From b3c30403853dcc1e8c1e3e2177ad8f9d4eee1441 Mon Sep 17 00:00:00 2001
From: markt <markt@13f79535-47bb-0310-9956-ffa450edef68>
Date: Tue, 16 Nov 2010 17:13:29 +0000
Subject: [PATCH] Session manager performance Narrow sync - few % improvement

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1035699 13f79535-47bb-0310-9956-ffa450edef68
---
 java/org/apache/catalina/session/ManagerBase.java | 8 +++++---
 test/org/apache/catalina/session/Benchmarks.java  | 8 ++++----
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/java/org/apache/catalina/session/ManagerBase.java b/java/org/apache/catalina/session/ManagerBase.java
index 4b2acd5f8..08c60faac 100644
--- a/java/org/apache/catalina/session/ManagerBase.java
+++ b/java/org/apache/catalina/session/ManagerBase.java
@@ -980,7 +980,7 @@ public abstract class ManagerBase extends LifecycleMBeanBase
     /**
      * Generate and return a new session identifier.
      */
-    protected synchronized String generateSessionId() {
+    protected String generateSessionId() {
 
         byte random[] = new byte[16];
         String jvmRoute = getJvmRoute();
@@ -996,8 +996,10 @@ public abstract class ManagerBase extends LifecycleMBeanBase
             }
 
             while (resultLenBytes < this.sessionIdLength) {
-                getRandomBytes(random);
-                random = getDigest().digest(random);
+                synchronized (this) {
+                    getRandomBytes(random);
+                    random = getDigest().digest(random);
+                }
                 for (int j = 0;
                 j < random.length && resultLenBytes < this.sessionIdLength;
                 j++) {
diff --git a/test/org/apache/catalina/session/Benchmarks.java b/test/org/apache/catalina/session/Benchmarks.java
index 99dd1d68e..53d98f975 100644
--- a/test/org/apache/catalina/session/Benchmarks.java
+++ b/test/org/apache/catalina/session/Benchmarks.java
@@ -108,10 +108,10 @@ public class Benchmarks extends TestCase {
     
     /*
      * Results on markt's 4-core dev box
-     *  1 thread  -  2,422ms
-     *  2 threads -  5,047ms
-     *  4 threads - 13,188ms
-     * 16 threads - 54,422ms
+     *  1 thread  -  ~2,400ms
+     *  2 threads -  ~4,700ms
+     *  4 threads - ~12,600ms
+     * 16 threads - ~53,700ms
      */
     public void testManagerBaseCreateSession() {
         doTestManagerBaseCreateSession(1, 100000);
-- 
2.11.0