8223593: Refactor code for reallocating storage

Reviewed-by: prappo, plevart, rriggs, smarks
This commit is contained in:
Ivan Gerasimov 2019-05-21 18:40:29 -07:00
parent 54d0b2a8d6
commit 218204b1a3
11 changed files with 129 additions and 247 deletions

View file

@ -1,5 +1,5 @@
/*
* Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2003, 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
@ -28,6 +28,7 @@ package java.util;
import java.util.function.Consumer;
import java.util.function.Predicate;
import jdk.internal.access.SharedSecrets;
import jdk.internal.util.ArraysSupport;
/**
* An unbounded priority {@linkplain Queue queue} based on a priority heap.
@ -281,14 +282,6 @@ public class PriorityQueue<E> extends AbstractQueue<E>
heapify();
}
/**
* The maximum size of array to allocate.
* 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 of the array.
*
@ -297,23 +290,13 @@ public class PriorityQueue<E> extends AbstractQueue<E>
private void grow(int minCapacity) {
int oldCapacity = queue.length;
// Double size if small; else grow by 50%
int newCapacity = oldCapacity + ((oldCapacity < 64) ?
(oldCapacity + 2) :
(oldCapacity >> 1));
// overflow-conscious code
if (newCapacity - MAX_ARRAY_SIZE > 0)
newCapacity = hugeCapacity(minCapacity);
int newCapacity = ArraysSupport.newLength(oldCapacity,
minCapacity - oldCapacity, /* minimum growth */
oldCapacity < 64 ? oldCapacity + 2 : oldCapacity >> 1
/* preferred growth */);
queue = Arrays.copyOf(queue, newCapacity);
}
private static int hugeCapacity(int minCapacity) {
if (minCapacity < 0) // overflow
throw new OutOfMemoryError();
return (minCapacity > MAX_ARRAY_SIZE) ?
Integer.MAX_VALUE :
MAX_ARRAY_SIZE;
}
/**
* Inserts the specified element into this priority queue.
*