report sem value overflows in sem_post

this is not required by the standard, but it's nicer than corrupting
the state and rather inexpensive.
This commit is contained in:
Rich Felker 2011-10-26 00:28:47 -04:00
parent 42976cee2d
commit 26120950e2
1 changed files with 4 additions and 0 deletions

View File

@ -7,6 +7,10 @@ int sem_post(sem_t *sem)
do {
val = sem->__val[0];
waiters = sem->__val[1];
if (val == 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);
return 0;