From: Willy Tarreau <w@1wt.eu>
Date: Tue, 1 Oct 2013 15:12:05 +0000 (+0200)
Subject: MEDIUM: stream-int: do not allocate a connection in parallel to applets
X-Git-Tag: v1.5-dev20~111
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ce9dbcd9ea2dd94bbc21f34fbb9ba7cebfa20e19;p=thirdparty%2Fhaproxy.git

MEDIUM: stream-int: do not allocate a connection in parallel to applets

When we know we're not going to use a connection on a stream interface
because we're using an applet instead, do not allocate a connection, or
release the preallocated one. We do that for peers and CLI only at the
moment, and not for HTTP stats which in the future might be adapted to
support keep-alive.

The connection pointer is simply set to NULL, which pool_free2() already
supports.
---

diff --git a/src/dumpstats.c b/src/dumpstats.c
index 6703b9be96..0df28829ed 100644
--- a/src/dumpstats.c
+++ b/src/dumpstats.c
@@ -156,7 +156,12 @@ extern const char *stat_status_codes[];
  */
 static int stats_accept(struct session *s)
 {
-	/* we have a dedicated I/O handler for the stats */
+	/* we have a dedicated I/O handler for the CLI/stats, so we can safely
+	 * release the pre-allocated connection that we will never use.
+	 */
+	pool_free2(pool2_connection, s->si[1].conn);
+	s->si[1].conn = NULL;
+
 	stream_int_register_handler(&s->si[1], &cli_applet);
 	s->target = &cli_applet.obj_type; // for logging only
 	s->si[1].appctx.st1 = 0;
diff --git a/src/peers.c b/src/peers.c
index 40936e45d1..6a1a8a4ae3 100644
--- a/src/peers.c
+++ b/src/peers.c
@@ -1083,7 +1083,12 @@ static void peer_session_forceshutdown(struct session * session)
  */
 int peer_accept(struct session *s)
 {
-	 /* we have a dedicated I/O handler for the stats */
+	/* we have a dedicated I/O handler for the peers, so we can safely
+	 * release the pre-allocated connection that we will never use.
+	 */
+	pool_free2(pool2_connection, s->si[1].conn);
+	s->si[1].conn = NULL;
+
 	stream_int_register_handler(&s->si[1], &peer_applet);
 	s->target = &peer_applet.obj_type; // for logging only
 	s->si[1].appctx.ctx.peers.ptr = s;
@@ -1123,9 +1128,6 @@ static struct session *peer_session_create(struct peer *peer, struct peer_sessio
 		goto out_close;
 	}
 
-	if (unlikely((s->si[0].conn = pool_alloc2(pool2_connection)) == NULL))
-		goto out_fail_conn0;
-
 	if (unlikely((s->si[1].conn = pool_alloc2(pool2_connection)) == NULL))
 		goto out_fail_conn1;
 
@@ -1161,13 +1163,7 @@ static struct session *peer_session_create(struct peer *peer, struct peer_sessio
 
 	s->req = s->rep = NULL; /* will be allocated later */
 
-	/* si[0] is the applet, we should not need s->si[0].conn anymore soon */
-	s->si[0].conn->obj_type = OBJ_TYPE_CONN;
-	s->si[0].conn->t.sock.fd = -1;
-	s->si[0].conn->flags = CO_FL_NONE;
-	s->si[0].conn->err_code = CO_ER_NONE;
-	s->si[0].conn->target = &l->obj_type;
-
+	s->si[0].conn = NULL;
 	s->si[0].owner = t;
 	s->si[0].state = s->si[0].prev_state = SI_ST_EST;
 	s->si[0].err_type = SI_ET_NONE;
@@ -1319,8 +1315,6 @@ static struct session *peer_session_create(struct peer *peer, struct peer_sessio
 	LIST_DEL(&s->list);
 	pool_free2(pool2_connection, s->si[1].conn);
  out_fail_conn1:
-	pool_free2(pool2_connection, s->si[0].conn);
- out_fail_conn0:
 	pool_free2(pool2_session, s);
  out_close:
 	return s;