return
	}

	// Use port_alert to put portfd into alert mode.
	// This will wake up all threads sleeping in port_getn on portfd,
	// and cause their calls to port_getn to return immediately.
	// Further, until portfd is taken out of alert mode,
	// all calls to port_getn will return immediately.
	if port_alert(portfd, _PORT_ALERT_UPDATE, _POLLHUP, uintptr(unsafe.Pointer(&portfd))) < 0 {

	portGen := newPortGenerators()
	for _, p := range c.Ports {
		if p.ServicePort > 0 {
			if portGen.Service.IsUsed(p.ServicePort) {
				return fmt.Errorf("failed configuring port %s: service port already used %d", p.Name, p.ServicePort)
			}
			portGen.Service.SetUsed(p.ServicePort)
		}
		if p.WorkloadPort > 0 {
			if portGen.Instance.IsUsed(p.WorkloadPort) {

	if (ret) {
		fprintf(stderr, "runtime/cgo: mach_port_allocate failed for port_set: %d\n", ret);
		abort();
	}

	// Block all signals to the exception handler thread
	sigfillset(&ign);
	pthread_sigmask(SIG_SETMASK, &ign, &oset);

	// Start a thread to handle exceptions.
	uintptr_t port_set = (uintptr_t)mach_exception_handler_port_set;
	pthread_attr_init(&attr);