From 5cb4823c4b98a0046cd779fd63acb2e2c03f75d6 Mon Sep 17 00:00:00 2001
From: ivanr <ivanr@9017d574-64ec-4062-9424-5e00b32a252b>
Date: Wed, 20 Jun 2007 10:59:37 +0000
Subject: [PATCH] Documented that we do not support atomic updates of
 persistent variables at this time.

---
 doc/modsecurity2-apache-reference.xml | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/doc/modsecurity2-apache-reference.xml b/doc/modsecurity2-apache-reference.xml
index cd98ca81..e80ee5a2 100644
--- a/doc/modsecurity2-apache-reference.xml
+++ b/doc/modsecurity2-apache-reference.xml
@@ -3630,6 +3630,17 @@ SecRule REQUEST_URI "^/cgi-bin/script\.pl" \
         moreinfo="none"> SESSION</literal>, and <literal
         moreinfo="none">USER</literal>.</para>
       </note>
+
+      <note>
+        <para>Please note that ModSecurity does not implement atomic updates
+        of persistent variables at this time. Variables are read from storage
+        whenever <literal>initcol</literal> is encountered in the rules and
+        persisted at the end of request processing. On busy servers requests
+        often run in parallel, leading to situations where one request
+        overwrites the changes made by another request. We anticipate
+        implementing atomic updates of counter values in a future
+        version.</para>
+      </note>
     </section>
 
     <section>