From: phk <phk@d4fa192b-c00b-0410-8231-f00ffab90ce4>
Date: Wed, 3 Dec 2008 16:40:45 +0000 (+0000)
Subject: Resolve the remove/lookup race the simple way.
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7d367da92ed10fbc8f9ede14b08e452adb8060c1;p=varnish

Resolve the remove/lookup race the simple way.



git-svn-id: svn+ssh://projects.linpro.no/svn/varnish/trunk@3456 d4fa192b-c00b-0410-8231-f00ffab90ce4
---

diff --git a/varnish-cache/bin/varnishd/hash_critbit.c b/varnish-cache/bin/varnishd/hash_critbit.c
index f7986492..a328dc26 100644
--- a/varnish-cache/bin/varnishd/hash_critbit.c
+++ b/varnish-cache/bin/varnishd/hash_critbit.c
@@ -364,6 +364,7 @@ static struct objhead *
 hcb_lookup(const struct sess *sp, struct objhead *noh)
 {
 	struct objhead *oh;
+	unsigned u;
 	
 	assert(params->hash_sha256);
 	oh =  hcb_insert(&hcb_root, noh, 0);
@@ -371,14 +372,14 @@ hcb_lookup(const struct sess *sp, struct objhead *noh)
 		/* Assert that we didn't muck with the tree without lock */
 		assert(oh != noh);
 		Lck_Lock(&oh->mtx);
-		oh->refcnt++;
+		u = oh->refcnt;
+		if (u)
+			oh->refcnt++;
 		Lck_Unlock(&oh->mtx);
-		VSL_stats->hcb_nolock++;
-		if (0) {
-			fprintf(stderr, "%s %d\n", __func__, __LINE__);
-			dump(&hcb_root, stderr);
+		if (u) {
+			VSL_stats->hcb_nolock++;
+			return (oh);
 		}
-		return (oh);
 	}
 
 	/*