#include <semaphore.h>
+#include <limits.h>
#include "pthread_impl.h"
int sem_post(sem_t *sem)
{
- int val, waiters;
+ int val, new, waiters, priv = sem->__val[2];
do {
val = sem->__val[0];
waiters = sem->__val[1];
- if (val == SEM_VALUE_MAX) {
+ if ((val & SEM_VALUE_MAX) == SEM_VALUE_MAX) {
errno = EOVERFLOW;
return -1;
}
- } while (a_cas(sem->__val, val, val+1+(val<0)) != val);
- if (val<0 || waiters) __wake(sem->__val, 1, 0);
+ new = val + 1;
+ if (waiters <= 1)
+ new &= ~0x80000000;
+ } while (a_cas(sem->__val, val, new) != val);
+ if (val<0) __wake(sem->__val, waiters>1 ? 1 : -1, priv);
return 0;
}