Function sleepq_timedwait

freebsd/kern/subr_sleepqueue.c:681–693

* Block the current thread until it is awakened from its sleep queue * or it times out while waiting. */

 * or it times out while waiting.
 */
int
sleepq_timedwait(const void *wchan, int pri)
{
	struct thread *td;

	td = curthread;
	MPASS(!(td->td_flags & TDF_SINTR));

	thread_lock(td);
	sleepq_switch(wchan, pri);

	return (sleepq_check_timeout());
}

/*
 * Block the current thread until it is awakened from its sleep queue,