sema));
+ status = pthread_mutex_lock(&thesema->mutex);
+ CHECK_STATUS("pthread_mutex_lock");
+ thesema->value++;
+ status = pthread_cond_signal(&thesema->cond);
+ CHECK_STATUS("pthread_cond_signal");
+ status = pthread_mutex_unlock(&thesema->mutex);
+ CHECK_STATUS("pthread_mutex_unlock");
}