[_mutex unlock];
	}
#endif
}

- (void)observeForTimeInterval: (of_time_interval_t)timeInterval
{
	void *pool = objc_autoreleasePoolPush();
	struct timespec timeout;
	struct kevent eventList[EVENTLIST_SIZE];
	int events;

	if ([self OF_processReadBuffers])
		return;

	timeout.tv_sec = (time_t)timeInterval;
	timeout.tv_nsec = lrint((timeInterval - timeout.tv_sec) * 1000000000);

	[self OF_processReadBuffers];

	objc_autoreleasePoolPop(pool);

	events = kevent(_kernelQueue, NULL, 0, eventList, EVENTLIST_SIZE,
	    (timeInterval != -1 ? &timeout : NULL));

	if (events < 0)
		@throw [OFObserveFailedException exceptionWithObserver: self
								 errNo: errno];

	for (int i = 0; i < events; i++) {
		void *pool;

		if (eventList[i].flags & EV_ERROR)
			@throw [OFObserveFailedException
			    exceptionWithObserver: self
					    errNo: (int)eventList[i].data];

		if (eventList[i].ident == _cancelFD[0]) {
			char buffer;