Fix pthread_join() to actually wait for children. Fix semaphores and also

provide a simple producer/consumer test program.
This commit is contained in:
gbeauche 2004-01-04 16:27:50 +00:00
parent 9723f1d495
commit 5ce5736c89

View File

@ -57,6 +57,11 @@ extern int __clone(int (*fn)(void *), void *, int, void *);
#define sem_value __sem_value
#define sem_waiting __sem_waiting
/* Wait for "clone" children only (Linux 2.4+ specific) */
#ifndef __WCLONE
#define __WCLONE 0
#endif
/*
* Return pthread ID of self
@ -137,7 +142,7 @@ int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void *(*start_
int pthread_join(pthread_t thread, void **ret)
{
do {
if (waitpid(thread, NULL, 0) >= 0)
if (waitpid(thread, NULL, __WCLONE) >= 0);
break;
} while (errno == EINTR);
if (ret)
@ -325,7 +330,9 @@ void null_handler(int sig)
int sem_wait(sem_t *sem)
{
acquire_spinlock(&sem->sem_lock.spinlock);
if (atomic_add((int *)&sem->sem_value, -1) >= 0) {
if (sem->sem_value > 0)
atomic_add((int *)&sem->sem_value, -1);
else {
sigset_t mask;
if (!sem->sem_lock.status) {
struct sigaction sa;
@ -352,9 +359,67 @@ int sem_wait(sem_t *sem)
int sem_post(sem_t *sem)
{
acquire_spinlock(&sem->sem_lock.spinlock);
atomic_add((int *)&sem->sem_value, 1);
if (sem->sem_waiting)
if (sem->sem_waiting == NULL)
atomic_add((int *)&sem->sem_value, 1);
else
kill((pid_t)sem->sem_waiting, sem->sem_lock.status);
release_spinlock(&sem->sem_lock.spinlock);
return 0;
}
/*
* Simple producer/consumer test program
*/
#ifdef TEST
#include <stdio.h>
static sem_t p_sem, c_sem;
static int data = 0;
static void *producer_func(void *arg)
{
int i, n = (int)arg;
for (i = 0; i < n; i++) {
sem_wait(&p_sem);
data++;
sem_post(&c_sem);
}
return NULL;
}
static void *consumer_func(void *arg)
{
int i, n = (int)arg;
for (i = 0; i < n; i++) {
sem_wait(&c_sem);
printf("data: %d\n", data);
sem_post(&p_sem);
}
sleep(1); // for testing pthread_join()
return NULL;
}
int main(void)
{
pthread_t producer_thread, consumer_thread;
static const int N = 5;
if (sem_init(&c_sem, 0, 0) < 0)
return 1;
if (sem_init(&p_sem, 0, 1) < 0)
return 2;
if (pthread_create(&producer_thread, NULL, producer_func, (void *)N) != 0)
return 3;
if (pthread_create(&consumer_thread, NULL, consumer_func, (void *)N) != 0)
return 4;
pthread_join(producer_thread, NULL);
pthread_join(consumer_thread, NULL);
sem_destroy(&p_sem);
sem_destroy(&c_sem);
if (data != N)
return 5;
return 0;
}
#endif