OID WriteBackManager::queueWriteBack( const string& remote , BSONObjBuilder& b ) { static mongo::mutex writebackIDOrdering( "WriteBackManager::queueWriteBack id ordering" ); scoped_lock lk( writebackIDOrdering ); OID writebackID; writebackID.initSequential(); b.append( "id", writebackID ); getWritebackQueue( remote )->queue.push( b.obj() ); return writebackID; }