From a88a513e3c91d65a311614ca84c9d2725d694bbe Mon Sep 17 00:00:00 2001
From: Gary Tully <gtully@apache.org>
Date: Wed, 10 Jun 2009 14:06:59 +0000
Subject: [PATCH] fix file lock usage in kahadb store, so shared file system
 master slave can work

git-svn-id: https://svn.apache.org/repos/asf/activemq/trunk@783364 13f79535-47bb-0310-9956-ffa450edef68
---
 .../org/apache/activemq/store/kahadb/MessageDatabase.java | 2 +-
 kahadb/src/main/java/org/apache/kahadb/util/LockFile.java | 8 +++++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/activemq-core/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java b/activemq-core/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java
index db4c838656..95b3f5e33a 100644
--- a/activemq-core/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java
+++ b/activemq-core/src/main/java/org/apache/activemq/store/kahadb/MessageDatabase.java
@@ -229,7 +229,7 @@ public class MessageDatabase {
 	                    lockFile.lock();
 	                    break;
 	                } catch (IOException e) {
-	                    LOG.info("Database "+lockFileName+" is locked... waiting " + (DATABASE_LOCKED_WAIT_DELAY / 1000) + " seconds for the database to be unlocked.");
+	                    LOG.info("Database "+lockFileName+" is locked... waiting " + (DATABASE_LOCKED_WAIT_DELAY / 1000) + " seconds for the database to be unlocked. Reason: " + e);
 	                    try {
 	                        Thread.sleep(DATABASE_LOCKED_WAIT_DELAY);
 	                    } catch (InterruptedException e1) {
diff --git a/kahadb/src/main/java/org/apache/kahadb/util/LockFile.java b/kahadb/src/main/java/org/apache/kahadb/util/LockFile.java
index c7338565ea..1d7b5b6ba3 100644
--- a/kahadb/src/main/java/org/apache/kahadb/util/LockFile.java
+++ b/kahadb/src/main/java/org/apache/kahadb/util/LockFile.java
@@ -50,8 +50,7 @@ public class LockFile {
             return;
         }
 
-        lockCounter++;
-        if( lockCounter!=1 ) {
+        if( lockCounter>0 ) {
             return;
         }
         
@@ -63,9 +62,12 @@ public class LockFile {
             } catch (OverlappingFileLockException e) {
                 throw IOExceptionSupport.create("File '" + file + "' could not be locked.",e);
             }
-            if (lock == null) {
+            if (lock != null) {
+                lockCounter++;
+            } else {
                 throw new IOException("File '" + file + "' could not be locked.");
             }
+              
         }
     }