void _runWorkQueue()

in lib/src/driver/driver.dart [85:127]
28 lines of code
6 McCabe index (conditional complexity)

  void _runWorkQueue() {
    // Bail out conditions, we will continue to call ourselves indefinitely
    // until one of these is met.
    if (_workQueue.isEmpty) return;
    if (_numWorkers == _maxWorkers && _idleWorkers.isEmpty) return;
    if (_numWorkers > _maxWorkers) {
      throw StateError('Internal error, created to many workers. Please '
          'file a bug at https://github.com/dart-lang/bazel_worker/issues/new');
    }

    // At this point we definitely want to run a task, we just need to decide
    // whether or not we need to start up a new worker.
    var attempt = _workQueue.removeFirst();
    if (_idleWorkers.isNotEmpty) {
      _runWorker(_idleWorkers.removeLast(), attempt);
    } else {
      // No need to block here, we want to continue to synchronously drain the
      // work queue.
      var futureWorker = _spawnWorker();
      _spawningWorkers.add(futureWorker);
      futureWorker.then((worker) {
        _spawningWorkers.remove(futureWorker);
        _readyWorkers.add(worker);
        var connection = StdDriverConnection.forWorker(worker);
        _workerConnections[worker] = connection;
        _runWorker(worker, attempt);

        // When the worker exits we should retry running the work queue in case
        // there is more work to be done. This is primarily just a defensive
        // thing but is cheap to do.
        //
        // We don't use `exitCode` because it is null for detached processes (
        // which is common for workers).
        connection.done.then((_) {
          _idleWorkers.remove(worker);
          _readyWorkers.remove(worker);
          _runWorkQueue();
        });
      });
    }
    // Recursively calls itself until one of the bail out conditions are met.
    _runWorkQueue();
  }