Package com.pnfsoftware.jeb.util.collect

Class AsyncEventQueue<E>

java.lang.Object
com.pnfsoftware.jeb.util.collect.AsyncEventQueue<E>
Type Parameters:
E - queued element type
Direct Known Subclasses:
DexDecompilerEventQueue
@Ser public class AsyncEventQueue<E> extends Object
Highly efficient, loosely bounded concurrent pseudo-queue for single-reader/multiple-writers scenarios. The implementation relies on ConcurrentLinkedQueue.

If the bound is reached, newest elements are dropped. To achieve high write efficiency and avoid locking, the queue is loosely bounded: under certain conditions, elements may be dropped although the queue did not reach its capacity; conversely, elements may be added although the queue reached its capacity. To lift this uncertainty, use a bound of Integer.MAX_VALUE. The writers should never never pull elements. Null elements are illegal.

  • Constructor Details

    • AsyncEventQueue

      public AsyncEventQueue()
      Create an unbounded queue.

    • AsyncEventQueue

      public AsyncEventQueue(int capacity)
      Create a queue, optionally bounded.
      Parameters:
      capacity - maximum queue capacity

  • Method Details

    • add

      public boolean add(E e)
      Add to the tail of the queue.
      Parameters:
      e - non-null entry to be enqueued
      Returns:
      true if the element was added, false if it was dropped

    • pull

      public E pull()
      Pull the head, unless the queue is empty, in which case null is returned.

      Implementation note: this method must not be used by producers; its use is reserved for the single consumer.

      Returns:
      the head or null

    • pullAll

      public List<E> pullAll()
      Pull all elements.
      Returns:
      pulled elements

    • readAll

      public List<E> readAll()
      Read all elements without clearing the queue.
      Returns:
      copy of queued elements

    • size

      public int size()
      Get the approximate queue size.
      Returns:
      current queue size

    • isEmpty

      public boolean isEmpty()
      Determine whether the queue is empty.
      Returns:
      true if the queue is empty

    • clear

      public void clear()
      Remove all queued elements.

    • toString

      public String toString()
      Overrides:
      toString in class Object