--- jsr166/src/main/java/util/ArrayList.java 2016/11/30 03:31:47 1.45
+++ jsr166/src/main/java/util/ArrayList.java 2018/01/08 21:51:07 1.55
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2017, 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
@@ -28,6 +28,7 @@ package java.util;
import java.util.function.Consumer;
import java.util.function.Predicate;
import java.util.function.UnaryOperator;
+import jdk.internal.misc.SharedSecrets;
/**
* Resizable-array implementation of the {@code List} interface. Implements
@@ -91,7 +92,7 @@ import java.util.function.UnaryOperator;
* should be used only to detect bugs.
*
*
This class is a member of the
- *
+ *
* Java Collections Framework.
*
* @param the type of elements in this list
@@ -515,15 +516,10 @@ public class ArrayList extends Abstra
*/
public E remove(int index) {
Objects.checkIndex(index, size);
+ final Object[] es = elementData;
- modCount++;
- E oldValue = elementData(index);
-
- int numMoved = size - index - 1;
- if (numMoved > 0)
- System.arraycopy(elementData, index+1, elementData, index,
- numMoved);
- elementData[--size] = null; // clear to let GC do its work
+ @SuppressWarnings("unchecked") E oldValue = (E) es[index];
+ fastRemove(es, index);
// checkInvariants();
return oldValue;
@@ -543,33 +539,35 @@ public class ArrayList extends Abstra
* @return {@code true} if this list contained the specified element
*/
public boolean remove(Object o) {
- if (o == null) {
- for (int index = 0; index < size; index++)
- if (elementData[index] == null) {
- fastRemove(index);
- return true;
- }
- } else {
- for (int index = 0; index < size; index++)
- if (o.equals(elementData[index])) {
- fastRemove(index);
- return true;
- }
+ final Object[] es = elementData;
+ final int size = this.size;
+ int i = 0;
+ found: {
+ if (o == null) {
+ for (; i < size; i++)
+ if (es[i] == null)
+ break found;
+ } else {
+ for (; i < size; i++)
+ if (o.equals(es[i]))
+ break found;
+ }
+ return false;
}
- return false;
+ fastRemove(es, i);
+ return true;
}
/**
* Private remove method that skips bounds checking and does not
* return the value removed.
*/
- private void fastRemove(int index) {
+ private void fastRemove(Object[] es, int i) {
modCount++;
- int numMoved = size - index - 1;
- if (numMoved > 0)
- System.arraycopy(elementData, index+1, elementData, index,
- numMoved);
- elementData[--size] = null; // clear to let GC do its work
+ final int newSize;
+ if ((newSize = size - 1) > i)
+ System.arraycopy(es, i + 1, es, i, newSize - i);
+ es[size = newSize] = null;
}
/**
@@ -578,8 +576,9 @@ public class ArrayList extends Abstra
*/
public void clear() {
modCount++;
- Arrays.fill(elementData, 0, size, null);
- size = 0;
+ final Object[] es = elementData;
+ for (int to = size, i = size = 0; i < to; i++)
+ es[i] = null;
}
/**
@@ -669,13 +668,17 @@ public class ArrayList extends Abstra
outOfBoundsMsg(fromIndex, toIndex));
}
modCount++;
- final Object[] es = elementData;
- final int oldSize = size;
- System.arraycopy(es, toIndex, es, fromIndex, oldSize - toIndex);
- Arrays.fill(es, size -= (toIndex - fromIndex), oldSize, null);
+ shiftTailOverGap(elementData, fromIndex, toIndex);
// checkInvariants();
}
+ /** Erases the gap from lo to hi, by sliding down following elements. */
+ private void shiftTailOverGap(Object[] es, int lo, int hi) {
+ System.arraycopy(es, hi, es, lo, size - hi);
+ for (int to = size, i = (size -= hi - lo); i < to; i++)
+ es[i] = null;
+ }
+
/**
* A version of rangeCheck used by add and addAll.
*/
@@ -743,49 +746,50 @@ public class ArrayList extends Abstra
final int from, final int end) {
Objects.requireNonNull(c);
final Object[] es = elementData;
- final boolean modified;
int r;
// Optimize for initial run of survivors
- for (r = from; r < end && c.contains(es[r]) == complement; r++)
- ;
- if (modified = (r < end)) {
- int w = r++;
- try {
- for (Object e; r < end; r++)
- if (c.contains(e = es[r]) == complement)
- es[w++] = e;
- } catch (Throwable ex) {
- // Preserve behavioral compatibility with AbstractCollection,
- // even if c.contains() throws.
- System.arraycopy(es, r, es, w, end - r);
- w += end - r;
- throw ex;
- } finally {
- final int oldSize = size, deleted = end - w;
- modCount += deleted;
- System.arraycopy(es, end, es, w, oldSize - end);
- Arrays.fill(es, size -= deleted, oldSize, null);
- }
+ for (r = from;; r++) {
+ if (r == end)
+ return false;
+ if (c.contains(es[r]) != complement)
+ break;
+ }
+ int w = r++;
+ try {
+ for (Object e; r < end; r++)
+ if (c.contains(e = es[r]) == complement)
+ es[w++] = e;
+ } catch (Throwable ex) {
+ // Preserve behavioral compatibility with AbstractCollection,
+ // even if c.contains() throws.
+ System.arraycopy(es, r, es, w, end - r);
+ w += end - r;
+ throw ex;
+ } finally {
+ modCount += end - w;
+ shiftTailOverGap(es, w, end);
}
// checkInvariants();
- return modified;
+ return true;
}
/**
- * Save the state of the {@code ArrayList} instance to a stream (that
- * is, serialize it).
+ * Saves the state of the {@code ArrayList} instance to a stream
+ * (that is, serializes it).
*
+ * @param s the stream
+ * @throws java.io.IOException if an I/O error occurs
* @serialData The length of the array backing the {@code ArrayList}
* instance is emitted (int), followed by all of its elements
* (each an {@code Object}) in the proper order.
*/
private void writeObject(java.io.ObjectOutputStream s)
- throws java.io.IOException{
+ throws java.io.IOException {
// Write out element count, and any hidden stuff
int expectedModCount = modCount;
s.defaultWriteObject();
- // Write out size as capacity for behavioural compatibility with clone()
+ // Write out size as capacity for behavioral compatibility with clone()
s.writeInt(size);
// Write out all elements in the proper order.
@@ -799,8 +803,12 @@ public class ArrayList extends Abstra
}
/**
- * Reconstitute the {@code ArrayList} instance from a stream (that is,
- * deserialize it).
+ * Reconstitutes the {@code ArrayList} instance from a stream (that is,
+ * deserializes it).
+ * @param s the stream
+ * @throws ClassNotFoundException if the class of a serialized object
+ * could not be found
+ * @throws java.io.IOException if an I/O error occurs
*/
private void readObject(java.io.ObjectInputStream s)
throws java.io.IOException, ClassNotFoundException {
@@ -813,6 +821,7 @@ public class ArrayList extends Abstra
if (size > 0) {
// like clone(), allocate array based upon size not capacity
+ SharedSecrets.getJavaObjectInputStreamAccess().checkArray(s, Object[].class, size);
Object[] elements = new Object[size];
// Read in all elements in the proper order.
@@ -1362,6 +1371,9 @@ public class ArrayList extends Abstra
}
}
+ /**
+ * @throws NullPointerException {@inheritDoc}
+ */
@Override
public void forEach(Consumer super E> action) {
Objects.requireNonNull(action);
@@ -1431,7 +1443,7 @@ public class ArrayList extends Abstra
private int fence; // -1 until used; then one past last index
private int expectedModCount; // initialized when fence set
- /** Create new spliterator covering the given range */
+ /** Creates new spliterator covering the given range. */
ArrayListSpliterator(int origin, int fence, int expectedModCount) {
this.index = origin;
this.fence = fence;
@@ -1513,6 +1525,9 @@ public class ArrayList extends Abstra
return (bits[i >> 6] & (1L << i)) == 0;
}
+ /**
+ * @throws NullPointerException {@inheritDoc}
+ */
@Override
public boolean removeIf(Predicate super E> filter) {
return removeIf(filter, 0, size);
@@ -1541,15 +1556,12 @@ public class ArrayList extends Abstra
setBit(deathRow, i - beg);
if (modCount != expectedModCount)
throw new ConcurrentModificationException();
- expectedModCount++;
modCount++;
int w = beg;
for (i = beg; i < end; i++)
if (isClear(deathRow, i - beg))
es[w++] = es[i];
- final int oldSize = size;
- System.arraycopy(es, end, es, w, oldSize - end);
- Arrays.fill(es, size -= (end - w), oldSize, null);
+ shiftTailOverGap(es, w, end);
// checkInvariants();
return true;
} else {