Function sorflush

freebsd/kern/uipc_socket.c:2868–2914

}

void
sorflush(struct socket *so)
{
	struct sockbuf *sb = &so->so_rcv;
	struct protosw *pr = so->so_proto;
	struct socket aso;

	VNET_SO_ASSERT(so);

	/*
	 * In order to avoid calling dom_dispose with the socket buffer mutex
	 * held, and in order to generally avoid holding the lock for a long
	 * time, we make a copy of the socket buffer and clear the original
	 * (except locks, state).  The new socket buffer copy won't have
	 * initialized locks so we can only call routines that won't use or
	 * assert those locks.
	 *
	 * Dislodge threads currently blocked in receive and wait to acquire
	 * a lock against other simultaneous readers before clearing the
	 * socket buffer.  Don't let our acquire be interrupted by a signal
	 * despite any existing socket disposition on interruptable waiting.
	 */
	socantrcvmore(so);
	(void) sblock(sb, SBL_WAIT | SBL_NOINTR);

	/*
	 * Invalidate/clear most of the sockbuf structure, but leave selinfo
	 * and mutex data unchanged.
	 */
	SOCKBUF_LOCK(sb);
	bzero(&aso, sizeof(aso));
	aso.so_pcb = so->so_pcb;
	bcopy(&sb->sb_startzero, &aso.so_rcv.sb_startzero,
	    sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
	bzero(&sb->sb_startzero,
	    sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
	SOCKBUF_UNLOCK(sb);
	sbunlock(sb);

	/*
	 * Dispose of special rights and flush the copied socket.  Don't call
	 * any unsafe routines (that rely on locks being initialized) on aso.
	 */
	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
		(*pr->pr_domain->dom_dispose)(&aso);
	sbrelease_internal(&aso.so_rcv, so);
}

/*
 * Wrapper for Socket established helper hook.