#include <sys/stat.h>
#include <stdlib.h>
#include <pthread.h>
-#include "libc.h"
+#include "lock.h"
+#include "fork_impl.h"
-char *__shm_mapname(const char *, char *);
+#define malloc __libc_malloc
+#define calloc __libc_calloc
+#define realloc undef
+#define free undef
static struct {
ino_t ino;
sem_t *sem;
int refcnt;
} *semtab;
-static int lock[2];
+static volatile int lock[1];
+volatile int *const __sem_open_lockptr = lock;
#define FLAGS (O_RDWR|O_NOFOLLOW|O_CLOEXEC|O_NONBLOCK)
flags &= (O_CREAT|O_EXCL);
+ pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+
/* Early failure check for exclusive open; otherwise the case
* where the semaphore already exists is expensive. */
if (flags == (O_CREAT|O_EXCL) && access(name, F_OK) == 0) {
errno = EEXIST;
- return SEM_FAILED;
+ goto fail;
}
- pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
-
for (;;) {
/* If exclusive mode is not requested, try opening an
* existing file first and fall back to creation. */
goto fail;
}
close(fd);
- if (link(tmp, name) == 0) break;
- e = errno;
+ e = link(tmp, name) ? errno : 0;
unlink(tmp);
+ if (!e) break;
+ munmap(map, sizeof(sem_t));
/* Failure is only fatal when doing an exclusive open;
* otherwise, next iteration will try to open the
* existing file. */
fail:
pthread_setcancelstate(cs, 0);
+ LOCK(lock);
+ semtab[slot].sem = 0;
+ UNLOCK(lock);
return SEM_FAILED;
}
int i;
LOCK(lock);
for (i=0; i<SEM_NSEMS_MAX && semtab[i].sem != sem; i++);
- if (!--semtab[i].refcnt) {
- semtab[i].sem = 0;
- semtab[i].ino = 0;
+ if (--semtab[i].refcnt) {
+ UNLOCK(lock);
+ return 0;
}
+ semtab[i].sem = 0;
+ semtab[i].ino = 0;
UNLOCK(lock);
munmap(sem, sizeof *sem);
return 0;