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Comparing jsr166/src/main/java/util/ArrayList.java (file contents):
Revision 1.27 by jsr166, Sun May 18 23:59:57 2008 UTC vs.
Revision 1.69 by jsr166, Fri Aug 30 18:05:39 2019 UTC

#	Line 1 | Line 1
1		/*
2	<	* Copyright 1997-2007 Sun Microsystems, Inc.  All Rights Reserved.
2	>	* Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
3		* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4		*
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.  Sun designates this
7	>	* published by the Free Software Foundation.  Oracle designates this
8		* particular file as subject to the "Classpath" exception as provided
9	<	* by Sun in the LICENSE file that accompanied this code.
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
#	Line 18 | Line 18
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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22	<	* CA 95054 USA or visit www.sun.com if you need additional information or
23	<	* have any questions.
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 java.util.function.Predicate;
30	+	import java.util.function.UnaryOperator;
31	+	// OPENJDK import jdk.internal.access.SharedSecrets;
32	+	import jdk.internal.util.ArraysSupport;
33	+
34		/**
35	<	* Resizable-array implementation of the <tt>List</tt> interface.  Implements
35	>	* Resizable-array implementation of the {@code List} interface.  Implements
36		* all optional list operations, and permits all elements, including
37	<	* <tt>null</tt>.  In addition to implementing the <tt>List</tt> interface,
37	>	* {@code null}.  In addition to implementing the {@code List} interface,
38		* this class provides methods to manipulate the size of the array that is
39		* used internally to store the list.  (This class is roughly equivalent to
40	<	* <tt>Vector</tt>, except that it is unsynchronized.)
40	>	* {@code Vector}, except that it is unsynchronized.)
41		*
42	<	* <p>The <tt>size</tt>, <tt>isEmpty</tt>, <tt>get</tt>, <tt>set</tt>,
43	<	* <tt>iterator</tt>, and <tt>listIterator</tt> operations run in constant
44	<	* time.  The <tt>add</tt> operation runs in <i>amortized constant time</i>,
42	>	* <p>The {@code size}, {@code isEmpty}, {@code get}, {@code set},
43	>	* {@code iterator}, and {@code listIterator} operations run in constant
44	>	* time.  The {@code add} operation runs in <i>amortized constant time</i>,
45		* that is, adding n elements requires O(n) time.  All of the other operations
46		* run in linear time (roughly speaking).  The constant factor is low compared
47	<	* to that for the <tt>LinkedList</tt> implementation.
47	>	* to that for the {@code LinkedList} implementation.
48		*
49	<	* <p>Each <tt>ArrayList</tt> instance has a <i>capacity</i>.  The capacity is
49	>	* <p>Each {@code ArrayList} instance has a <i>capacity</i>.  The capacity is
50		* the size of the array used to store the elements in the list.  It is always
51		* at least as large as the list size.  As elements are added to an ArrayList,
52		* its capacity grows automatically.  The details of the growth policy are not
53		* specified beyond the fact that adding an element has constant amortized
54		* time cost.
55		*
56	<	* <p>An application can increase the capacity of an <tt>ArrayList</tt> instance
57	<	* before adding a large number of elements using the <tt>ensureCapacity</tt>
56	>	* <p>An application can increase the capacity of an {@code ArrayList} instance
57	>	* before adding a large number of elements using the {@code ensureCapacity}
58		* operation.  This may reduce the amount of incremental reallocation.
59		*
60		* <p><strong>Note that this implementation is not synchronized.</strong>
61	<	* If multiple threads access an <tt>ArrayList</tt> instance concurrently,
61	>	* If multiple threads access an {@code ArrayList} instance concurrently,
62		* and at least one of the threads modifies the list structurally, it
63		* <i>must</i> be synchronized externally.  (A structural modification is
64		* any operation that adds or deletes one or more elements, or explicitly
#	Line 66 | Line 72 | package java.util;
72		* unsynchronized access to the list:<pre>
73		*   List list = Collections.synchronizedList(new ArrayList(...));</pre>
74		*
75	<	* <p><a name="fail-fast"/>
75	>	* <p id="fail-fast">
76		* The iterators returned by this class's {@link #iterator() iterator} and
77		* {@link #listIterator(int) listIterator} methods are <em>fail-fast</em>:
78		* if the list is structurally modified at any time after the iterator is
#	Line 87 | Line 93 | package java.util;
93		* should be used only to detect bugs.</i>
94		*
95		* <p>This class is a member of the
96	<	* <a href="{@docRoot}/../technotes/guides/collections/index.html">
96	>	* <a href="{@docRoot}/java.base/java/util/package-summary.html#CollectionsFramework">
97		* Java Collections Framework</a>.
98		*
99	+	* @param <E> the type of elements in this list
100	+	*
101		* @author  Josh Bloch
102		* @author  Neal Gafter
103		* @see     Collection
#	Line 98 | Line 106 | package java.util;
106		* @see     Vector
107		* @since   1.2
108		*/
101	–
109		public class ArrayList<E> extends AbstractList<E>
110		implements List<E>, RandomAccess, Cloneable, java.io.Serializable
111		{
112	+	// OPENJDK @java.io.Serial
113		private static final long serialVersionUID = 8683452581122892189L;
114
115		/**
116	+	* Default initial capacity.
117	+	*/
118	+	private static final int DEFAULT_CAPACITY = 10;
119	+
120	+	/**
121	+	* Shared empty array instance used for empty instances.
122	+	*/
123	+	private static final Object[] EMPTY_ELEMENTDATA = {};
124	+
125	+	/**
126	+	* Shared empty array instance used for default sized empty instances. We
127	+	* distinguish this from EMPTY_ELEMENTDATA to know how much to inflate when
128	+	* first element is added.
129	+	*/
130	+	private static final Object[] DEFAULTCAPACITY_EMPTY_ELEMENTDATA = {};
131	+
132	+	/**
133		* The array buffer into which the elements of the ArrayList are stored.
134	<	* The capacity of the ArrayList is the length of this array buffer.
134	>	* The capacity of the ArrayList is the length of this array buffer. Any
135	>	* empty ArrayList with elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA
136	>	* will be expanded to DEFAULT_CAPACITY when the first element is added.
137		*/
138	<	private transient Object[] elementData;
138	>	transient Object[] elementData; // non-private to simplify nested class access
139
140		/**
141		* The size of the ArrayList (the number of elements it contains).
#	Line 120 | Line 147 | public class ArrayList<E> extends Abstra
147		/**
148		* Constructs an empty list with the specified initial capacity.
149		*
150	<	* @param   initialCapacity   the initial capacity of the list
151	<	* @exception IllegalArgumentException if the specified initial capacity
152	<	*            is negative
150	>	* @param  initialCapacity  the initial capacity of the list
151	>	* @throws IllegalArgumentException if the specified initial capacity
152	>	*         is negative
153		*/
154		public ArrayList(int initialCapacity) {
155	<	super();
156	<	if (initialCapacity < 0)
155	>	if (initialCapacity > 0) {
156	>	this.elementData = new Object[initialCapacity];
157	>	} else if (initialCapacity == 0) {
158	>	this.elementData = EMPTY_ELEMENTDATA;
159	>	} else {
160		throw new IllegalArgumentException("Illegal Capacity: "+
161		initialCapacity);
162	<	this.elementData = new Object[initialCapacity];
162	>	}
163		}
164
165		/**
166		* Constructs an empty list with an initial capacity of ten.
167		*/
168		public ArrayList() {
169	<	this(10);
169	>	this.elementData = DEFAULTCAPACITY_EMPTY_ELEMENTDATA;
170		}
171
172		/**
#	Line 149 | Line 179 | public class ArrayList<E> extends Abstra
179		*/
180		public ArrayList(Collection<? extends E> c) {
181		elementData = c.toArray();
182	<	size = elementData.length;
183	<	// c.toArray might (incorrectly) not return Object[] (see 6260652)
184	<	if (elementData.getClass() != Object[].class)
185	<	elementData = Arrays.copyOf(elementData, size, Object[].class);
182	>	if ((size = elementData.length) != 0) {
183	>	// defend against c.toArray (incorrectly) not returning Object[]
184	>	// (see e.g. https://bugs.openjdk.java.net/browse/JDK-6260652)
185	>	if (elementData.getClass() != Object[].class)
186	>	elementData = Arrays.copyOf(elementData, size, Object[].class);
187	>	} else {
188	>	// replace with empty array.
189	>	this.elementData = EMPTY_ELEMENTDATA;
190	>	}
191		}
192
193		/**
194	<	* Trims the capacity of this <tt>ArrayList</tt> instance to be the
194	>	* Trims the capacity of this {@code ArrayList} instance to be the
195		* list's current size.  An application can use this operation to minimize
196	<	* the storage of an <tt>ArrayList</tt> instance.
196	>	* the storage of an {@code ArrayList} instance.
197		*/
198		public void trimToSize() {
199		modCount++;
200	<	int oldCapacity = elementData.length;
201	<	if (size < oldCapacity) {
202	<	elementData = Arrays.copyOf(elementData, size);
200	>	if (size < elementData.length) {
201	>	elementData = (size == 0)
202	>	? EMPTY_ELEMENTDATA
203	>	: Arrays.copyOf(elementData, size);
204		}
205		}
206
207		/**
208	<	* Increases the capacity of this <tt>ArrayList</tt> instance, if
208	>	* Increases the capacity of this {@code ArrayList} instance, if
209		* necessary, to ensure that it can hold at least the number of elements
210		* specified by the minimum capacity argument.
211		*
212	<	* @param   minCapacity   the desired minimum capacity
212	>	* @param minCapacity the desired minimum capacity
213		*/
214		public void ensureCapacity(int minCapacity) {
215	<	modCount++;
215	>	if (minCapacity > elementData.length
216	>	&& !(elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA
217	>	&& minCapacity <= DEFAULT_CAPACITY)) {
218	>	modCount++;
219	>	grow(minCapacity);
220	>	}
221	>	}
222	>
223	>	/**
224	>	* Increases the capacity to ensure that it can hold at least the
225	>	* number of elements specified by the minimum capacity argument.
226	>	*
227	>	* @param minCapacity the desired minimum capacity
228	>	* @throws OutOfMemoryError if minCapacity is less than zero
229	>	*/
230	>	private Object[] grow(int minCapacity) {
231		int oldCapacity = elementData.length;
232	<	if (minCapacity > oldCapacity) {
233	<	Object oldData[] = elementData;
234	<	int newCapacity = (oldCapacity * 3)/2 + 1;
235	<	if (newCapacity < minCapacity)
236	<	newCapacity = minCapacity;
237	<	// minCapacity is usually close to size, so this is a win:
238	<	elementData = Arrays.copyOf(elementData, newCapacity);
232	>	if (oldCapacity > 0 || elementData != DEFAULTCAPACITY_EMPTY_ELEMENTDATA) {
233	>	int newCapacity = ArraysSupport.newLength(oldCapacity,
234	>	minCapacity - oldCapacity, /* minimum growth */
235	>	oldCapacity >> 1           /* preferred growth */);
236	>	return elementData = Arrays.copyOf(elementData, newCapacity);
237	>	} else {
238	>	return elementData = new Object[Math.max(DEFAULT_CAPACITY, minCapacity)];
239		}
240		}
241
242	+	private Object[] grow() {
243	+	return grow(size + 1);
244	+	}
245	+
246		/**
247		* Returns the number of elements in this list.
248		*
#	Line 198 | Line 253 | public class ArrayList<E> extends Abstra
253		}
254
255		/**
256	<	* Returns <tt>true</tt> if this list contains no elements.
256	>	* Returns {@code true} if this list contains no elements.
257		*
258	<	* @return <tt>true</tt> if this list contains no elements
258	>	* @return {@code true} if this list contains no elements
259		*/
260		public boolean isEmpty() {
261		return size == 0;
262		}
263
264		/**
265	<	* Returns <tt>true</tt> if this list contains the specified element.
266	<	* More formally, returns <tt>true</tt> if and only if this list contains
267	<	* at least one element <tt>e</tt> such that
268	<	* <tt>(o==null&nbsp;?&nbsp;e==null&nbsp;:&nbsp;o.equals(e))</tt>.
265	>	* Returns {@code true} if this list contains the specified element.
266	>	* More formally, returns {@code true} if and only if this list contains
267	>	* at least one element {@code e} such that
268	>	* {@code Objects.equals(o, e)}.
269		*
270		* @param o element whose presence in this list is to be tested
271	<	* @return <tt>true</tt> if this list contains the specified element
271	>	* @return {@code true} if this list contains the specified element
272		*/
273		public boolean contains(Object o) {
274		return indexOf(o) >= 0;
#	Line 222 | Line 277 | public class ArrayList<E> extends Abstra
277		/**
278		* Returns the index of the first occurrence of the specified element
279		* in this list, or -1 if this list does not contain the element.
280	<	* More formally, returns the lowest index <tt>i</tt> such that
281	<	* <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
280	>	* More formally, returns the lowest index {@code i} such that
281	>	* {@code Objects.equals(o, get(i))},
282		* or -1 if there is no such index.
283		*/
284		public int indexOf(Object o) {
285	+	return indexOfRange(o, 0, size);
286	+	}
287	+
288	+	int indexOfRange(Object o, int start, int end) {
289	+	Object[] es = elementData;
290		if (o == null) {
291	<	for (int i = 0; i < size; i++)
292	<	if (elementData[i]==null)
291	>	for (int i = start; i < end; i++) {
292	>	if (es[i] == null) {
293		return i;
294	+	}
295	+	}
296		} else {
297	<	for (int i = 0; i < size; i++)
298	<	if (o.equals(elementData[i]))
297	>	for (int i = start; i < end; i++) {
298	>	if (o.equals(es[i])) {
299		return i;
300	+	}
301	+	}
302		}
303		return -1;
304		}
#	Line 242 | Line 306 | public class ArrayList<E> extends Abstra
306		/**
307		* Returns the index of the last occurrence of the specified element
308		* in this list, or -1 if this list does not contain the element.
309	<	* More formally, returns the highest index <tt>i</tt> such that
310	<	* <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
309	>	* More formally, returns the highest index {@code i} such that
310	>	* {@code Objects.equals(o, get(i))},
311		* or -1 if there is no such index.
312		*/
313		public int lastIndexOf(Object o) {
314	+	return lastIndexOfRange(o, 0, size);
315	+	}
316	+
317	+	int lastIndexOfRange(Object o, int start, int end) {
318	+	Object[] es = elementData;
319		if (o == null) {
320	<	for (int i = size-1; i >= 0; i--)
321	<	if (elementData[i]==null)
320	>	for (int i = end - 1; i >= start; i--) {
321	>	if (es[i] == null) {
322		return i;
323	+	}
324	+	}
325		} else {
326	<	for (int i = size-1; i >= 0; i--)
327	<	if (o.equals(elementData[i]))
326	>	for (int i = end - 1; i >= start; i--) {
327	>	if (o.equals(es[i])) {
328		return i;
329	+	}
330	+	}
331		}
332		return -1;
333		}
334
335		/**
336	<	* Returns a shallow copy of this <tt>ArrayList</tt> instance.  (The
336	>	* Returns a shallow copy of this {@code ArrayList} instance.  (The
337		* elements themselves are not copied.)
338		*
339	<	* @return a clone of this <tt>ArrayList</tt> instance
339	>	* @return a clone of this {@code ArrayList} instance
340		*/
341		public Object clone() {
342		try {
343	<	@SuppressWarnings("unchecked")
271	<	ArrayList<E> v = (ArrayList<E>) super.clone();
343	>	ArrayList<?> v = (ArrayList<?>) super.clone();
344		v.elementData = Arrays.copyOf(elementData, size);
345		v.modCount = 0;
346		return v;
347		} catch (CloneNotSupportedException e) {
348		// this shouldn't happen, since we are Cloneable
349	<	throw new InternalError();
349	>	throw new InternalError(e);
350		}
351		}
352
#	Line 307 | Line 379 | public class ArrayList<E> extends Abstra
379		* <p>If the list fits in the specified array with room to spare
380		* (i.e., the array has more elements than the list), the element in
381		* the array immediately following the end of the collection is set to
382	<	* <tt>null</tt>.  (This is useful in determining the length of the
382	>	* {@code null}.  (This is useful in determining the length of the
383		* list <i>only</i> if the caller knows that the list does not contain
384		* any null elements.)
385		*
#	Line 338 | Line 410 | public class ArrayList<E> extends Abstra
410		return (E) elementData[index];
411		}
412
413	+	@SuppressWarnings("unchecked")
414	+	static <E> E elementAt(Object[] es, int index) {
415	+	return (E) es[index];
416	+	}
417	+
418		/**
419		* Returns the element at the specified position in this list.
420		*
#	Line 346 | Line 423 | public class ArrayList<E> extends Abstra
423		* @throws IndexOutOfBoundsException {@inheritDoc}
424		*/
425		public E get(int index) {
426	<	rangeCheck(index);
350	<
426	>	Objects.checkIndex(index, size);
427		return elementData(index);
428		}
429
#	Line 361 | Line 437 | public class ArrayList<E> extends Abstra
437		* @throws IndexOutOfBoundsException {@inheritDoc}
438		*/
439		public E set(int index, E element) {
440	<	rangeCheck(index);
365	<
440	>	Objects.checkIndex(index, size);
441		E oldValue = elementData(index);
442		elementData[index] = element;
443		return oldValue;
444		}
445
446		/**
447	+	* This helper method split out from add(E) to keep method
448	+	* bytecode size under 35 (the -XX:MaxInlineSize default value),
449	+	* which helps when add(E) is called in a C1-compiled loop.
450	+	*/
451	+	private void add(E e, Object[] elementData, int s) {
452	+	if (s == elementData.length)
453	+	elementData = grow();
454	+	elementData[s] = e;
455	+	size = s + 1;
456	+	}
457	+
458	+	/**
459		* Appends the specified element to the end of this list.
460		*
461		* @param e element to be appended to this list
462	<	* @return <tt>true</tt> (as specified by {@link Collection#add})
462	>	* @return {@code true} (as specified by {@link Collection#add})
463		*/
464		public boolean add(E e) {
465	<	ensureCapacity(size + 1);  // Increments modCount!!
466	<	elementData[size++] = e;
465	>	modCount++;
466	>	add(e, elementData, size);
467		return true;
468		}
469
#	Line 391 | Line 478 | public class ArrayList<E> extends Abstra
478		*/
479		public void add(int index, E element) {
480		rangeCheckForAdd(index);
481	<
482	<	ensureCapacity(size+1);  // Increments modCount!!
483	<	System.arraycopy(elementData, index, elementData, index + 1,
484	<	size - index);
481	>	modCount++;
482	>	final int s;
483	>	Object[] elementData;
484	>	if ((s = size) == (elementData = this.elementData).length)
485	>	elementData = grow();
486	>	System.arraycopy(elementData, index,
487	>	elementData, index + 1,
488	>	s - index);
489		elementData[index] = element;
490	<	size++;
490	>	size = s + 1;
491	>	// checkInvariants();
492		}
493
494		/**
#	Line 409 | Line 501 | public class ArrayList<E> extends Abstra
501		* @throws IndexOutOfBoundsException {@inheritDoc}
502		*/
503		public E remove(int index) {
504	<	rangeCheck(index);
505	<
414	<	modCount++;
415	<	E oldValue = elementData(index);
504	>	Objects.checkIndex(index, size);
505	>	final Object[] es = elementData;
506
507	<	int numMoved = size - index - 1;
508	<	if (numMoved > 0)
419	<	System.arraycopy(elementData, index+1, elementData, index,
420	<	numMoved);
421	<	elementData[--size] = null; // Let gc do its work
507	>	@SuppressWarnings("unchecked") E oldValue = (E) es[index];
508	>	fastRemove(es, index);
509
510	+	// checkInvariants();
511		return oldValue;
512		}
513
514		/**
515	+	* {@inheritDoc}
516	+	*/
517	+	public boolean equals(Object o) {
518	+	if (o == this) {
519	+	return true;
520	+	}
521	+
522	+	if (!(o instanceof List)) {
523	+	return false;
524	+	}
525	+
526	+	final int expectedModCount = modCount;
527	+	// ArrayList can be subclassed and given arbitrary behavior, but we can
528	+	// still deal with the common case where o is ArrayList precisely
529	+	boolean equal = (o.getClass() == ArrayList.class)
530	+	? equalsArrayList((ArrayList<?>) o)
531	+	: equalsRange((List<?>) o, 0, size);
532	+
533	+	checkForComodification(expectedModCount);
534	+	return equal;
535	+	}
536	+
537	+	boolean equalsRange(List<?> other, int from, int to) {
538	+	final Object[] es = elementData;
539	+	if (to > es.length) {
540	+	throw new ConcurrentModificationException();
541	+	}
542	+	var oit = other.iterator();
543	+	for (; from < to; from++) {
544	+	if (!oit.hasNext() || !Objects.equals(es[from], oit.next())) {
545	+	return false;
546	+	}
547	+	}
548	+	return !oit.hasNext();
549	+	}
550	+
551	+	private boolean equalsArrayList(ArrayList<?> other) {
552	+	final int otherModCount = other.modCount;
553	+	final int s = size;
554	+	boolean equal;
555	+	if (equal = (s == other.size)) {
556	+	final Object[] otherEs = other.elementData;
557	+	final Object[] es = elementData;
558	+	if (s > es.length || s > otherEs.length) {
559	+	throw new ConcurrentModificationException();
560	+	}
561	+	for (int i = 0; i < s; i++) {
562	+	if (!Objects.equals(es[i], otherEs[i])) {
563	+	equal = false;
564	+	break;
565	+	}
566	+	}
567	+	}
568	+	other.checkForComodification(otherModCount);
569	+	return equal;
570	+	}
571	+
572	+	private void checkForComodification(final int expectedModCount) {
573	+	if (modCount != expectedModCount) {
574	+	throw new ConcurrentModificationException();
575	+	}
576	+	}
577	+
578	+	/**
579	+	* {@inheritDoc}
580	+	*/
581	+	public int hashCode() {
582	+	int expectedModCount = modCount;
583	+	int hash = hashCodeRange(0, size);
584	+	checkForComodification(expectedModCount);
585	+	return hash;
586	+	}
587	+
588	+	int hashCodeRange(int from, int to) {
589	+	final Object[] es = elementData;
590	+	if (to > es.length) {
591	+	throw new ConcurrentModificationException();
592	+	}
593	+	int hashCode = 1;
594	+	for (int i = from; i < to; i++) {
595	+	Object e = es[i];
596	+	hashCode = 31 * hashCode + (e == null ? 0 : e.hashCode());
597	+	}
598	+	return hashCode;
599	+	}
600	+
601	+	/**
602		* Removes the first occurrence of the specified element from this list,
603		* if it is present.  If the list does not contain the element, it is
604		* unchanged.  More formally, removes the element with the lowest index
605	<	* <tt>i</tt> such that
606	<	* <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>
607	<	* (if such an element exists).  Returns <tt>true</tt> if this list
605	>	* {@code i} such that
606	>	* {@code Objects.equals(o, get(i))}
607	>	* (if such an element exists).  Returns {@code true} if this list
608		* contained the specified element (or equivalently, if this list
609		* changed as a result of the call).
610		*
611		* @param o element to be removed from this list, if present
612	<	* @return <tt>true</tt> if this list contained the specified element
612	>	* @return {@code true} if this list contained the specified element
613		*/
614		public boolean remove(Object o) {
615	<	if (o == null) {
616	<	for (int index = 0; index < size; index++)
617	<	if (elementData[index] == null) {
618	<	fastRemove(index);
619	<	return true;
620	<	}
621	<	} else {
622	<	for (int index = 0; index < size; index++)
623	<	if (o.equals(elementData[index])) {
624	<	fastRemove(index);
625	<	return true;
626	<	}
615	>	final Object[] es = elementData;
616	>	final int size = this.size;
617	>	int i = 0;
618	>	found: {
619	>	if (o == null) {
620	>	for (; i < size; i++)
621	>	if (es[i] == null)
622	>	break found;
623	>	} else {
624	>	for (; i < size; i++)
625	>	if (o.equals(es[i]))
626	>	break found;
627	>	}
628	>	return false;
629		}
630	<	return false;
630	>	fastRemove(es, i);
631	>	return true;
632		}
633
634	<	/*
634	>	/**
635		* Private remove method that skips bounds checking and does not
636		* return the value removed.
637		*/
638	<	private void fastRemove(int index) {
638	>	private void fastRemove(Object[] es, int i) {
639		modCount++;
640	<	int numMoved = size - index - 1;
641	<	if (numMoved > 0)
642	<	System.arraycopy(elementData, index+1, elementData, index,
643	<	numMoved);
466	<	elementData[--size] = null; // Let gc do its work
640	>	final int newSize;
641	>	if ((newSize = size - 1) > i)
642	>	System.arraycopy(es, i + 1, es, i, newSize - i);
643	>	es[size = newSize] = null;
644		}
645
646		/**
#	Line 472 | Line 649 | public class ArrayList<E> extends Abstra
649		*/
650		public void clear() {
651		modCount++;
652	<
653	<	// Let gc do its work
654	<	for (int i = 0; i < size; i++)
478	<	elementData[i] = null;
479	<
480	<	size = 0;
652	>	final Object[] es = elementData;
653	>	for (int to = size, i = size = 0; i < to; i++)
654	>	es[i] = null;
655		}
656
657		/**
#	Line 490 | Line 664 | public class ArrayList<E> extends Abstra
664		* list is nonempty.)
665		*
666		* @param c collection containing elements to be added to this list
667	<	* @return <tt>true</tt> if this list changed as a result of the call
667	>	* @return {@code true} if this list changed as a result of the call
668		* @throws NullPointerException if the specified collection is null
669		*/
670		public boolean addAll(Collection<? extends E> c) {
671		Object[] a = c.toArray();
672	+	modCount++;
673		int numNew = a.length;
674	<	ensureCapacity(size + numNew);  // Increments modCount
675	<	System.arraycopy(a, 0, elementData, size, numNew);
676	<	size += numNew;
677	<	return numNew != 0;
674	>	if (numNew == 0)
675	>	return false;
676	>	Object[] elementData;
677	>	final int s;
678	>	if (numNew > (elementData = this.elementData).length - (s = size))
679	>	elementData = grow(s + numNew);
680	>	System.arraycopy(a, 0, elementData, s, numNew);
681	>	size = s + numNew;
682	>	// checkInvariants();
683	>	return true;
684		}
685
686		/**
#	Line 513 | Line 694 | public class ArrayList<E> extends Abstra
694		* @param index index at which to insert the first element from the
695		*              specified collection
696		* @param c collection containing elements to be added to this list
697	<	* @return <tt>true</tt> if this list changed as a result of the call
697	>	* @return {@code true} if this list changed as a result of the call
698		* @throws IndexOutOfBoundsException {@inheritDoc}
699		* @throws NullPointerException if the specified collection is null
700		*/
#	Line 521 | Line 702 | public class ArrayList<E> extends Abstra
702		rangeCheckForAdd(index);
703
704		Object[] a = c.toArray();
705	+	modCount++;
706		int numNew = a.length;
707	<	ensureCapacity(size + numNew);  // Increments modCount
707	>	if (numNew == 0)
708	>	return false;
709	>	Object[] elementData;
710	>	final int s;
711	>	if (numNew > (elementData = this.elementData).length - (s = size))
712	>	elementData = grow(s + numNew);
713
714	<	int numMoved = size - index;
714	>	int numMoved = s - index;
715		if (numMoved > 0)
716	<	System.arraycopy(elementData, index, elementData, index + numNew,
716	>	System.arraycopy(elementData, index,
717	>	elementData, index + numNew,
718		numMoved);
531	–
719		System.arraycopy(a, 0, elementData, index, numNew);
720	<	size += numNew;
721	<	return numNew != 0;
720	>	size = s + numNew;
721	>	// checkInvariants();
722	>	return true;
723		}
724
725		/**
#	Line 544 | Line 732 | public class ArrayList<E> extends Abstra
732		* @throws IndexOutOfBoundsException if {@code fromIndex} or
733		*         {@code toIndex} is out of range
734		*         ({@code fromIndex < 0 ||
547	–	*          fromIndex >= size() ||
735		*          toIndex > size() ||
736		*          toIndex < fromIndex})
737		*/
738		protected void removeRange(int fromIndex, int toIndex) {
739	+	if (fromIndex > toIndex) {
740	+	throw new IndexOutOfBoundsException(
741	+	outOfBoundsMsg(fromIndex, toIndex));
742	+	}
743		modCount++;
744	<	int numMoved = size - toIndex;
745	<	System.arraycopy(elementData, toIndex, elementData, fromIndex,
555	<	numMoved);
556	<
557	<	// Let gc do its work
558	<	int newSize = size - (toIndex-fromIndex);
559	<	while (size != newSize)
560	<	elementData[--size] = null;
744	>	shiftTailOverGap(elementData, fromIndex, toIndex);
745	>	// checkInvariants();
746		}
747
748	<	/**
749	<	* Checks if the given index is in range.  If not, throws an appropriate
750	<	* runtime exception.  This method does *not* check if the index is
751	<	* negative: It is always used immediately prior to an array access,
752	<	* which throws an ArrayIndexOutOfBoundsException if index is negative.
568	<	*/
569	<	private void rangeCheck(int index) {
570	<	if (index >= size)
571	<	throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
748	>	/** Erases the gap from lo to hi, by sliding down following elements. */
749	>	private void shiftTailOverGap(Object[] es, int lo, int hi) {
750	>	System.arraycopy(es, hi, es, lo, size - hi);
751	>	for (int to = size, i = (size -= hi - lo); i < to; i++)
752	>	es[i] = null;
753		}
754
755		/**
#	Line 589 | Line 770 | public class ArrayList<E> extends Abstra
770		}
771
772		/**
773	+	* A version used in checking (fromIndex > toIndex) condition
774	+	*/
775	+	private static String outOfBoundsMsg(int fromIndex, int toIndex) {
776	+	return "From Index: " + fromIndex + " > To Index: " + toIndex;
777	+	}
778	+
779	+	/**
780		* Removes from this list all of its elements that are contained in the
781		* specified collection.
782		*
783		* @param c collection containing elements to be removed from this list
784		* @return {@code true} if this list changed as a result of the call
785		* @throws ClassCastException if the class of an element of this list
786	<	*         is incompatible with the specified collection (optional)
786	>	*         is incompatible with the specified collection
787	>	* (<a href="Collection.html#optional-restrictions">optional</a>)
788		* @throws NullPointerException if this list contains a null element and the
789	<	*         specified collection does not permit null elements (optional),
789	>	*         specified collection does not permit null elements
790	>	* (<a href="Collection.html#optional-restrictions">optional</a>),
791		*         or if the specified collection is null
792		* @see Collection#contains(Object)
793		*/
794		public boolean removeAll(Collection<?> c) {
795	<	return batchRemove(c, false);
795	>	return batchRemove(c, false, 0, size);
796		}
797
798		/**
#	Line 613 | Line 803 | public class ArrayList<E> extends Abstra
803		* @param c collection containing elements to be retained in this list
804		* @return {@code true} if this list changed as a result of the call
805		* @throws ClassCastException if the class of an element of this list
806	<	*         is incompatible with the specified collection (optional)
806	>	*         is incompatible with the specified collection
807	>	* (<a href="Collection.html#optional-restrictions">optional</a>)
808		* @throws NullPointerException if this list contains a null element and the
809	<	*         specified collection does not permit null elements (optional),
809	>	*         specified collection does not permit null elements
810	>	* (<a href="Collection.html#optional-restrictions">optional</a>),
811		*         or if the specified collection is null
812		* @see Collection#contains(Object)
813		*/
814		public boolean retainAll(Collection<?> c) {
815	<	return batchRemove(c, true);
815	>	return batchRemove(c, true, 0, size);
816		}
817
818	<	private boolean batchRemove(Collection<?> c, boolean complement) {
819	<	final Object[] elementData = this.elementData;
820	<	int r = 0, w = 0;
821	<	boolean modified = false;
818	>	boolean batchRemove(Collection<?> c, boolean complement,
819	>	final int from, final int end) {
820	>	Objects.requireNonNull(c);
821	>	final Object[] es = elementData;
822	>	int r;
823	>	// Optimize for initial run of survivors
824	>	for (r = from;; r++) {
825	>	if (r == end)
826	>	return false;
827	>	if (c.contains(es[r]) != complement)
828	>	break;
829	>	}
830	>	int w = r++;
831		try {
832	<	for (; r < size; r++)
833	<	if (c.contains(elementData[r]) == complement)
834	<	elementData[w++] = elementData[r];
835	<	} finally {
832	>	for (Object e; r < end; r++)
833	>	if (c.contains(e = es[r]) == complement)
834	>	es[w++] = e;
835	>	} catch (Throwable ex) {
836		// Preserve behavioral compatibility with AbstractCollection,
837		// even if c.contains() throws.
838	<	if (r != size) {
839	<	System.arraycopy(elementData, r,
840	<	elementData, w,
841	<	size - r);
842	<	w += size - r;
843	<	}
643	<	if (w != size) {
644	<	for (int i = w; i < size; i++)
645	<	elementData[i] = null;
646	<	modCount += size - w;
647	<	size = w;
648	<	modified = true;
649	<	}
838	>	System.arraycopy(es, r, es, w, end - r);
839	>	w += end - r;
840	>	throw ex;
841	>	} finally {
842	>	modCount += end - w;
843	>	shiftTailOverGap(es, w, end);
844		}
845	<	return modified;
845	>	// checkInvariants();
846	>	return true;
847		}
848
849		/**
850	<	* Save the state of the <tt>ArrayList</tt> instance to a stream (that
851	<	* is, serialize it).
850	>	* Saves the state of the {@code ArrayList} instance to a stream
851	>	* (that is, serializes it).
852		*
853	<	* @serialData The length of the array backing the <tt>ArrayList</tt>
853	>	* @param s the stream
854	>	* @throws java.io.IOException if an I/O error occurs
855	>	* @serialData The length of the array backing the {@code ArrayList}
856		*             instance is emitted (int), followed by all of its elements
857	<	*             (each an <tt>Object</tt>) in the proper order.
857	>	*             (each an {@code Object}) in the proper order.
858		*/
859	+	// OPENJDK @java.io.Serial
860		private void writeObject(java.io.ObjectOutputStream s)
861	<	throws java.io.IOException{
861	>	throws java.io.IOException {
862		// Write out element count, and any hidden stuff
863		int expectedModCount = modCount;
864		s.defaultWriteObject();
865
866	<	// Write out array length
867	<	s.writeInt(elementData.length);
866	>	// Write out size as capacity for behavioral compatibility with clone()
867	>	s.writeInt(size);
868
869		// Write out all elements in the proper order.
870	<	for (int i=0; i<size; i++)
870	>	for (int i=0; i<size; i++) {
871		s.writeObject(elementData[i]);
872	+	}
873
874		if (modCount != expectedModCount) {
875		throw new ConcurrentModificationException();
876		}
678	–
877		}
878
879		/**
880	<	* Reconstitute the <tt>ArrayList</tt> instance from a stream (that is,
881	<	* deserialize it).
880	>	* Reconstitutes the {@code ArrayList} instance from a stream (that is,
881	>	* deserializes it).
882	>	* @param s the stream
883	>	* @throws ClassNotFoundException if the class of a serialized object
884	>	*         could not be found
885	>	* @throws java.io.IOException if an I/O error occurs
886		*/
887	+	// OPENJDK @java.io.Serial
888		private void readObject(java.io.ObjectInputStream s)
889		throws java.io.IOException, ClassNotFoundException {
890	+
891		// Read in size, and any hidden stuff
892		s.defaultReadObject();
893
894	<	// Read in array length and allocate array
895	<	int arrayLength = s.readInt();
896	<	Object[] a = elementData = new Object[arrayLength];
897	<
898	<	// Read in all elements in the proper order.
899	<	for (int i=0; i<size; i++)
900	<	a[i] = s.readObject();
894	>	// Read in capacity
895	>	s.readInt(); // ignored
896	>
897	>	if (size > 0) {
898	>	// like clone(), allocate array based upon size not capacity
899	>	jsr166.Platform.checkArray(s, Object[].class, size);
900	>	Object[] elements = new Object[size];
901	>
902	>	// Read in all elements in the proper order.
903	>	for (int i = 0; i < size; i++) {
904	>	elements[i] = s.readObject();
905	>	}
906	>
907	>	elementData = elements;
908	>	} else if (size == 0) {
909	>	elementData = EMPTY_ELEMENTDATA;
910	>	} else {
911	>	throw new java.io.InvalidObjectException("Invalid size: " + size);
912	>	}
913		}
914
915		/**
#	Line 709 | Line 925 | public class ArrayList<E> extends Abstra
925		* @throws IndexOutOfBoundsException {@inheritDoc}
926		*/
927		public ListIterator<E> listIterator(int index) {
928	<	if (index < 0 || index > size)
713	<	throw new IndexOutOfBoundsException("Index: "+index);
928	>	rangeCheckForAdd(index);
929		return new ListItr(index);
930		}
931
#	Line 745 | Line 960 | public class ArrayList<E> extends Abstra
960		int lastRet = -1; // index of last element returned; -1 if no such
961		int expectedModCount = modCount;
962
963	+	// prevent creating a synthetic constructor
964	+	Itr() {}
965	+
966		public boolean hasNext() {
967		return cursor != size;
968		}
#	Line 777 | Line 995 | public class ArrayList<E> extends Abstra
995		}
996		}
997
998	+	@Override
999	+	public void forEachRemaining(Consumer<? super E> action) {
1000	+	Objects.requireNonNull(action);
1001	+	final int size = ArrayList.this.size;
1002	+	int i = cursor;
1003	+	if (i < size) {
1004	+	final Object[] es = elementData;
1005	+	if (i >= es.length)
1006	+	throw new ConcurrentModificationException();
1007	+	for (; i < size && modCount == expectedModCount; i++)
1008	+	action.accept(elementAt(es, i));
1009	+	// update once at end to reduce heap write traffic
1010	+	cursor = i;
1011	+	lastRet = i - 1;
1012	+	checkForComodification();
1013	+	}
1014	+	}
1015	+
1016		final void checkForComodification() {
1017		if (modCount != expectedModCount)
1018		throw new ConcurrentModificationException();
#	Line 875 | Line 1111 | public class ArrayList<E> extends Abstra
1111		*/
1112		public List<E> subList(int fromIndex, int toIndex) {
1113		subListRangeCheck(fromIndex, toIndex, size);
1114	<	return new SubList(this, 0, fromIndex, toIndex);
1114	>	return new SubList<>(this, fromIndex, toIndex);
1115		}
1116
1117	<	static void subListRangeCheck(int fromIndex, int toIndex, int size) {
1118	<	if (fromIndex < 0)
1119	<	throw new IndexOutOfBoundsException("fromIndex = " + fromIndex);
884	<	if (toIndex > size)
885	<	throw new IndexOutOfBoundsException("toIndex = " + toIndex);
886	<	if (fromIndex > toIndex)
887	<	throw new IllegalArgumentException("fromIndex(" + fromIndex +
888	<	") > toIndex(" + toIndex + ")");
889	<	}
890	<
891	<	private class SubList extends AbstractList<E> implements RandomAccess {
892	<	private final AbstractList<E> parent;
893	<	private final int parentOffset;
1117	>	private static class SubList<E> extends AbstractList<E> implements RandomAccess {
1118	>	private final ArrayList<E> root;
1119	>	private final SubList<E> parent;
1120		private final int offset;
1121		private int size;
1122
1123	<	SubList(AbstractList<E> parent,
1124	<	int offset, int fromIndex, int toIndex) {
1123	>	/**
1124	>	* Constructs a sublist of an arbitrary ArrayList.
1125	>	*/
1126	>	public SubList(ArrayList<E> root, int fromIndex, int toIndex) {
1127	>	this.root = root;
1128	>	this.parent = null;
1129	>	this.offset = fromIndex;
1130	>	this.size = toIndex - fromIndex;
1131	>	this.modCount = root.modCount;
1132	>	}
1133	>
1134	>	/**
1135	>	* Constructs a sublist of another SubList.
1136	>	*/
1137	>	private SubList(SubList<E> parent, int fromIndex, int toIndex) {
1138	>	this.root = parent.root;
1139		this.parent = parent;
1140	<	this.parentOffset = fromIndex;
901	<	this.offset = offset + fromIndex;
1140	>	this.offset = parent.offset + fromIndex;
1141		this.size = toIndex - fromIndex;
1142	<	this.modCount = ArrayList.this.modCount;
1142	>	this.modCount = root.modCount;
1143		}
1144
1145	<	public E set(int index, E e) {
1146	<	rangeCheck(index);
1145	>	public E set(int index, E element) {
1146	>	Objects.checkIndex(index, size);
1147		checkForComodification();
1148	<	E oldValue = ArrayList.this.elementData(offset + index);
1149	<	ArrayList.this.elementData[offset + index] = e;
1148	>	E oldValue = root.elementData(offset + index);
1149	>	root.elementData[offset + index] = element;
1150		return oldValue;
1151		}
1152
1153		public E get(int index) {
1154	<	rangeCheck(index);
1154	>	Objects.checkIndex(index, size);
1155		checkForComodification();
1156	<	return ArrayList.this.elementData(offset + index);
1156	>	return root.elementData(offset + index);
1157		}
1158
1159		public int size() {
1160		checkForComodification();
1161	<	return this.size;
1161	>	return size;
1162		}
1163
1164	<	public void add(int index, E e) {
1164	>	public void add(int index, E element) {
1165		rangeCheckForAdd(index);
1166		checkForComodification();
1167	<	parent.add(parentOffset + index, e);
1168	<	this.modCount = parent.modCount;
930	<	this.size++;
1167	>	root.add(offset + index, element);
1168	>	updateSizeAndModCount(1);
1169		}
1170
1171		public E remove(int index) {
1172	<	rangeCheck(index);
1172	>	Objects.checkIndex(index, size);
1173		checkForComodification();
1174	<	E result = parent.remove(parentOffset + index);
1175	<	this.modCount = parent.modCount;
938	<	this.size--;
1174	>	E result = root.remove(offset + index);
1175	>	updateSizeAndModCount(-1);
1176		return result;
1177		}
1178
1179		protected void removeRange(int fromIndex, int toIndex) {
1180		checkForComodification();
1181	<	parent.removeRange(parentOffset + fromIndex,
1182	<	parentOffset + toIndex);
946	<	this.modCount = parent.modCount;
947	<	this.size -= toIndex - fromIndex;
1181	>	root.removeRange(offset + fromIndex, offset + toIndex);
1182	>	updateSizeAndModCount(fromIndex - toIndex);
1183		}
1184
1185		public boolean addAll(Collection<? extends E> c) {
#	Line 956 | Line 1191 | public class ArrayList<E> extends Abstra
1191		int cSize = c.size();
1192		if (cSize==0)
1193		return false;
959	–
1194		checkForComodification();
1195	<	parent.addAll(parentOffset + index, c);
1196	<	this.modCount = parent.modCount;
963	<	this.size += cSize;
1195	>	root.addAll(offset + index, c);
1196	>	updateSizeAndModCount(cSize);
1197		return true;
1198		}
1199
1200	+	public void replaceAll(UnaryOperator<E> operator) {
1201	+	root.replaceAllRange(operator, offset, offset + size);
1202	+	}
1203	+
1204	+	public boolean removeAll(Collection<?> c) {
1205	+	return batchRemove(c, false);
1206	+	}
1207	+
1208	+	public boolean retainAll(Collection<?> c) {
1209	+	return batchRemove(c, true);
1210	+	}
1211	+
1212	+	private boolean batchRemove(Collection<?> c, boolean complement) {
1213	+	checkForComodification();
1214	+	int oldSize = root.size;
1215	+	boolean modified =
1216	+	root.batchRemove(c, complement, offset, offset + size);
1217	+	if (modified)
1218	+	updateSizeAndModCount(root.size - oldSize);
1219	+	return modified;
1220	+	}
1221	+
1222	+	public boolean removeIf(Predicate<? super E> filter) {
1223	+	checkForComodification();
1224	+	int oldSize = root.size;
1225	+	boolean modified = root.removeIf(filter, offset, offset + size);
1226	+	if (modified)
1227	+	updateSizeAndModCount(root.size - oldSize);
1228	+	return modified;
1229	+	}
1230	+
1231	+	public Object[] toArray() {
1232	+	checkForComodification();
1233	+	return Arrays.copyOfRange(root.elementData, offset, offset + size);
1234	+	}
1235	+
1236	+	@SuppressWarnings("unchecked")
1237	+	public <T> T[] toArray(T[] a) {
1238	+	checkForComodification();
1239	+	if (a.length < size)
1240	+	return (T[]) Arrays.copyOfRange(
1241	+	root.elementData, offset, offset + size, a.getClass());
1242	+	System.arraycopy(root.elementData, offset, a, 0, size);
1243	+	if (a.length > size)
1244	+	a[size] = null;
1245	+	return a;
1246	+	}
1247	+
1248	+	public boolean equals(Object o) {
1249	+	if (o == this) {
1250	+	return true;
1251	+	}
1252	+
1253	+	if (!(o instanceof List)) {
1254	+	return false;
1255	+	}
1256	+
1257	+	boolean equal = root.equalsRange((List<?>)o, offset, offset + size);
1258	+	checkForComodification();
1259	+	return equal;
1260	+	}
1261	+
1262	+	public int hashCode() {
1263	+	int hash = root.hashCodeRange(offset, offset + size);
1264	+	checkForComodification();
1265	+	return hash;
1266	+	}
1267	+
1268	+	public int indexOf(Object o) {
1269	+	int index = root.indexOfRange(o, offset, offset + size);
1270	+	checkForComodification();
1271	+	return index >= 0 ? index - offset : -1;
1272	+	}
1273	+
1274	+	public int lastIndexOf(Object o) {
1275	+	int index = root.lastIndexOfRange(o, offset, offset + size);
1276	+	checkForComodification();
1277	+	return index >= 0 ? index - offset : -1;
1278	+	}
1279	+
1280	+	public boolean contains(Object o) {
1281	+	return indexOf(o) >= 0;
1282	+	}
1283	+
1284		public Iterator<E> iterator() {
1285		return listIterator();
1286		}
1287
1288	<	public ListIterator<E> listIterator(final int index) {
1288	>	public ListIterator<E> listIterator(int index) {
1289		checkForComodification();
1290		rangeCheckForAdd(index);
1291
1292		return new ListIterator<E>() {
1293		int cursor = index;
1294		int lastRet = -1;
1295	<	int expectedModCount = ArrayList.this.modCount;
1295	>	int expectedModCount = root.modCount;
1296
1297		public boolean hasNext() {
1298		return cursor != SubList.this.size;
#	Line 987 | Line 1304 | public class ArrayList<E> extends Abstra
1304		int i = cursor;
1305		if (i >= SubList.this.size)
1306		throw new NoSuchElementException();
1307	<	Object[] elementData = ArrayList.this.elementData;
1307	>	Object[] elementData = root.elementData;
1308		if (offset + i >= elementData.length)
1309		throw new ConcurrentModificationException();
1310		cursor = i + 1;
#	Line 1004 | Line 1321 | public class ArrayList<E> extends Abstra
1321		int i = cursor - 1;
1322		if (i < 0)
1323		throw new NoSuchElementException();
1324	<	Object[] elementData = ArrayList.this.elementData;
1324	>	Object[] elementData = root.elementData;
1325		if (offset + i >= elementData.length)
1326		throw new ConcurrentModificationException();
1327		cursor = i;
1328		return (E) elementData[offset + (lastRet = i)];
1329		}
1330
1331	+	public void forEachRemaining(Consumer<? super E> action) {
1332	+	Objects.requireNonNull(action);
1333	+	final int size = SubList.this.size;
1334	+	int i = cursor;
1335	+	if (i < size) {
1336	+	final Object[] es = root.elementData;
1337	+	if (offset + i >= es.length)
1338	+	throw new ConcurrentModificationException();
1339	+	for (; i < size && modCount == expectedModCount; i++)
1340	+	action.accept(elementAt(es, offset + i));
1341	+	// update once at end to reduce heap write traffic
1342	+	cursor = i;
1343	+	lastRet = i - 1;
1344	+	checkForComodification();
1345	+	}
1346	+	}
1347	+
1348		public int nextIndex() {
1349		return cursor;
1350		}
#	Line 1028 | Line 1362 | public class ArrayList<E> extends Abstra
1362		SubList.this.remove(lastRet);
1363		cursor = lastRet;
1364		lastRet = -1;
1365	<	expectedModCount = ArrayList.this.modCount;
1365	>	expectedModCount = root.modCount;
1366		} catch (IndexOutOfBoundsException ex) {
1367		throw new ConcurrentModificationException();
1368		}
#	Line 1040 | Line 1374 | public class ArrayList<E> extends Abstra
1374		checkForComodification();
1375
1376		try {
1377	<	ArrayList.this.set(offset + lastRet, e);
1377	>	root.set(offset + lastRet, e);
1378		} catch (IndexOutOfBoundsException ex) {
1379		throw new ConcurrentModificationException();
1380		}
#	Line 1054 | Line 1388 | public class ArrayList<E> extends Abstra
1388		SubList.this.add(i, e);
1389		cursor = i + 1;
1390		lastRet = -1;
1391	<	expectedModCount = ArrayList.this.modCount;
1391	>	expectedModCount = root.modCount;
1392		} catch (IndexOutOfBoundsException ex) {
1393		throw new ConcurrentModificationException();
1394		}
1395		}
1396
1397		final void checkForComodification() {
1398	<	if (expectedModCount != ArrayList.this.modCount)
1398	>	if (root.modCount != expectedModCount)
1399		throw new ConcurrentModificationException();
1400		}
1401		};
#	Line 1069 | Line 1403 | public class ArrayList<E> extends Abstra
1403
1404		public List<E> subList(int fromIndex, int toIndex) {
1405		subListRangeCheck(fromIndex, toIndex, size);
1406	<	return new SubList(this, offset, fromIndex, toIndex);
1073	<	}
1074	<
1075	<	private void rangeCheck(int index) {
1076	<	if (index < 0 || index >= this.size)
1077	<	throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
1406	>	return new SubList<>(this, fromIndex, toIndex);
1407		}
1408
1409		private void rangeCheckForAdd(int index) {
#	Line 1087 | Line 1416 | public class ArrayList<E> extends Abstra
1416		}
1417
1418		private void checkForComodification() {
1419	<	if (ArrayList.this.modCount != this.modCount)
1419	>	if (root.modCount != modCount)
1420		throw new ConcurrentModificationException();
1421		}
1422	+
1423	+	private void updateSizeAndModCount(int sizeChange) {
1424	+	SubList<E> slist = this;
1425	+	do {
1426	+	slist.size += sizeChange;
1427	+	slist.modCount = root.modCount;
1428	+	slist = slist.parent;
1429	+	} while (slist != null);
1430	+	}
1431	+
1432	+	public Spliterator<E> spliterator() {
1433	+	checkForComodification();
1434	+
1435	+	// ArrayListSpliterator not used here due to late-binding
1436	+	return new Spliterator<E>() {
1437	+	private int index = offset; // current index, modified on advance/split
1438	+	private int fence = -1; // -1 until used; then one past last index
1439	+	private int expectedModCount; // initialized when fence set
1440	+
1441	+	private int getFence() { // initialize fence to size on first use
1442	+	int hi; // (a specialized variant appears in method forEach)
1443	+	if ((hi = fence) < 0) {
1444	+	expectedModCount = modCount;
1445	+	hi = fence = offset + size;
1446	+	}
1447	+	return hi;
1448	+	}
1449	+
1450	+	public ArrayList<E>.ArrayListSpliterator trySplit() {
1451	+	int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
1452	+	// ArrayListSpliterator can be used here as the source is already bound
1453	+	return (lo >= mid) ? null : // divide range in half unless too small
1454	+	root.new ArrayListSpliterator(lo, index = mid, expectedModCount);
1455	+	}
1456	+
1457	+	public boolean tryAdvance(Consumer<? super E> action) {
1458	+	Objects.requireNonNull(action);
1459	+	int hi = getFence(), i = index;
1460	+	if (i < hi) {
1461	+	index = i + 1;
1462	+	@SuppressWarnings("unchecked") E e = (E)root.elementData[i];
1463	+	action.accept(e);
1464	+	if (root.modCount != expectedModCount)
1465	+	throw new ConcurrentModificationException();
1466	+	return true;
1467	+	}
1468	+	return false;
1469	+	}
1470	+
1471	+	public void forEachRemaining(Consumer<? super E> action) {
1472	+	Objects.requireNonNull(action);
1473	+	int i, hi, mc; // hoist accesses and checks from loop
1474	+	ArrayList<E> lst = root;
1475	+	Object[] a;
1476	+	if ((a = lst.elementData) != null) {
1477	+	if ((hi = fence) < 0) {
1478	+	mc = modCount;
1479	+	hi = offset + size;
1480	+	}
1481	+	else
1482	+	mc = expectedModCount;
1483	+	if ((i = index) >= 0 && (index = hi) <= a.length) {
1484	+	for (; i < hi; ++i) {
1485	+	@SuppressWarnings("unchecked") E e = (E) a[i];
1486	+	action.accept(e);
1487	+	}
1488	+	if (lst.modCount == mc)
1489	+	return;
1490	+	}
1491	+	}
1492	+	throw new ConcurrentModificationException();
1493	+	}
1494	+
1495	+	public long estimateSize() {
1496	+	return getFence() - index;
1497	+	}
1498	+
1499	+	public int characteristics() {
1500	+	return Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED;
1501	+	}
1502	+	};
1503	+	}
1504	+	}
1505	+
1506	+	/**
1507	+	* @throws NullPointerException {@inheritDoc}
1508	+	*/
1509	+	@Override
1510	+	public void forEach(Consumer<? super E> action) {
1511	+	Objects.requireNonNull(action);
1512	+	final int expectedModCount = modCount;
1513	+	final Object[] es = elementData;
1514	+	final int size = this.size;
1515	+	for (int i = 0; modCount == expectedModCount && i < size; i++)
1516	+	action.accept(elementAt(es, i));
1517	+	if (modCount != expectedModCount)
1518	+	throw new ConcurrentModificationException();
1519	+	}
1520	+
1521	+	/**
1522	+	* Creates a <em><a href="Spliterator.html#binding">late-binding</a></em>
1523	+	* and <em>fail-fast</em> {@link Spliterator} over the elements in this
1524	+	* list.
1525	+	*
1526	+	* <p>The {@code Spliterator} reports {@link Spliterator#SIZED},
1527	+	* {@link Spliterator#SUBSIZED}, and {@link Spliterator#ORDERED}.
1528	+	* Overriding implementations should document the reporting of additional
1529	+	* characteristic values.
1530	+	*
1531	+	* @return a {@code Spliterator} over the elements in this list
1532	+	* @since 1.8
1533	+	*/
1534	+	@Override
1535	+	public Spliterator<E> spliterator() {
1536	+	return new ArrayListSpliterator(0, -1, 0);
1537	+	}
1538	+
1539	+	/** Index-based split-by-two, lazily initialized Spliterator */
1540	+	final class ArrayListSpliterator implements Spliterator<E> {
1541	+
1542	+	/*
1543	+	* If ArrayLists were immutable, or structurally immutable (no
1544	+	* adds, removes, etc), we could implement their spliterators
1545	+	* with Arrays.spliterator. Instead we detect as much
1546	+	* interference during traversal as practical without
1547	+	* sacrificing much performance. We rely primarily on
1548	+	* modCounts. These are not guaranteed to detect concurrency
1549	+	* violations, and are sometimes overly conservative about
1550	+	* within-thread interference, but detect enough problems to
1551	+	* be worthwhile in practice. To carry this out, we (1) lazily
1552	+	* initialize fence and expectedModCount until the latest
1553	+	* point that we need to commit to the state we are checking
1554	+	* against; thus improving precision.  (This doesn't apply to
1555	+	* SubLists, that create spliterators with current non-lazy
1556	+	* values).  (2) We perform only a single
1557	+	* ConcurrentModificationException check at the end of forEach
1558	+	* (the most performance-sensitive method). When using forEach
1559	+	* (as opposed to iterators), we can normally only detect
1560	+	* interference after actions, not before. Further
1561	+	* CME-triggering checks apply to all other possible
1562	+	* violations of assumptions for example null or too-small
1563	+	* elementData array given its size(), that could only have
1564	+	* occurred due to interference.  This allows the inner loop
1565	+	* of forEach to run without any further checks, and
1566	+	* simplifies lambda-resolution. While this does entail a
1567	+	* number of checks, note that in the common case of
1568	+	* list.stream().forEach(a), no checks or other computation
1569	+	* occur anywhere other than inside forEach itself.  The other
1570	+	* less-often-used methods cannot take advantage of most of
1571	+	* these streamlinings.
1572	+	*/
1573	+
1574	+	private int index; // current index, modified on advance/split
1575	+	private int fence; // -1 until used; then one past last index
1576	+	private int expectedModCount; // initialized when fence set
1577	+
1578	+	/** Creates new spliterator covering the given range. */
1579	+	ArrayListSpliterator(int origin, int fence, int expectedModCount) {
1580	+	this.index = origin;
1581	+	this.fence = fence;
1582	+	this.expectedModCount = expectedModCount;
1583	+	}
1584	+
1585	+	private int getFence() { // initialize fence to size on first use
1586	+	int hi; // (a specialized variant appears in method forEach)
1587	+	if ((hi = fence) < 0) {
1588	+	expectedModCount = modCount;
1589	+	hi = fence = size;
1590	+	}
1591	+	return hi;
1592	+	}
1593	+
1594	+	public ArrayListSpliterator trySplit() {
1595	+	int hi = getFence(), lo = index, mid = (lo + hi) >>> 1;
1596	+	return (lo >= mid) ? null : // divide range in half unless too small
1597	+	new ArrayListSpliterator(lo, index = mid, expectedModCount);
1598	+	}
1599	+
1600	+	public boolean tryAdvance(Consumer<? super E> action) {
1601	+	if (action == null)
1602	+	throw new NullPointerException();
1603	+	int hi = getFence(), i = index;
1604	+	if (i < hi) {
1605	+	index = i + 1;
1606	+	@SuppressWarnings("unchecked") E e = (E)elementData[i];
1607	+	action.accept(e);
1608	+	if (modCount != expectedModCount)
1609	+	throw new ConcurrentModificationException();
1610	+	return true;
1611	+	}
1612	+	return false;
1613	+	}
1614	+
1615	+	public void forEachRemaining(Consumer<? super E> action) {
1616	+	int i, hi, mc; // hoist accesses and checks from loop
1617	+	Object[] a;
1618	+	if (action == null)
1619	+	throw new NullPointerException();
1620	+	if ((a = elementData) != null) {
1621	+	if ((hi = fence) < 0) {
1622	+	mc = modCount;
1623	+	hi = size;
1624	+	}
1625	+	else
1626	+	mc = expectedModCount;
1627	+	if ((i = index) >= 0 && (index = hi) <= a.length) {
1628	+	for (; i < hi; ++i) {
1629	+	@SuppressWarnings("unchecked") E e = (E) a[i];
1630	+	action.accept(e);
1631	+	}
1632	+	if (modCount == mc)
1633	+	return;
1634	+	}
1635	+	}
1636	+	throw new ConcurrentModificationException();
1637	+	}
1638	+
1639	+	public long estimateSize() {
1640	+	return getFence() - index;
1641	+	}
1642	+
1643	+	public int characteristics() {
1644	+	return Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED;
1645	+	}
1646	+	}
1647	+
1648	+	// A tiny bit set implementation
1649	+
1650	+	private static long[] nBits(int n) {
1651	+	return new long[((n - 1) >> 6) + 1];
1652	+	}
1653	+	private static void setBit(long[] bits, int i) {
1654	+	bits[i >> 6] |= 1L << i;
1655	+	}
1656	+	private static boolean isClear(long[] bits, int i) {
1657	+	return (bits[i >> 6] & (1L << i)) == 0;
1658	+	}
1659	+
1660	+	/**
1661	+	* @throws NullPointerException {@inheritDoc}
1662	+	*/
1663	+	@Override
1664	+	public boolean removeIf(Predicate<? super E> filter) {
1665	+	return removeIf(filter, 0, size);
1666	+	}
1667	+
1668	+	/**
1669	+	* Removes all elements satisfying the given predicate, from index
1670	+	* i (inclusive) to index end (exclusive).
1671	+	*/
1672	+	boolean removeIf(Predicate<? super E> filter, int i, final int end) {
1673	+	Objects.requireNonNull(filter);
1674	+	int expectedModCount = modCount;
1675	+	final Object[] es = elementData;
1676	+	// Optimize for initial run of survivors
1677	+	for (; i < end && !filter.test(elementAt(es, i)); i++)
1678	+	;
1679	+	// Tolerate predicates that reentrantly access the collection for
1680	+	// read (but writers still get CME), so traverse once to find
1681	+	// elements to delete, a second pass to physically expunge.
1682	+	if (i < end) {
1683	+	final int beg = i;
1684	+	final long[] deathRow = nBits(end - beg);
1685	+	deathRow[0] = 1L;   // set bit 0
1686	+	for (i = beg + 1; i < end; i++)
1687	+	if (filter.test(elementAt(es, i)))
1688	+	setBit(deathRow, i - beg);
1689	+	if (modCount != expectedModCount)
1690	+	throw new ConcurrentModificationException();
1691	+	modCount++;
1692	+	int w = beg;
1693	+	for (i = beg; i < end; i++)
1694	+	if (isClear(deathRow, i - beg))
1695	+	es[w++] = es[i];
1696	+	shiftTailOverGap(es, w, end);
1697	+	// checkInvariants();
1698	+	return true;
1699	+	} else {
1700	+	if (modCount != expectedModCount)
1701	+	throw new ConcurrentModificationException();
1702	+	// checkInvariants();
1703	+	return false;
1704	+	}
1705	+	}
1706	+
1707	+	@Override
1708	+	public void replaceAll(UnaryOperator<E> operator) {
1709	+	replaceAllRange(operator, 0, size);
1710	+	// TODO(8203662): remove increment of modCount from ...
1711	+	modCount++;
1712	+	}
1713	+
1714	+	private void replaceAllRange(UnaryOperator<E> operator, int i, int end) {
1715	+	Objects.requireNonNull(operator);
1716	+	final int expectedModCount = modCount;
1717	+	final Object[] es = elementData;
1718	+	for (; modCount == expectedModCount && i < end; i++)
1719	+	es[i] = operator.apply(elementAt(es, i));
1720	+	if (modCount != expectedModCount)
1721	+	throw new ConcurrentModificationException();
1722	+	// checkInvariants();
1723	+	}
1724	+
1725	+	@Override
1726	+	@SuppressWarnings("unchecked")
1727	+	public void sort(Comparator<? super E> c) {
1728	+	final int expectedModCount = modCount;
1729	+	Arrays.sort((E[]) elementData, 0, size, c);
1730	+	if (modCount != expectedModCount)
1731	+	throw new ConcurrentModificationException();
1732	+	modCount++;
1733	+	// checkInvariants();
1734	+	}
1735	+
1736	+	void checkInvariants() {
1737	+	// assert size >= 0;
1738	+	// assert size == elementData.length || elementData[size] == null;
1739		}
1740		}

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