sig_cond_reltimedwait
extern int sig_cond_reltimedwait(cond_t *, mutex_t *, const timespec_t *);
extern int sig_cond_reltimedwait(cond_t *, mutex_t *, const timespec_t *);
uerrno = sig_cond_reltimedwait(&_aio_iowait_cv,
cv_err = sig_cond_reltimedwait(&_aio_iowait_cv,
if (sig_cond_reltimedwait(&tpool->tp_workcv,