116 lines
3.8 KiB
Java
116 lines
3.8 KiB
Java
/*
|
|
* Copyright (c) 2015, 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
|
|
* under the terms of the GNU General Public License version 2 only, as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This code is distributed in the hope that it will be useful, but WITHOUT
|
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
* version 2 for more details (a copy is included in the LICENSE file that
|
|
* accompanied this code).
|
|
*
|
|
* You should have received a copy of the GNU General Public License version
|
|
* 2 along with this work; if not, write to the Free Software Foundation,
|
|
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*
|
|
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
|
|
* or visit www.oracle.com if you need additional information or have any
|
|
* questions.
|
|
*/
|
|
|
|
package gc.arguments;
|
|
|
|
import java.util.concurrent.Callable;
|
|
|
|
/**
|
|
* Helper class which allocates memory.
|
|
*
|
|
* Typical usage:
|
|
* <pre>
|
|
* {@code
|
|
* AllocationHelper allocator = new AllocationHelper(MAX_ITERATIONS, ARRAY_LENGTH, CHUNK_SIZE,
|
|
* () -> (verifier()));
|
|
* // Allocate byte[CHUNK_SIZE] ARRAY_LENGTH times. Total allocated bytes will be CHUNK_SIZE * ARRAY_LENGTH + refs length.
|
|
* // Then invoke verifier and iterate MAX_ITERATIONS times.
|
|
* allocator.allocateMemoryAndVerify();
|
|
* }
|
|
* </pre>
|
|
*/
|
|
public final class AllocationHelper {
|
|
|
|
private final int arrayLength;
|
|
private final int maxIterations;
|
|
private final int chunkSize;
|
|
|
|
// garbageStorage is used to store link to garbage to prevent optimization.
|
|
private static Object garbageStorage;
|
|
private byte garbage[][];
|
|
private final Callable<?> verifierInstance;
|
|
|
|
/**
|
|
* Create an AllocationHelper with specified iteration count, array length, chunk size and verifier.
|
|
*
|
|
* @param maxIterations
|
|
* @param arrayLength
|
|
* @param chunkSize
|
|
* @param verifier - Callable instance which will be invoked after all allocation cycle. Can be null;
|
|
*/
|
|
public AllocationHelper(int maxIterations, int arrayLength, int chunkSize, Callable<?> verifier) {
|
|
if ((arrayLength <= 0) || (maxIterations <= 0) || (chunkSize <= 0)) {
|
|
throw new IllegalArgumentException("maxIterations, arrayLength and chunkSize should be greater then 0.");
|
|
}
|
|
this.arrayLength = arrayLength;
|
|
this.maxIterations = maxIterations;
|
|
this.chunkSize = chunkSize;
|
|
verifierInstance = verifier;
|
|
garbage = new byte[this.arrayLength][];
|
|
garbageStorage = garbage;
|
|
}
|
|
|
|
private void allocateMemoryOneIteration() {
|
|
for (int j = 0; j < arrayLength; j++) {
|
|
garbage[j] = new byte[chunkSize];
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Allocate memory and invoke Verifier during all iteration.
|
|
*
|
|
* @throws java.lang.Exception
|
|
*/
|
|
public void allocateMemoryAndVerify() throws Exception {
|
|
for (int i = 0; i < maxIterations; i++) {
|
|
allocateMemoryOneIteration();
|
|
if (verifierInstance != null) {
|
|
verifierInstance.call();
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* The same as allocateMemoryAndVerify() but hides OOME
|
|
*
|
|
* @throws Exception
|
|
*/
|
|
public void allocateMemoryAndVerifyNoOOME() throws Exception {
|
|
try {
|
|
allocateMemoryAndVerify();
|
|
} catch (OutOfMemoryError e) {
|
|
// exit on OOME
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Release link to allocated garbage to make it available for further GC
|
|
*/
|
|
public void release() {
|
|
if (garbage != null) {
|
|
garbage = null;
|
|
garbageStorage = null;
|
|
}
|
|
}
|
|
}
|