--- jsr166/src/main/java/util/ArrayList.java 2018/11/11 16:27:28 1.65 +++ jsr166/src/main/java/util/ArrayList.java 2020/07/24 20:57:26 1.71 @@ -1,5 +1,5 @@ /* - * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it @@ -29,6 +29,7 @@ import java.util.function.Consumer; import java.util.function.Predicate; import java.util.function.UnaryOperator; // OPENJDK import jdk.internal.access.SharedSecrets; +import jdk.internal.util.ArraysSupport; /** * Resizable-array implementation of the {@code List} interface. Implements @@ -108,6 +109,7 @@ import java.util.function.UnaryOperator; public class ArrayList extends AbstractList implements List, RandomAccess, Cloneable, java.io.Serializable { + // OPENJDK @java.io.Serial private static final long serialVersionUID = 8683452581122892189L; /** @@ -176,15 +178,16 @@ public class ArrayList extends Abstra * @throws NullPointerException if the specified collection is null */ public ArrayList(Collection c) { - elementData = c.toArray(); - if ((size = elementData.length) != 0) { - // defend against c.toArray (incorrectly) not returning Object[] - // (see e.g. https://bugs.openjdk.java.net/browse/JDK-6260652) - if (elementData.getClass() != Object[].class) - elementData = Arrays.copyOf(elementData, size, Object[].class); + Object[] a = c.toArray(); + if ((size = a.length) != 0) { + if (c.getClass() == ArrayList.class) { + elementData = a; + } else { + elementData = Arrays.copyOf(a, size, Object[].class); + } } else { // replace with empty array. - this.elementData = EMPTY_ELEMENTDATA; + elementData = EMPTY_ELEMENTDATA; } } @@ -219,14 +222,6 @@ public class ArrayList extends Abstra } /** - * The maximum size of array to allocate (unless necessary). - * Some VMs reserve some header words in an array. - * Attempts to allocate larger arrays may result in - * OutOfMemoryError: Requested array size exceeds VM limit - */ - private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; - - /** * Increases the capacity to ensure that it can hold at least the * number of elements specified by the minimum capacity argument. * @@ -234,8 +229,15 @@ public class ArrayList extends Abstra * @throws OutOfMemoryError if minCapacity is less than zero */ private Object[] grow(int minCapacity) { - return elementData = Arrays.copyOf(elementData, - newCapacity(minCapacity)); + int oldCapacity = elementData.length; + if (oldCapacity > 0 || elementData != DEFAULTCAPACITY_EMPTY_ELEMENTDATA) { + int newCapacity = ArraysSupport.newLength(oldCapacity, + minCapacity - oldCapacity, /* minimum growth */ + oldCapacity >> 1 /* preferred growth */); + return elementData = Arrays.copyOf(elementData, newCapacity); + } else { + return elementData = new Object[Math.max(DEFAULT_CAPACITY, minCapacity)]; + } } private Object[] grow() { @@ -243,39 +245,6 @@ public class ArrayList extends Abstra } /** - * Returns a capacity at least as large as the given minimum capacity. - * Returns the current capacity increased by 50% if that suffices. - * Will not return a capacity greater than MAX_ARRAY_SIZE unless - * the given minimum capacity is greater than MAX_ARRAY_SIZE. - * - * @param minCapacity the desired minimum capacity - * @throws OutOfMemoryError if minCapacity is less than zero - */ - private int newCapacity(int minCapacity) { - // overflow-conscious code - int oldCapacity = elementData.length; - int newCapacity = oldCapacity + (oldCapacity >> 1); - if (newCapacity - minCapacity <= 0) { - if (elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA) - return Math.max(DEFAULT_CAPACITY, minCapacity); - if (minCapacity < 0) // overflow - throw new OutOfMemoryError(); - return minCapacity; - } - return (newCapacity - MAX_ARRAY_SIZE <= 0) - ? newCapacity - : hugeCapacity(minCapacity); - } - - private static int hugeCapacity(int minCapacity) { - if (minCapacity < 0) // overflow - throw new OutOfMemoryError(); - return (minCapacity > MAX_ARRAY_SIZE) - ? Integer.MAX_VALUE - : MAX_ARRAY_SIZE; - } - - /** * Returns the number of elements in this list. * * @return the number of elements in this list @@ -571,7 +540,7 @@ public class ArrayList extends Abstra if (to > es.length) { throw new ConcurrentModificationException(); } - Iterator oit = other.iterator(); + var oit = other.iterator(); for (; from < to; from++) { if (!oit.hasNext() || !Objects.equals(es[from], oit.next())) { return false; @@ -888,6 +857,7 @@ public class ArrayList extends Abstra * instance is emitted (int), followed by all of its elements * (each an {@code Object}) in the proper order. */ + // OPENJDK @java.io.Serial private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException { // Write out element count, and any hidden stuff @@ -915,6 +885,7 @@ public class ArrayList extends Abstra * could not be found * @throws java.io.IOException if an I/O error occurs */ + // OPENJDK @java.io.Serial private void readObject(java.io.ObjectInputStream s) throws java.io.IOException, ClassNotFoundException { @@ -1169,7 +1140,7 @@ public class ArrayList extends Abstra this.parent = parent; this.offset = parent.offset + fromIndex; this.size = toIndex - fromIndex; - this.modCount = root.modCount; + this.modCount = parent.modCount; } public E set(int index, E element) { @@ -1322,7 +1293,7 @@ public class ArrayList extends Abstra return new ListIterator() { int cursor = index; int lastRet = -1; - int expectedModCount = root.modCount; + int expectedModCount = SubList.this.modCount; public boolean hasNext() { return cursor != SubList.this.size; @@ -1366,7 +1337,7 @@ public class ArrayList extends Abstra final Object[] es = root.elementData; if (offset + i >= es.length) throw new ConcurrentModificationException(); - for (; i < size && modCount == expectedModCount; i++) + for (; i < size && root.modCount == expectedModCount; i++) action.accept(elementAt(es, offset + i)); // update once at end to reduce heap write traffic cursor = i; @@ -1392,7 +1363,7 @@ public class ArrayList extends Abstra SubList.this.remove(lastRet); cursor = lastRet; lastRet = -1; - expectedModCount = root.modCount; + expectedModCount = SubList.this.modCount; } catch (IndexOutOfBoundsException ex) { throw new ConcurrentModificationException(); } @@ -1418,7 +1389,7 @@ public class ArrayList extends Abstra SubList.this.add(i, e); cursor = i + 1; lastRet = -1; - expectedModCount = root.modCount; + expectedModCount = SubList.this.modCount; } catch (IndexOutOfBoundsException ex) { throw new ConcurrentModificationException(); } @@ -1737,6 +1708,8 @@ public class ArrayList extends Abstra @Override public void replaceAll(UnaryOperator operator) { replaceAllRange(operator, 0, size); + // TODO(8203662): remove increment of modCount from ... + modCount++; } private void replaceAllRange(UnaryOperator operator, int i, int end) {