Syncronization. JM-605

git-svn-id: http://svn.igniterealtime.org/svn/repos/wildfire/trunk@3622 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/wildfire/group/GroupManager.java

@@ -210,6 +210,7 @@ public class GroupManager {
      * @return an unmodifiable Collection of all groups.
      */
     public Collection<Group> getGroups() {
+        synchronized (globalGroupKey) {
             Collection<Group> groups = userGroupCache.get(globalGroupKey);
             if (groups == null) {
                 groups = provider.getGroups();
@@ -219,6 +220,7 @@ public class GroupManager {
             }
             return groups;
         }
+    }
 
     /**
      * Returns an iterator for all groups according to a filter.
@@ -258,15 +260,18 @@ public class GroupManager {
      * @return all groups that an entity belongs to.
      */
     public Collection<Group> getGroups(JID user) {
-        Collection<Group> groups = userGroupCache.get(user);
+        String userID = user.toString();
+        synchronized (userID.intern()) {
+            Collection<Group> groups = userGroupCache.get(userID);
             if (groups == null) {
                 groups = provider.getGroups(user);
                 // Add to cache and ensure correct identity
                 groups = cacheAndEnsureIdentity(groups);
-            userGroupCache.put(user.toString(), groups);
+                userGroupCache.put(userID, groups);
             }
             return groups;
         }
+    }
 
     /**
      * Returns the configured group provider. Note that this method has special access