Program: 89534
Project: 89534
Buggy source:
private Runnable getTransferScanTask(){
  return new Runnable(){
    @Override public void run(){
      try {
        if (s_logger.isTraceEnabled()) {
          s_logger.trace("String_Node_Str" + _nodeId);
        }
        if (_agentToTransferIds.size() > 0) {
          s_logger.debug("String_Node_Str" + _agentToTransferIds.size() + "String_Node_Str");
          for (          Long hostId : _agentToTransferIds) {
            AgentAttache attache=findAttache(hostId);
            Date cutTime=DateUtil.currentGMTTime();
            if (_hostTransferDao.isNotActive(hostId,new Date(cutTime.getTime() - rebalanceTimeOut))) {
              s_logger.debug("String_Node_Str" + hostId + "String_Node_Str");
              failStartRebalance(hostId);
              return;
            }
            HostTransferMapVO transferMap=_hostTransferDao.findByIdAndCurrentOwnerId(hostId,_nodeId);
            if (transferMap == null) {
              s_logger.debug("String_Node_Str" + hostId + "String_Node_Str");
              failStartRebalance(hostId);
              return;
            }
            ManagementServerHostVO ms=_mshostDao.findByMsid(transferMap.getFutureOwner());
            if (ms != null && ms.getState() != ManagementServerHost.State.Up) {
              s_logger.debug("String_Node_Str" + hostId + "String_Node_Str"+ ms+ "String_Node_Str");
              failStartRebalance(hostId);
              return;
            }
            if (attache.getQueueSize() == 0 && attache.getNonRecurringListenersSize() == 0) {
              rebalanceHost(hostId,transferMap.getInitialOwner(),transferMap.getFutureOwner());
            }
 else {
              s_logger.debug("String_Node_Str" + hostId + "String_Node_Str"+ attache.getQueueSize()+ "String_Node_Str"+ attache.getNonRecurringListenersSize());
            }
          }
        }
 else {
          if (s_logger.isTraceEnabled()) {
            s_logger.trace("String_Node_Str" + _nodeId);
          }
        }
      }
 catch (      Throwable e) {
        s_logger.error("String_Node_Str",e);
      }
    }
  }
;
}

Fixed version (ground truth):
private Runnable getTransferScanTask(){
  return new Runnable(){
    @Override public void run(){
      try {
        if (s_logger.isTraceEnabled()) {
          s_logger.trace("String_Node_Str" + _nodeId);
        }
synchronized (_agentToTransferIds) {
          if (_agentToTransferIds.size() > 0) {
            s_logger.debug("String_Node_Str" + _agentToTransferIds.size() + "String_Node_Str");
            for (Iterator<Long> iterator=_agentToTransferIds.iterator(); iterator.hasNext(); ) {
              Long hostId=iterator.next();
              AgentAttache attache=findAttache(hostId);
              Date cutTime=DateUtil.currentGMTTime();
              if (_hostTransferDao.isNotActive(hostId,new Date(cutTime.getTime() - rebalanceTimeOut))) {
                s_logger.debug("String_Node_Str" + hostId + "String_Node_Str");
                iterator.remove();
                _hostTransferDao.completeAgentTransfer(hostId);
                continue;
              }
              HostTransferMapVO transferMap=_hostTransferDao.findByIdAndCurrentOwnerId(hostId,_nodeId);
              if (transferMap == null) {
                s_logger.debug("String_Node_Str" + hostId + "String_Node_Str");
                iterator.remove();
                _hostTransferDao.completeAgentTransfer(hostId);
                continue;
              }
              ManagementServerHostVO ms=_mshostDao.findByMsid(transferMap.getFutureOwner());
              if (ms != null && ms.getState() != ManagementServerHost.State.Up) {
                s_logger.debug("String_Node_Str" + hostId + "String_Node_Str"+ ms+ "String_Node_Str");
                iterator.remove();
                _hostTransferDao.completeAgentTransfer(hostId);
                continue;
              }
              if (attache.getQueueSize() == 0 && attache.getNonRecurringListenersSize() == 0) {
                iterator.remove();
                rebalanceHost(hostId,transferMap.getInitialOwner(),transferMap.getFutureOwner());
              }
 else {
                s_logger.debug("String_Node_Str" + hostId + "String_Node_Str"+ attache.getQueueSize()+ "String_Node_Str"+ attache.getNonRecurringListenersSize());
              }
            }
          }
 else {
            if (s_logger.isTraceEnabled()) {
              s_logger.trace("String_Node_Str" + _nodeId);
            }
          }
        }
      }
 catch (      Throwable e) {
        s_logger.error("String_Node_Str",e);
      }
    }
  }
;
}