int mutex_trylock(smx_mutex_t mutex);
void mutex_unlock(smx_mutex_t mutex);
-smx_cond_t cond_init() [[nohandler]];
void cond_wait(smx_cond_t cond, smx_mutex_t mutex) [[block]];
-void cond_wait_timeout(smx_cond_t cond, smx_mutex_t mutex, double timeout) [[block]];
+int cond_wait_timeout(smx_cond_t cond, smx_mutex_t mutex, double timeout) [[block]];
void sem_acquire(smx_sem_t sem) [[block]];
-void sem_acquire_timeout(smx_sem_t sem, double timeout) [[block]];
+int sem_acquire_timeout(smx_sem_t sem, double timeout) [[block]];
sg_size_t storage_read(surf_storage_t st, sg_size_t size) [[block]];
sg_size_t storage_write(surf_storage_t st, sg_size_t size) [[block]];