void submit(RequestInfo requestInfo) throws Exception {
    if (isShutDown) {
      throw new ShutDownException();
    }
    maxParallelRequest.acquire();
    if (isShutDown) {
      maxParallelRequest.release();
      throw new ShutDownException();
    }
    requestInfos.offer(requestInfo);
  }
Adds the request info to the queue and ready for polling
@param requestInfo request info
@throws Exception
ambry-tools/src/main/java/com/github/ambry/tools/perf/serverperf/ServerPerfNetworkQueue.java