add active_queue feature: wait a bounded time for threads to progress with their tasks
add active_queue feature: wait a bounded time for threads to progress with their tasks

virtdb/virtdb-utils,virtdb/virtdb-utils,virtdb/virtdb-utils,starschema/virtdb-utils,starschema/virtdb-utils,starschema/virtdb-utils,virtdb/virtdb-utils,starschema/virtdb-utils