Package akka.dispatch

Interface BatchingExecutor

  • All Superinterfaces:
    All Known Implementing Classes:
    CallingThreadDispatcher, Dispatcher, ExecutionContexts.sameThreadExecutionContext$, MessageDispatcher, PinnedDispatcher

    public interface BatchingExecutor
    extends java.util.concurrent.Executor

    Mixin trait for an Executor which groups multiple nested calls into a single Runnable passed to the original Executor. This can be a useful optimization because it bypasses the original context's task queue and keeps related (nested) code on a single thread which may improve CPU affinity. However, if tasks passed to the Executor are blocking or expensive, this optimization can prevent work-stealing and make performance worse. Also, some ExecutionContext may be fast enough natively that this optimization just adds overhead. The default is already batching or fast enough not to benefit from it; while fromExecutor and fromExecutorService do NOT add this optimization since they don't know whether the underlying executor will benefit from it. A batching executor can create deadlocks if code does not use scala.concurrent.blocking when it should, because tasks created within other tasks will block on the outer task completing. This executor may run tasks in any order, including LIFO order. There are no ordering guarantees.

    WARNING: The underlying Executor's execute-method must not execute the submitted Runnable in the calling thread synchronously. It must enqueue/handoff the Runnable.

    • Method Detail

      • batchable

        boolean batchable​(java.lang.Runnable runnable)
        Override this to define which runnables will be batched.
      • execute

        void execute​(java.lang.Runnable runnable)
        Specified by:
        execute in interface java.util.concurrent.Executor
      • resubmitOnBlock

        boolean resubmitOnBlock()
      • unbatchedExecute

        void unbatchedExecute​(java.lang.Runnable r)