net: nsos_sockets: notify pollers on socket close

Raise the poll signal when the socket is being closed to prevent users
of `zsock_poll` blocking after the socket is no more.

Signed-off-by: Jordan Yates <[email protected]>

Author: JordanYates

drivers/net/nsos_sockets.c

@@ -258,13 +258,21 @@ static ssize_t nsos_write(void *obj, const void *buf, size_t sz)
 static int nsos_close(void *obj)
 {
 	struct nsos_socket *sock = obj;
+	struct nsos_socket_poll *poll;
 	int ret;
 
 	ret = nsi_host_close(sock->poll.mid.fd);
 	if (ret < 0) {
 		errno = nsos_adapt_get_zephyr_errno();
 	}
 
+	SYS_DLIST_FOR_EACH_CONTAINER(&nsos_polls, poll, node) {
+		if (poll == &sock->poll) {
+			poll->mid.revents = ZSOCK_POLLHUP;
+			poll->mid.cb(&poll->mid);
+		}
+	}
+
 	k_free(sock);
 
 	return ret;