From: Paul Dokas <dokas@cs.umn.edu>
Subject: Fw: bin/25748: mozilla stopped working
Date: Tue, 1 Jun 2004 23:49:14 -0500

> Looking deeper into this with GDB, I noticed that there were about 10 running threads
> at the time of the crash.  And of those threads, about half appear to have been doing
> DNS lookups.
> 
> Is there any chance that the new resolver library is responsible for this?  Is it
> possible that it's not thread safe?  Or that there's something in the way that
> mozilla is calling the new library vs the old one?

There is a patch to prevent multiple DNS lookup simultaneously.
If your analysis is correct, problem is in "LOCK_DNS()".
But I don't known what "LOCK_DNS()" is doing actually.

$NetBSD: patch-br,v 1.3 2004/02/22 12:02:55 taya Exp $

--- nsprpub/pr/src/misc/prnetdb.c.orig	2004-02-19 21:45:15.000000000 +0900
+++ nsprpub/pr/src/misc/prnetdb.c	2004-02-19 21:50:57.000000000 +0900
@@ -2094,7 +2094,12 @@
          */
         hints.ai_socktype = SOCK_STREAM;
 
+        LOCK_DNS();
+
         rv = GETADDRINFO(hostname, NULL, &hints, &res);
+
+        UNLOCK_DNS();
+
         if (rv == 0)
             return (PRAddrInfo *) res;