From: Nick Mathewson <nickm@torproject.org>
Date: Mon, 25 Jan 2010 19:07:01 +0000 (-0500)
Subject: Try to untangle the logic in server_port_flush().
X-Git-Tag: release-2.0.4-alpha~58
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=439aea0d072b98daf13ebe3d6eff8ab8ee5bd875;p=libevent

Try to untangle the logic in server_port_flush().

The logic that prevented the first loop in this function from being
infinite was rather confusing and hard to follow.  It seems to confuse
some automatic analysis tools as well as me.  Let's try to replace it
with something more comprehensible.
---

diff --git a/evdns.c b/evdns.c
index 29ea5432..6afe7557 100644
--- a/evdns.c
+++ b/evdns.c
@@ -1418,9 +1418,9 @@ server_port_read(struct evdns_server_port *s) {
 static void
 server_port_flush(struct evdns_server_port *port)
 {
+	struct server_request *req = port->pending_replies;
 	ASSERT_LOCKED(port);
-	while (port->pending_replies) {
-		struct server_request *req = port->pending_replies;
+	while (req) {
 		int r = sendto(port->socket, req->response, req->response_len, 0,
 			   (struct sockaddr*) &req->addr, req->addrlen);
 		if (r < 0) {
@@ -1432,6 +1432,9 @@ server_port_flush(struct evdns_server_port *port)
 		if (server_request_free(req)) {
 			/* we released the last reference to req->port. */
 			return;
+		} else {
+			EVUTIL_ASSERT(req != port->pending_replies);
+			req = port->pending_replies;
 		}
 	}