Function dev_refthread

freebsd/kern/kern_conf.c:178–202

}

struct cdevsw *
dev_refthread(struct cdev *dev, int *ref)
{
	struct cdevsw *csw;
	struct cdev_priv *cdp;

	dev_lock_assert_unlocked();
	if ((dev->si_flags & SI_ETERNAL) != 0) {
		*ref = 0;
		return (dev->si_devsw);
	}
	cdp = cdev2priv(dev);
	mtx_lock(&cdp->cdp_threadlock);
	csw = dev->si_devsw;
	if (csw != NULL) {
		if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
			atomic_add_long(&dev->si_threadcount, 1);
		else
			csw = NULL;
	}
	mtx_unlock(&cdp->cdp_threadlock);
	if (csw != NULL)
		*ref = 1;
	return (csw);
}

struct cdevsw *
devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref)