# Class: com.pnfsoftware.jeb.util.collect.AsyncEventQueue Highly efficient, loosely bounded concurrent pseudo\-queue for single\-reader/multiple\-writers scenarios. The implementation relies on [ConcurrentLinkedQueue](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](Integer#MAX_VALUE). The writers should never never pull elements. Null elements are illegal. ## Constructor: AsyncEventQueue Description: Create an unbounded queue. ## Constructor: AsyncEventQueue - parameter: `capacity`, type: `int` Description: Create a queue, optionally bounded. parameter: capacity: maximum queue capacity ## Method: add - parameter: `e`, type: `E` - return type: `boolean` Description: Add to the tail of the queue. parameter: e: non\-null entry to be enqueued return: true if the element was added, false if it was dropped ## Method: clear Description: Remove all queued elements. ## Method: isEmpty - return type: `boolean` Description: Determine whether the queue is empty. return: true if the queue is empty ## Method: pull - return type: `E` Description: 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. return: the head or null ## Method: pullAll - return type: `java.util.List` Description: Pull all elements. return: pulled elements ## Method: readAll - return type: `java.util.List` Description: Read all elements without clearing the queue. return: copy of queued elements ## Method: size - return type: `int` Description: Get the approximate queue size. return: current queue size ## Method: toString - return type: `java.lang.String`