From 260e28ecadc654ce3f0a5b6c7058788235265574 Mon Sep 17 00:00:00 2001
From: gtully <gary.tully@gmail.com>
Date: Mon, 2 Mar 2015 14:09:58 +0000
Subject: [PATCH] https://issues.apache.org/jira/browse/AMQ-5620 - avoid
 potential deadlock on shutdown - waiting on connections to stop before
 stopping the pa would be an alternative but may block for ever, auto rollback
 ensures there is no need

---
 .../store/kahadb/disk/journal/Journal.java    | 29 +++++++++++--------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/disk/journal/Journal.java b/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/disk/journal/Journal.java
index 91f82aecef..54386cb730 100644
--- a/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/disk/journal/Journal.java
+++ b/activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/disk/journal/Journal.java
@@ -463,20 +463,25 @@ public class Journal {
         return dataFile.getNext();
     }
 
-    public synchronized void close() throws IOException {
-        if (!started) {
-            return;
+    public void close() throws IOException {
+        synchronized (this) {
+            if (!started) {
+                return;
+            }
+            if (this.timer != null) {
+                this.timer.cancel();
+            }
+            accessorPool.close();
         }
-        if (this.timer != null) {
-            this.timer.cancel();
-        }
-        accessorPool.close();
+        // the appender can be calling back to to the journal blocking a close AMQ-5620
         appender.close();
-        fileMap.clear();
-        fileByFileMap.clear();
-        dataFiles.clear();
-        lastAppendLocation.set(null);
-        started = false;
+        synchronized (this) {
+            fileMap.clear();
+            fileByFileMap.clear();
+            dataFiles.clear();
+            lastAppendLocation.set(null);
+            started = false;
+        }
     }
 
     protected synchronized void cleanup() {