diff options
Diffstat (limited to 'src/thread/sem_post.c')
| -rw-r--r-- | src/thread/sem_post.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/src/thread/sem_post.c b/src/thread/sem_post.c index 31e3293d..5c2517f2 100644 --- a/src/thread/sem_post.c +++ b/src/thread/sem_post.c @@ -1,17 +1,21 @@ #include <semaphore.h> +#include <limits.h> #include "pthread_impl.h" int sem_post(sem_t *sem) { - int val, waiters, priv = sem->__val[2]; + 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, priv); + 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; } |