From: Willy Tarreau <w@1wt.eu>
Date: Tue, 30 Jun 2020 09:19:23 +0000 (+0200)
Subject: MINOR: mux-h2: avoid taking the toremove_lock in on dying tasks
X-Git-Tag: v2.2-dev12~45
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bd42e9257da0c66b8e1f77fa926073ea39b3d98a;p=thirdparty%2Fhaproxy.git

MINOR: mux-h2: avoid taking the toremove_lock in on dying tasks

If the owning task is already dying (context was destroyed by h2_takeover)
there's no point taking the lock then removing it later since all the code
in between is conditionned by a non-null context. Let's simplify this.
---

diff --git a/src/mux_h2.c b/src/mux_h2.c
index c6634c5b74..5fad272e78 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -3705,34 +3705,36 @@ static struct task *h2_timeout_task(struct task *t, void *context, unsigned shor
 
 	TRACE_ENTER(H2_EV_H2C_WAKE, h2c ? h2c->conn : NULL);
 
-	if (!expired && h2c) {
-		TRACE_DEVEL("leaving (not expired)", H2_EV_H2C_WAKE, h2c->conn);
-		return t;
-	}
+	if (h2c) {
+		if (!expired) {
+			TRACE_DEVEL("leaving (not expired)", H2_EV_H2C_WAKE, h2c->conn);
+			return t;
+		}
 
-	if (h2c && !h2c_may_expire(h2c)) {
-		/* we do still have streams but all of them are idle, waiting
-		 * for the data layer, so we must not enforce the timeout here.
-		 */
-		t->expire = TICK_ETERNITY;
-		return t;
-	}
+		if (!h2c_may_expire(h2c)) {
+			/* we do still have streams but all of them are idle, waiting
+			 * for the data layer, so we must not enforce the timeout here.
+			 */
+			t->expire = TICK_ETERNITY;
+			return t;
+		}
 
-	/* We're about to destroy the connection, so make sure nobody attempts
-	 * to steal it from us.
-	 */
-	HA_SPIN_LOCK(OTHER_LOCK, &idle_conns[tid].toremove_lock);
+		/* We're about to destroy the connection, so make sure nobody attempts
+		 * to steal it from us.
+		 */
+		HA_SPIN_LOCK(OTHER_LOCK, &idle_conns[tid].toremove_lock);
 
-	if (h2c && h2c->conn->flags & CO_FL_LIST_MASK)
-		MT_LIST_DEL(&h2c->conn->list);
+		if (h2c->conn->flags & CO_FL_LIST_MASK)
+			MT_LIST_DEL(&h2c->conn->list);
 
-	/* Somebody already stole the connection from us, so we should not
-	 * free it, we just have to free the task.
-	 */
-	if (!t->context)
-		h2c = NULL;
+		/* Somebody already stole the connection from us, so we should not
+		 * free it, we just have to free the task.
+		 */
+		if (!t->context)
+			h2c = NULL;
 
-	HA_SPIN_UNLOCK(OTHER_LOCK, &idle_conns[tid].toremove_lock);
+		HA_SPIN_UNLOCK(OTHER_LOCK, &idle_conns[tid].toremove_lock);
+	}
 
 	task_destroy(t);