Package org.apache.sysds.runtime.controlprogram.parfor

Class LocalTaskQueue<T>

java.lang.Object
org.apache.sysds.runtime.controlprogram.parfor.LocalTaskQueue<T>
Direct Known Subclasses:
SubscribableTaskQueue
public class LocalTaskQueue<T> extends Object
This class provides a way of dynamic task distribution to multiple workers in local multi-threaded environments. Its main purpose is inter-thread communication for achieving dynamic load balancing. A good load balance between parallel workers is crucial with regard to the overall speedup of parallelization (see Amdahl's law). From a technical perspective, a thread monitor concept is used for blocking of waiting writers and readers. Synchronized writes and reads ensure that each task is only read by exactly one reader. Furthermore, the queue is implemented as a simple FIFO.

  • Field Details

  • Constructor Details

    • LocalTaskQueue

      public LocalTaskQueue()

  • Method Details

    • enqueueTask

      public void enqueueTask(T t) throws InterruptedException
      Synchronized insert of a new task to the end of the FIFO queue.
      Parameters:
      t - task
      Throws:
      InterruptedException - if InterruptedException occurs

    • dequeueTask

      public T dequeueTask() throws InterruptedException
      Synchronized read and delete from the top of the FIFO queue.
      Returns:
      task
      Throws:
      InterruptedException - if InterruptedException occurs

    • hasNext

      public boolean hasNext()

    • closeInput

      public void closeInput()
      Synchronized (logical) insert of a NO_MORE_TASKS symbol at the end of the FIFO queue in order to mark that no more tasks will be inserted into the queue.

    • isProcessed

      public boolean isProcessed()

    • propagateFailure

      public void propagateFailure(DMLRuntimeException failure)

    • toString

      public String toString()
      Overrides:
      toString in class Object