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Comparing jsr166/src/main/java/util/PriorityQueue.java (file contents):
Revision 1.63 by jsr166, Tue Mar 7 07:11:39 2006 UTC vs.
Revision 1.125 by jsr166, Sun May 6 21:07:41 2018 UTC

#	Line 1 | Line 1
1		/*
2	<	* %W% %E%
2	>	* Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
3	>	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4		*
5	<	* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
6	<	* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
5	>	* This code is free software; you can redistribute it and/or modify it
6	>	* under the terms of the GNU General Public License version 2 only, as
7	>	* published by the Free Software Foundation.  Oracle designates this
8	>	* particular file as subject to the "Classpath" exception as provided
9	>	* by Oracle in the LICENSE file that accompanied this code.
10	>	*
11	>	* This code is distributed in the hope that it will be useful, but WITHOUT
12	>	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13	>	* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14	>	* version 2 for more details (a copy is included in the LICENSE file that
15	>	* accompanied this code).
16	>	*
17	>	* You should have received a copy of the GNU General Public License version
18	>	* 2 along with this work; if not, write to the Free Software Foundation,
19	>	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20	>	*
21	>	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22	>	* or visit www.oracle.com if you need additional information or have any
23	>	* questions.
24		*/
25
26		package java.util;
27
28	+	import java.util.function.Consumer;
29	+	import jdk.internal.misc.SharedSecrets;
30	+
31		/**
32		* An unbounded priority {@linkplain Queue queue} based on a priority heap.
33		* The elements of the priority queue are ordered according to their
#	Line 34 | Line 55 | package java.util;
55		* <p>This class and its iterator implement all of the
56		* <em>optional</em> methods of the {@link Collection} and {@link
57		* Iterator} interfaces.  The Iterator provided in method {@link
58	<	* #iterator()} is <em>not</em> guaranteed to traverse the elements of
58	>	* #iterator()} and the Spliterator provided in method {@link #spliterator()}
59	>	* are <em>not</em> guaranteed to traverse the elements of
60		* the priority queue in any particular order. If you need ordered
61		* traversal, consider using {@code Arrays.sort(pq.toArray())}.
62		*
63	<	* <p> <strong>Note that this implementation is not synchronized.</strong>
63	>	* <p><strong>Note that this implementation is not synchronized.</strong>
64		* Multiple threads should not access a {@code PriorityQueue}
65		* instance concurrently if any of the threads modifies the queue.
66		* Instead, use the thread-safe {@link
67		* java.util.concurrent.PriorityBlockingQueue} class.
68		*
69		* <p>Implementation note: this implementation provides
70	<	* O(log(n)) time for the enqueing and dequeing methods
70	>	* O(log(n)) time for the enqueuing and dequeuing methods
71		* ({@code offer}, {@code poll}, {@code remove()} and {@code add});
72		* linear time for the {@code remove(Object)} and {@code contains(Object)}
73		* methods; and constant time for the retrieval methods
74		* ({@code peek}, {@code element}, and {@code size}).
75		*
76		* <p>This class is a member of the
77	<	* <a href="{@docRoot}/../guide/collections/index.html">
77	>	* <a href="{@docRoot}/java/util/package-summary.html#CollectionsFramework">
78		* Java Collections Framework</a>.
79		*
80		* @since 1.5
59	–	* @version %I%, %G%
81		* @author Josh Bloch, Doug Lea
82	<	* @param <E> the type of elements held in this collection
82	>	* @param <E> the type of elements held in this queue
83		*/
84	+	@SuppressWarnings("unchecked")
85		public class PriorityQueue<E> extends AbstractQueue<E>
86		implements java.io.Serializable {
87
#	Line 75 | Line 97 | public class PriorityQueue<E> extends Ab
97		* heap and each descendant d of n, n <= d.  The element with the
98		* lowest value is in queue[0], assuming the queue is nonempty.
99		*/
100	<	private transient Object[] queue;
100	>	transient Object[] queue; // non-private to simplify nested class access
101
102		/**
103		* The number of elements in the priority queue.
104		*/
105	<	private int size = 0;
105	>	int size;
106
107		/**
108		* The comparator, or null if priority queue uses elements'
#	Line 92 | Line 114 | public class PriorityQueue<E> extends Ab
114		* The number of times this priority queue has been
115		* <i>structurally modified</i>.  See AbstractList for gory details.
116		*/
117	<	private transient int modCount = 0;
117	>	transient int modCount;     // non-private to simplify nested class access
118
119		/**
120		* Creates a {@code PriorityQueue} with the default initial
#	Line 117 | Line 139 | public class PriorityQueue<E> extends Ab
139		}
140
141		/**
142	+	* Creates a {@code PriorityQueue} with the default initial capacity and
143	+	* whose elements are ordered according to the specified comparator.
144	+	*
145	+	* @param  comparator the comparator that will be used to order this
146	+	*         priority queue.  If {@code null}, the {@linkplain Comparable
147	+	*         natural ordering} of the elements will be used.
148	+	* @since 1.8
149	+	*/
150	+	public PriorityQueue(Comparator<? super E> comparator) {
151	+	this(DEFAULT_INITIAL_CAPACITY, comparator);
152	+	}
153	+
154	+	/**
155		* Creates a {@code PriorityQueue} with the specified initial capacity
156		* that orders its elements according to the specified comparator.
157		*
#	Line 154 | Line 189 | public class PriorityQueue<E> extends Ab
189		*         of its elements are null
190		*/
191		public PriorityQueue(Collection<? extends E> c) {
192	<	initFromCollection(c);
193	<	if (c instanceof SortedSet)
194	<	comparator = (Comparator<? super E>)
195	<	((SortedSet<? extends E>)c).comparator();
196	<	else if (c instanceof PriorityQueue)
197	<	comparator = (Comparator<? super E>)
198	<	((PriorityQueue<? extends E>)c).comparator();
192	>	if (c instanceof SortedSet<?>) {
193	>	SortedSet<? extends E> ss = (SortedSet<? extends E>) c;
194	>	this.comparator = (Comparator<? super E>) ss.comparator();
195	>	initElementsFromCollection(ss);
196	>	}
197	>	else if (c instanceof PriorityQueue<?>) {
198	>	PriorityQueue<? extends E> pq = (PriorityQueue<? extends E>) c;
199	>	this.comparator = (Comparator<? super E>) pq.comparator();
200	>	initFromPriorityQueue(pq);
201	>	}
202		else {
203	<	comparator = null;
204	<	heapify();
203	>	this.comparator = null;
204	>	initFromCollection(c);
205		}
206		}
207
#	Line 182 | Line 220 | public class PriorityQueue<E> extends Ab
220		*         of its elements are null
221		*/
222		public PriorityQueue(PriorityQueue<? extends E> c) {
223	<	comparator = (Comparator<? super E>)c.comparator();
224	<	initFromCollection(c);
223	>	this.comparator = (Comparator<? super E>) c.comparator();
224	>	initFromPriorityQueue(c);
225		}
226
227		/**
#	Line 200 | Line 238 | public class PriorityQueue<E> extends Ab
238		*         of its elements are null
239		*/
240		public PriorityQueue(SortedSet<? extends E> c) {
241	<	comparator = (Comparator<? super E>)c.comparator();
242	<	initFromCollection(c);
241	>	this.comparator = (Comparator<? super E>) c.comparator();
242	>	initElementsFromCollection(c);
243	>	}
244	>
245	>	/** Ensures that queue[0] exists, helping peek() and poll(). */
246	>	private static Object[] ensureNonEmpty(Object[] es) {
247	>	return (es.length > 0) ? es : new Object[1];
248	>	}
249	>
250	>	private void initFromPriorityQueue(PriorityQueue<? extends E> c) {
251	>	if (c.getClass() == PriorityQueue.class) {
252	>	this.queue = ensureNonEmpty(c.toArray());
253	>	this.size = c.size();
254	>	} else {
255	>	initFromCollection(c);
256	>	}
257	>	}
258	>
259	>	private void initElementsFromCollection(Collection<? extends E> c) {
260	>	Object[] es = c.toArray();
261	>	int len = es.length;
262	>	// If c.toArray incorrectly doesn't return Object[], copy it.
263	>	if (es.getClass() != Object[].class)
264	>	es = Arrays.copyOf(es, len, Object[].class);
265	>	if (len == 1 || this.comparator != null)
266	>	for (Object e : es)
267	>	if (e == null)
268	>	throw new NullPointerException();
269	>	this.queue = ensureNonEmpty(es);
270	>	this.size = len;
271		}
272
273		/**
#	Line 210 | Line 276 | public class PriorityQueue<E> extends Ab
276		* @param c the collection
277		*/
278		private void initFromCollection(Collection<? extends E> c) {
279	<	Object[] a = c.toArray();
280	<	// If c.toArray incorrectly doesn't return Object[], copy it.
215	<	if (a.getClass() != Object[].class)
216	<	a = Arrays.copyOf(a, a.length, Object[].class);
217	<	queue = a;
218	<	size = a.length;
279	>	initElementsFromCollection(c);
280	>	heapify();
281		}
282
283		/**
284	+	* The maximum size of array to allocate.
285	+	* Some VMs reserve some header words in an array.
286	+	* Attempts to allocate larger arrays may result in
287	+	* OutOfMemoryError: Requested array size exceeds VM limit
288	+	*/
289	+	private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8;
290	+
291	+	/**
292		* Increases the capacity of the array.
293		*
294		* @param minCapacity the desired minimum capacity
295		*/
296		private void grow(int minCapacity) {
297	<	if (minCapacity < 0) // overflow
228	<	throw new OutOfMemoryError();
229	<	int oldCapacity = queue.length;
297	>	int oldCapacity = queue.length;
298		// Double size if small; else grow by 50%
299	<	int newCapacity = ((oldCapacity < 64)?
300	<	((oldCapacity + 1) * 2):
301	<	((oldCapacity / 2) * 3));
302	<	if (newCapacity < 0) // overflow
303	<	newCapacity = Integer.MAX_VALUE;
304	<	if (newCapacity < minCapacity)
237	<	newCapacity = minCapacity;
299	>	int newCapacity = oldCapacity + ((oldCapacity < 64) ?
300	>	(oldCapacity + 2) :
301	>	(oldCapacity >> 1));
302	>	// overflow-conscious code
303	>	if (newCapacity - MAX_ARRAY_SIZE > 0)
304	>	newCapacity = hugeCapacity(minCapacity);
305		queue = Arrays.copyOf(queue, newCapacity);
306		}
307
308	+	private static int hugeCapacity(int minCapacity) {
309	+	if (minCapacity < 0) // overflow
310	+	throw new OutOfMemoryError();
311	+	return (minCapacity > MAX_ARRAY_SIZE) ?
312	+	Integer.MAX_VALUE :
313	+	MAX_ARRAY_SIZE;
314	+	}
315	+
316		/**
317		* Inserts the specified element into this priority queue.
318		*
#	Line 267 | Line 342 | public class PriorityQueue<E> extends Ab
342		int i = size;
343		if (i >= queue.length)
344		grow(i + 1);
345	+	siftUp(i, e);
346		size = i + 1;
271	–	if (i == 0)
272	–	queue[0] = e;
273	–	else
274	–	siftUp(i, e);
347		return true;
348		}
349
350		public E peek() {
279	–	if (size == 0)
280	–	return null;
351		return (E) queue[0];
352		}
353
354		private int indexOf(Object o) {
355	<	if (o != null) {
356	<	for (int i = 0; i < size; i++)
357	<	if (o.equals(queue[i]))
355	>	if (o != null) {
356	>	final Object[] es = queue;
357	>	for (int i = 0, n = size; i < n; i++)
358	>	if (o.equals(es[i]))
359		return i;
360		}
361		return -1;
#	Line 302 | Line 373 | public class PriorityQueue<E> extends Ab
373		* @return {@code true} if this queue changed as a result of the call
374		*/
375		public boolean remove(Object o) {
376	<	int i = indexOf(o);
377	<	if (i == -1)
378	<	return false;
379	<	else {
380	<	removeAt(i);
381	<	return true;
382	<	}
376	>	int i = indexOf(o);
377	>	if (i == -1)
378	>	return false;
379	>	else {
380	>	removeAt(i);
381	>	return true;
382	>	}
383		}
384
385		/**
386	<	* Version of remove using reference equality, not equals.
316	<	* Needed by iterator.remove.
386	>	* Identity-based version for use in Itr.remove.
387		*
388		* @param o element to be removed from this queue, if present
319	–	* @return {@code true} if removed
389		*/
390	<	boolean removeEq(Object o) {
391	<	for (int i = 0; i < size; i++) {
392	<	if (o == queue[i]) {
390	>	void removeEq(Object o) {
391	>	final Object[] es = queue;
392	>	for (int i = 0, n = size; i < n; i++) {
393	>	if (o == es[i]) {
394		removeAt(i);
395	<	return true;
395	>	break;
396		}
397		}
328	–	return false;
398		}
399
400		/**
#	Line 337 | Line 406 | public class PriorityQueue<E> extends Ab
406		* @return {@code true} if this queue contains the specified element
407		*/
408		public boolean contains(Object o) {
409	<	return indexOf(o) != -1;
409	>	return indexOf(o) >= 0;
410		}
411
412		/**
#	Line 375 | Line 444 | public class PriorityQueue<E> extends Ab
444		* precise control over the runtime type of the output array, and may,
445		* under certain circumstances, be used to save allocation costs.
446		*
447	<	* <p>Suppose <tt>x</tt> is a queue known to contain only strings.
447	>	* <p>Suppose {@code x} is a queue known to contain only strings.
448		* The following code can be used to dump the queue into a newly
449	<	* allocated array of <tt>String</tt>:
449	>	* allocated array of {@code String}:
450		*
451	<	* <pre>
383	<	*     String[] y = x.toArray(new String[0]);</pre>
451	>	* <pre> {@code String[] y = x.toArray(new String[0]);}</pre>
452		*
453	<	* Note that <tt>toArray(new Object[0])</tt> is identical in function to
454	<	* <tt>toArray()</tt>.
453	>	* Note that {@code toArray(new Object[0])} is identical in function to
454	>	* {@code toArray()}.
455		*
456		* @param a the array into which the elements of the queue are to
457		*          be stored, if it is big enough; otherwise, a new array of the
#	Line 395 | Line 463 | public class PriorityQueue<E> extends Ab
463		* @throws NullPointerException if the specified array is null
464		*/
465		public <T> T[] toArray(T[] a) {
466	+	final int size = this.size;
467		if (a.length < size)
468		// Make a new array of a's runtime type, but my contents:
469		return (T[]) Arrays.copyOf(queue, size, a.getClass());
470	<	System.arraycopy(queue, 0, a, 0, size);
470	>	System.arraycopy(queue, 0, a, 0, size);
471		if (a.length > size)
472		a[size] = null;
473		return a;
#	Line 419 | Line 488 | public class PriorityQueue<E> extends Ab
488		* Index (into queue array) of element to be returned by
489		* subsequent call to next.
490		*/
491	<	private int cursor = 0;
491	>	private int cursor;
492
493		/**
494		* Index of element returned by most recent call to next,
#	Line 439 | Line 508 | public class PriorityQueue<E> extends Ab
508		* We expect that most iterations, even those involving removals,
509		* will not need to store elements in this field.
510		*/
511	<	private ArrayDeque<E> forgetMeNot = null;
511	>	private ArrayDeque<E> forgetMeNot;
512
513		/**
514		* Element returned by the most recent call to next iff that
515		* element was drawn from the forgetMeNot list.
516		*/
517	<	private E lastRetElt = null;
517	>	private E lastRetElt;
518
519		/**
520		* The modCount value that the iterator believes that the backing
#	Line 454 | Line 523 | public class PriorityQueue<E> extends Ab
523		*/
524		private int expectedModCount = modCount;
525
526	+	Itr() {}                        // prevent access constructor creation
527	+
528		public boolean hasNext() {
529		return cursor < size ||
530		(forgetMeNot != null && !forgetMeNot.isEmpty());
#	Line 483 | Line 554 | public class PriorityQueue<E> extends Ab
554		cursor--;
555		else {
556		if (forgetMeNot == null)
557	<	forgetMeNot = new ArrayDeque<E>();
557	>	forgetMeNot = new ArrayDeque<>();
558		forgetMeNot.add(moved);
559		}
560		} else if (lastRetElt != null) {
#	Line 491 | Line 562 | public class PriorityQueue<E> extends Ab
562		lastRetElt = null;
563		} else {
564		throw new IllegalStateException();
565	<	}
565	>	}
566		expectedModCount = modCount;
567		}
568		}
#	Line 506 | Line 577 | public class PriorityQueue<E> extends Ab
577		*/
578		public void clear() {
579		modCount++;
580	<	for (int i = 0; i < size; i++)
581	<	queue[i] = null;
580	>	final Object[] es = queue;
581	>	for (int i = 0, n = size; i < n; i++)
582	>	es[i] = null;
583		size = 0;
584		}
585
586		public E poll() {
587	<	if (size == 0)
588	<	return null;
589	<	int s = --size;
590	<	modCount++;
591	<	E result = (E) queue[0];
592	<	E x = (E) queue[s];
593	<	queue[s] = null;
594	<	if (s != 0)
595	<	siftDown(0, x);
587	>	final Object[] es;
588	>	final E result;
589	>
590	>	if ((result = (E) ((es = queue)[0])) != null) {
591	>	modCount++;
592	>	final int n;
593	>	final E x = (E) es[(n = --size)];
594	>	es[n] = null;
595	>	if (n > 0) {
596	>	final Comparator<? super E> cmp;
597	>	if ((cmp = comparator) == null)
598	>	siftDownComparable(0, x, es, n);
599	>	else
600	>	siftDownUsingComparator(0, x, es, n, cmp);
601	>	}
602	>	}
603		return result;
604		}
605
#	Line 536 | Line 615 | public class PriorityQueue<E> extends Ab
615		* position before i. This fact is used by iterator.remove so as to
616		* avoid missing traversing elements.
617		*/
618	<	private E removeAt(int i) {
619	<	assert i >= 0 && i < size;
618	>	E removeAt(int i) {
619	>	// assert i >= 0 && i < size;
620		modCount++;
621		int s = --size;
622		if (s == i) // removed last element
#	Line 560 | Line 639 | public class PriorityQueue<E> extends Ab
639		* promoting x up the tree until it is greater than or equal to
640		* its parent, or is the root.
641		*
642	<	* To simplify and speed up coercions and comparisons. the
642	>	* To simplify and speed up coercions and comparisons, the
643		* Comparable and Comparator versions are separated into different
644		* methods that are otherwise identical. (Similarly for siftDown.)
645		*
#	Line 569 | Line 648 | public class PriorityQueue<E> extends Ab
648		*/
649		private void siftUp(int k, E x) {
650		if (comparator != null)
651	<	siftUpUsingComparator(k, x);
651	>	siftUpUsingComparator(k, x, queue, comparator);
652		else
653	<	siftUpComparable(k, x);
653	>	siftUpComparable(k, x, queue);
654		}
655
656	<	private void siftUpComparable(int k, E x) {
657	<	Comparable<? super E> key = (Comparable<? super E>) x;
656	>	private static <T> void siftUpComparable(int k, T x, Object[] es) {
657	>	Comparable<? super T> key = (Comparable<? super T>) x;
658		while (k > 0) {
659		int parent = (k - 1) >>> 1;
660	<	Object e = queue[parent];
661	<	if (key.compareTo((E) e) >= 0)
660	>	Object e = es[parent];
661	>	if (key.compareTo((T) e) >= 0)
662		break;
663	<	queue[k] = e;
663	>	es[k] = e;
664		k = parent;
665		}
666	<	queue[k] = key;
666	>	es[k] = key;
667		}
668
669	<	private void siftUpUsingComparator(int k, E x) {
669	>	private static <T> void siftUpUsingComparator(
670	>	int k, T x, Object[] es, Comparator<? super T> cmp) {
671		while (k > 0) {
672		int parent = (k - 1) >>> 1;
673	<	Object e = queue[parent];
674	<	if (comparator.compare(x, (E) e) >= 0)
673	>	Object e = es[parent];
674	>	if (cmp.compare(x, (T) e) >= 0)
675		break;
676	<	queue[k] = e;
676	>	es[k] = e;
677		k = parent;
678		}
679	<	queue[k] = x;
679	>	es[k] = x;
680		}
681
682		/**
#	Line 609 | Line 689 | public class PriorityQueue<E> extends Ab
689		*/
690		private void siftDown(int k, E x) {
691		if (comparator != null)
692	<	siftDownUsingComparator(k, x);
692	>	siftDownUsingComparator(k, x, queue, size, comparator);
693		else
694	<	siftDownComparable(k, x);
694	>	siftDownComparable(k, x, queue, size);
695		}
696
697	<	private void siftDownComparable(int k, E x) {
698	<	Comparable<? super E> key = (Comparable<? super E>)x;
699	<	int half = size >>> 1;        // loop while a non-leaf
697	>	private static <T> void siftDownComparable(int k, T x, Object[] es, int n) {
698	>	// assert n > 0;
699	>	Comparable<? super T> key = (Comparable<? super T>)x;
700	>	int half = n >>> 1;           // loop while a non-leaf
701		while (k < half) {
702		int child = (k << 1) + 1; // assume left child is least
703	<	Object c = queue[child];
703	>	Object c = es[child];
704		int right = child + 1;
705	<	if (right < size &&
706	<	((Comparable<? super E>) c).compareTo((E) queue[right]) > 0)
707	<	c = queue[child = right];
708	<	if (key.compareTo((E) c) <= 0)
705	>	if (right < n &&
706	>	((Comparable<? super T>) c).compareTo((T) es[right]) > 0)
707	>	c = es[child = right];
708	>	if (key.compareTo((T) c) <= 0)
709		break;
710	<	queue[k] = c;
710	>	es[k] = c;
711		k = child;
712		}
713	<	queue[k] = key;
713	>	es[k] = key;
714		}
715
716	<	private void siftDownUsingComparator(int k, E x) {
717	<	int half = size >>> 1;
716	>	private static <T> void siftDownUsingComparator(
717	>	int k, T x, Object[] es, int n, Comparator<? super T> cmp) {
718	>	// assert n > 0;
719	>	int half = n >>> 1;
720		while (k < half) {
721		int child = (k << 1) + 1;
722	<	Object c = queue[child];
722	>	Object c = es[child];
723		int right = child + 1;
724	<	if (right < size &&
725	<	comparator.compare((E) c, (E) queue[right]) > 0)
726	<	c = queue[child = right];
644	<	if (comparator.compare(x, (E) c) <= 0)
724	>	if (right < n && cmp.compare((T) c, (T) es[right]) > 0)
725	>	c = es[child = right];
726	>	if (cmp.compare(x, (T) c) <= 0)
727		break;
728	<	queue[k] = c;
728	>	es[k] = c;
729		k = child;
730		}
731	<	queue[k] = x;
731	>	es[k] = x;
732		}
733
734		/**
735		* Establishes the heap invariant (described above) in the entire tree,
736		* assuming nothing about the order of the elements prior to the call.
737	+	* This classic algorithm due to Floyd (1964) is known to be O(size).
738		*/
739		private void heapify() {
740	<	for (int i = (size >>> 1) - 1; i >= 0; i--)
741	<	siftDown(i, (E) queue[i]);
740	>	final Object[] es = queue;
741	>	int n = size, i = (n >>> 1) - 1;
742	>	final Comparator<? super E> cmp;
743	>	if ((cmp = comparator) == null)
744	>	for (; i >= 0; i--)
745	>	siftDownComparable(i, (E) es[i], es, n);
746	>	else
747	>	for (; i >= 0; i--)
748	>	siftDownUsingComparator(i, (E) es[i], es, n, cmp);
749		}
750
751		/**
#	Line 672 | Line 762 | public class PriorityQueue<E> extends Ab
762		}
763
764		/**
765	<	* Saves the state of the instance to a stream (that
676	<	* is, serializes it).
765	>	* Saves this queue to a stream (that is, serializes it).
766		*
767	+	* @param s the stream
768	+	* @throws java.io.IOException if an I/O error occurs
769		* @serialData The length of the array backing the instance is
770		*             emitted (int), followed by all of its elements
771		*             (each an {@code Object}) in the proper order.
681	–	* @param s the stream
772		*/
773		private void writeObject(java.io.ObjectOutputStream s)
774	<	throws java.io.IOException{
774	>	throws java.io.IOException {
775		// Write out element count, and any hidden stuff
776		s.defaultWriteObject();
777
778		// Write out array length, for compatibility with 1.5 version
779		s.writeInt(Math.max(2, size + 1));
780
781	<	// Write out all elements in the proper order.
782	<	for (int i = 0; i < size; i++)
783	<	s.writeObject(queue[i]);
781	>	// Write out all elements in the "proper order".
782	>	final Object[] es = queue;
783	>	for (int i = 0, n = size; i < n; i++)
784	>	s.writeObject(es[i]);
785		}
786
787		/**
#	Line 698 | Line 789 | public class PriorityQueue<E> extends Ab
789		* (that is, deserializes it).
790		*
791		* @param s the stream
792	+	* @throws ClassNotFoundException if the class of a serialized object
793	+	*         could not be found
794	+	* @throws java.io.IOException if an I/O error occurs
795		*/
796		private void readObject(java.io.ObjectInputStream s)
797		throws java.io.IOException, ClassNotFoundException {
#	Line 707 | Line 801 | public class PriorityQueue<E> extends Ab
801		// Read in (and discard) array length
802		s.readInt();
803
804	<	queue = new Object[size];
804	>	SharedSecrets.getJavaObjectInputStreamAccess().checkArray(s, Object[].class, size);
805	>	final Object[] es = queue = new Object[Math.max(size, 1)];
806	>
807	>	// Read in all elements.
808	>	for (int i = 0, n = size; i < n; i++)
809	>	es[i] = s.readObject();
810	>
811	>	// Elements are guaranteed to be in "proper order", but the
812	>	// spec has never explained what that might be.
813	>	heapify();
814	>	}
815	>
816	>	/**
817	>	* Creates a <em><a href="Spliterator.html#binding">late-binding</a></em>
818	>	* and <em>fail-fast</em> {@link Spliterator} over the elements in this
819	>	* queue. The spliterator does not traverse elements in any particular order
820	>	* (the {@link Spliterator#ORDERED ORDERED} characteristic is not reported).
821	>	*
822	>	* <p>The {@code Spliterator} reports {@link Spliterator#SIZED},
823	>	* {@link Spliterator#SUBSIZED}, and {@link Spliterator#NONNULL}.
824	>	* Overriding implementations should document the reporting of additional
825	>	* characteristic values.
826	>	*
827	>	* @return a {@code Spliterator} over the elements in this queue
828	>	* @since 1.8
829	>	*/
830	>	public final Spliterator<E> spliterator() {
831	>	return new PriorityQueueSpliterator(0, -1, 0);
832	>	}
833	>
834	>	final class PriorityQueueSpliterator implements Spliterator<E> {
835	>	private int index;            // current index, modified on advance/split
836	>	private int fence;            // -1 until first use
837	>	private int expectedModCount; // initialized when fence set
838	>
839	>	/** Creates new spliterator covering the given range. */
840	>	PriorityQueueSpliterator(int origin, int fence, int expectedModCount) {
841	>	this.index = origin;
842	>	this.fence = fence;
843	>	this.expectedModCount = expectedModCount;
844	>	}
845	>
846	>	private int getFence() { // initialize fence to size on first use
847	>	int hi;
848	>	if ((hi = fence) < 0) {
849	>	expectedModCount = modCount;
850	>	hi = fence = size;
851	>	}
852	>	return hi;
853	>	}
854	>
855	>	public PriorityQueueSpliterator trySplit() {
856	>	int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
857	>	return (lo >= mid) ? null :
858	>	new PriorityQueueSpliterator(lo, index = mid, expectedModCount);
859	>	}
860	>
861	>	public void forEachRemaining(Consumer<? super E> action) {
862	>	if (action == null)
863	>	throw new NullPointerException();
864	>	if (fence < 0) { fence = size; expectedModCount = modCount; }
865	>	final Object[] es = queue;
866	>	int i, hi; E e;
867	>	for (i = index, index = hi = fence; i < hi; i++) {
868	>	if ((e = (E) es[i]) == null)
869	>	break;      // must be CME
870	>	action.accept(e);
871	>	}
872	>	if (modCount != expectedModCount)
873	>	throw new ConcurrentModificationException();
874	>	}
875
876	<	// Read in all elements in the proper order.
877	<	for (int i = 0; i < size; i++)
878	<	queue[i] = s.readObject();
876	>	public boolean tryAdvance(Consumer<? super E> action) {
877	>	if (action == null)
878	>	throw new NullPointerException();
879	>	if (fence < 0) { fence = size; expectedModCount = modCount; }
880	>	int i;
881	>	if ((i = index) < fence) {
882	>	index = i + 1;
883	>	E e;
884	>	if ((e = (E) queue[i]) == null
885	>	|| modCount != expectedModCount)
886	>	throw new ConcurrentModificationException();
887	>	action.accept(e);
888	>	return true;
889	>	}
890	>	return false;
891	>	}
892	>
893	>	public long estimateSize() {
894	>	return getFence() - index;
895	>	}
896	>
897	>	public int characteristics() {
898	>	return Spliterator.SIZED | Spliterator.SUBSIZED | Spliterator.NONNULL;
899	>	}
900	>	}
901	>
902	>	/**
903	>	* @throws NullPointerException {@inheritDoc}
904	>	*/
905	>	public void forEach(Consumer<? super E> action) {
906	>	Objects.requireNonNull(action);
907	>	final int expectedModCount = modCount;
908	>	final Object[] es = queue;
909	>	for (int i = 0, n = size; i < n; i++)
910	>	action.accept((E) es[i]);
911	>	if (expectedModCount != modCount)
912	>	throw new ConcurrentModificationException();
913		}
914		}

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