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root/jsr166/jsr166/src/jsr166y/LinkedTransferQueue.java

Comparing jsr166/src/jsr166y/LinkedTransferQueue.java (file contents):
Revision 1.36 by jsr166, Fri Jul 31 07:30:29 2009 UTC vs.
Revision 1.44 by jsr166, Tue Aug 4 20:32:16 2009 UTC

#	Line 18 | Line 18 | import java.util.concurrent.locks.LockSu
18		import java.util.concurrent.atomic.AtomicReference;
19
20		/**
21	<	* An unbounded {@linkplain TransferQueue} based on linked nodes.
21	>	* An unbounded {@link TransferQueue} based on linked nodes.
22		* This queue orders elements FIFO (first-in-first-out) with respect
23		* to any given producer.  The <em>head</em> of the queue is that
24		* element that has been on the queue the longest time for some
#	Line 219 | Line 219 | public class LinkedTransferQueue<E> exte
219		Node<E> t = tail.get();
220		Node<E> h = head.get();
221
222	<	if (t != null && (t == h || t.isData == isData)) {
222	>	if (t == h || t.isData == isData) {
223		if (s == null)
224		s = new Node<E>(e, isData);
225		Node<E> last = t.next;
#	Line 231 | Line 231 | public class LinkedTransferQueue<E> exte
231		tail.compareAndSet(t, s);
232		return awaitFulfill(t, s, e, mode, nanos);
233		}
234	<	}
235	<
236	<	else if (h != null) {
234	>	} else {
235		Node<E> first = h.next;
236		if (t == tail.get() && first != null &&
237		advanceHead(h, first)) {
#	Line 261 | Line 259 | public class LinkedTransferQueue<E> exte
259		Node<E> t = tail.get();
260		Node<E> h = head.get();
261
262	<	if (t != null && (t == h || t.isData == isData)) {
262	>	if (t == h || t.isData == isData) {
263		Node<E> last = t.next;
264		if (t == tail.get()) {
265		if (last != null)
#	Line 269 | Line 267 | public class LinkedTransferQueue<E> exte
267		else
268		return null;
269		}
270	<	}
273	<	else if (h != null) {
270	>	} else {
271		Node<E> first = h.next;
272		if (t == tail.get() &&
273		first != null &&
#	Line 294 | Line 291 | public class LinkedTransferQueue<E> exte
291		* @param e the comparison value for checking match
292		* @param mode mode
293		* @param nanos timeout value
294	<	* @return matched item, or s if cancelled
294	>	* @return matched item, or null if cancelled
295		*/
296		private E awaitFulfill(Node<E> pred, Node<E> s, E e,
297		int mode, long nanos) {
#	Line 332 | Line 329 | public class LinkedTransferQueue<E> exte
329		}
330		if (spins < 0) {
331		Node<E> h = head.get(); // only spin if at head
332	<	spins = ((h != null && h.next == s) ?
333	<	((mode == TIMEOUT) ?
334	<	maxTimedSpins : maxUntimedSpins) : 0);
332	>	spins = ((h.next != s) ? 0 :
333	>	(mode == TIMEOUT) ? maxTimedSpins :
334	>	maxUntimedSpins);
335		}
336		if (spins > 0)
337		--spins;
#	Line 360 | Line 357 | public class LinkedTransferQueue<E> exte
357		for (;;) {
358		Node<E> h = head.get();
359		Node<E> first = h.next;
360	<	if (first != null && first.next == first) { // help advance
360	>	if (first != null && first.get() == first) { // help advance
361		advanceHead(h, first);
362		continue;
363		}
#	Line 511 | Line 508 | public class LinkedTransferQueue<E> exte
508
509		/**
510		* Inserts the specified element at the tail of this queue.
511	<	* As the queue is unbounded this method will never throw
511	>	* As the queue is unbounded, this method will never throw
512		* {@link IllegalStateException} or return {@code false}.
513		*
514		* @return {@code true} (as specified by {@link Collection#add})
#	Line 522 | Line 519 | public class LinkedTransferQueue<E> exte
519		}
520
521		/**
522	<	* Transfers the specified element immediately if there exists a
523	<	* consumer already waiting to receive it (in {@link #take} or
524	<	* timed {@link #poll(long,TimeUnit) poll}), otherwise
525	<	* returning {@code false} without enqueuing the element.
522	>	* Transfers the element to a waiting consumer immediately, if possible.
523	>	*
524	>	* <p>More precisely, transfers the specified element immediately
525	>	* if there exists a consumer already waiting to receive it (in
526	>	* {@link #take} or timed {@link #poll(long,TimeUnit) poll}),
527	>	* otherwise returning {@code false} without enqueuing the element.
528		*
529		* @throws NullPointerException if the specified element is null
530		*/
#	Line 535 | Line 534 | public class LinkedTransferQueue<E> exte
534		}
535
536		/**
537	<	* Inserts the specified element at the tail of this queue,
538	<	* waiting if necessary for the element to be received by a
539	<	* consumer invoking {@code take} or {@code poll}.
537	>	* Transfers the element to a consumer, waiting if necessary to do so.
538	>	*
539	>	* <p>More precisely, transfers the specified element immediately
540	>	* if there exists a consumer already waiting to receive it (in
541	>	* {@link #take} or timed {@link #poll(long,TimeUnit) poll}),
542	>	* else inserts the specified element at the tail of this queue
543	>	* and waits until the element is received by a consumer.
544		*
545		* @throws NullPointerException if the specified element is null
546		*/
#	Line 550 | Line 553 | public class LinkedTransferQueue<E> exte
553		}
554
555		/**
556	<	* Inserts the specified element at the tail of this queue,
557	<	* waiting up to the specified wait time for the element to be
558	<	* received by a consumer invoking {@code take} or {@code poll}.
556	>	* Transfers the element to a consumer if it is possible to do so
557	>	* before the timeout elapses.
558	>	*
559	>	* <p>More precisely, transfers the specified element immediately
560	>	* if there exists a consumer already waiting to receive it (in
561	>	* {@link #take} or timed {@link #poll(long,TimeUnit) poll}),
562	>	* else inserts the specified element at the tail of this queue
563	>	* and waits until the element is received by a consumer,
564	>	* returning {@code false} if the specified wait time elapses
565	>	* before the element can be transferred.
566		*
567		* @throws NullPointerException if the specified element is null
568		*/
#	Line 630 | Line 640 | public class LinkedTransferQueue<E> exte
640		for (;;) {
641		Node<E> t = tail.get();
642		Node<E> h = head.get();
643	<	if (h != null && t != null) {
644	<	Node<E> last = t.next;
645	<	Node<E> first = h.next;
646	<	if (t == tail.get()) {
647	<	if (last != null)
648	<	tail.compareAndSet(t, last);
649	<	else if (first != null) {
650	<	Object x = first.get();
651	<	if (x == first)
642	<	advanceHead(h, first);
643	<	else
644	<	return h;
645	<	}
643	>	Node<E> last = t.next;
644	>	Node<E> first = h.next;
645	>	if (t == tail.get()) {
646	>	if (last != null)
647	>	tail.compareAndSet(t, last);
648	>	else if (first != null) {
649	>	Object x = first.get();
650	>	if (x == first)
651	>	advanceHead(h, first);
652		else
653		return h;
654		}
655	+	else
656	+	return h;
657		}
658		reclean();
659		}
#	Line 749 | Line 757 | public class LinkedTransferQueue<E> exte
757		}
758		}
759
760	+	/**
761	+	* Returns {@code true} if this queue contains no elements.
762	+	*
763	+	* @return {@code true} if this queue contains no elements
764	+	*/
765		public boolean isEmpty() {
766		for (;;) {
767		Node<E> h = traversalHead();
#	Line 830 | Line 843 | public class LinkedTransferQueue<E> exte
843		}
844		}
845
846	+	/**
847	+	* Removes a single instance of the specified element from this queue,
848	+	* if it is present.  More formally, removes an element {@code e} such
849	+	* that {@code o.equals(e)}, if this queue contains one or more such
850	+	* elements.
851	+	* Returns {@code true} if this queue contained the specified element
852	+	* (or equivalently, if this queue changed as a result of the call).
853	+	*
854	+	* @param o element to be removed from this queue, if present
855	+	* @return {@code true} if this queue changed as a result of the call
856	+	*/
857		public boolean remove(Object o) {
858		if (o == null)
859		return false;

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