Fix OPENDJ-471. FIFOEntryCache may leave stalled data on low memory conditi...

Ludovic Poitou

16.45.2012 f44c8fc292c782bbbb739d5497db28a3dac0cf07

Fix OPENDJ-471. FIFOEntryCache may leave stalled data on low memory conditions.
Now, when low memory conditions are detected, the FIFOEntryCache removes the previous version of the updated entry if it exists, instead of just removing the first-in entry.

 opends/src/server/org/opends/server/extensions/FIFOEntryCache.java

@@ -23,7 +23,7 @@
 *
 *
 *      Copyright 2006-2008 Sun Microsystems, Inc.
 *      Portions Copyright 2011 ForgeRock AS
 *      Portions Copyright 2011-2012 ForgeRock AS
 */
package org.opends.server.extensions;

@@ -347,18 +347,38 @@
      long usedMemory = runtime.totalMemory() - runtime.freeMemory();
      if (usedMemory > maxAllowedMemory)
      {
        Iterator<CacheEntry> iterator = dnMap.values().iterator();
        if (iterator.hasNext())
        CacheEntry cachedEntry = dnMap.remove(entry.getDN());
        if (cachedEntry == null)
        {
          CacheEntry ce = iterator.next();
          iterator.remove();

          HashMap<Long,CacheEntry> m = idMap.get(ce.getBackend());
          if (m != null)
          // The current entry wasn't there, let's remove an existing entry.
          Iterator<CacheEntry> iterator = dnMap.values().iterator();
          if (iterator.hasNext())
          {
            m.remove(ce.getEntryID());
            CacheEntry ce = iterator.next();
            iterator.remove();

            HashMap<Long,CacheEntry> m = idMap.get(ce.getBackend());
            if (m != null)
            {
              m.remove(ce.getEntryID());
            }
          }
        }
        else
        {
          // Try to remove the entry from the ID list as well.
          Map<Long,CacheEntry> map = idMap.get(backend);
          if (map != null)
          {
            map.remove(cacheEntry.getEntryID());
            // If this backend becomes empty now remove it from the idMap map.
            if (map.isEmpty())
            {
              idMap.remove(backend);
            }
          }
        }

      }
      else
      {