From b876aa9f3495a9b4816fc1187ae058e50f1285df Mon Sep 17 00:00:00 2001
From: markt <markt@13f79535-47bb-0310-9956-ffa450edef68>
Date: Wed, 8 Jun 2011 15:52:26 +0000
Subject: [PATCH] Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=51340
 Fix thread-safety issue when parsing multiple web.xml files in parallel.
 Apache Tomcat does not do this but products that embed it may.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1133446 13f79535-47bb-0310-9956-ffa450edef68
---
 java/org/apache/catalina/startup/ContextConfig.java | 13 +++++++------
 webapps/docs/changelog.xml                          |  5 +++++
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/java/org/apache/catalina/startup/ContextConfig.java b/java/org/apache/catalina/startup/ContextConfig.java
index adecb5f49..ac396c981 100644
--- a/java/org/apache/catalina/startup/ContextConfig.java
+++ b/java/org/apache/catalina/startup/ContextConfig.java
@@ -1676,13 +1676,18 @@ public class ContextConfig
         // thread safe. Whilst there should only be one thread at a time
         // processing a config, play safe and sync.
         Digester digester;
+        WebRuleSet ruleSet;
         if (fragment) {
             digester = webFragmentDigester;
+            ruleSet = webFragmentRuleSet;
         } else {
             digester = webDigester;
+            ruleSet = webRuleSet;
         }
         
-        synchronized(digester) {
+        // Sync on the ruleSet since the same ruleSet is shared across all four
+        // digesters
+        synchronized(ruleSet) {
             
             digester.push(dest);
             digester.setErrorHandler(handler);
@@ -1713,11 +1718,7 @@ public class ContextConfig
                 ok = false;
             } finally {
                 digester.reset();
-                if (fragment) {
-                    webFragmentRuleSet.recycle();
-                } else {
-                    webRuleSet.recycle();
-                }
+                ruleSet.recycle();
             }
         }
     }
diff --git a/webapps/docs/changelog.xml b/webapps/docs/changelog.xml
index 34374e6a6..b42f0bced 100644
--- a/webapps/docs/changelog.xml
+++ b/webapps/docs/changelog.xml
@@ -71,6 +71,11 @@
         Avoid possible NPE when logging requests received during embedded Tomcat
         shutdown. (markt)
       </fix>
+      <fix>
+        <bug>51340</bug>: Fix thread-safety issue when parsing multiple web.xml
+        files in parallel. Apache Tomcat does not do this but products that
+        embed it may. (markt)
+      </fix>
     </changelog>
   </subsection>
   <subsection name="Coyote">
-- 
2.11.0