87 lines
2.7 KiB
Java
87 lines
2.7 KiB
Java
/*
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* Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package gc.g1.plab.lib;
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/**
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* The MemoryConsumer is used for consuming different amount of memory.
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* Class will store not more than 'capacity' number of objects with 'chunk' size.
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* If we exceed capacity, object will be stored at existing entries,
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* all previously added objects will be overwritten.
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* If capacity=1, only last object will be saved.
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*/
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public class MemoryConsumer {
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private int capacity;
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private int chunk;
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private Object[] array;
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private int index;
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/**
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* Create MemoryConsumer object with defined capacity
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*
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* @param capacity
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* @param chunk
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*/
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public MemoryConsumer(int capacity, int chunk) {
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if (capacity <= 0) {
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throw new IllegalArgumentException("Items number should be greater than 0.");
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}
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if (chunk <= 0) {
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throw new IllegalArgumentException("Chunk size should be greater than 0.");
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}
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this.capacity = capacity;
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this.chunk = chunk;
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index = 0;
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array = new Object[this.capacity];
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}
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/**
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* Store object into MemoryConsumer.
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*
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* @param o - Object to store
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*/
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private void store(Object o) {
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if (array == null) {
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throw new RuntimeException("Capacity should be set before storing");
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}
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array[index % capacity] = o;
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++index;
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}
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public void consume(long memoryToFill) {
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long allocated = 0;
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while (allocated < memoryToFill) {
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store(new byte[chunk]);
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allocated += chunk;
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}
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}
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/**
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* Clear all stored objects.
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*/
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public void clear() {
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array = null;
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}
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}
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