| /* |
| * Copyright (c) 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 |
| * 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 utils; |
| |
| import java.lang.management.ManagementFactory; |
| import java.lang.management.MemoryMXBean; |
| import java.lang.management.MemoryPoolMXBean; |
| import java.lang.management.MemoryUsage; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * This is an class used to allocate specified amount of metaspace and heap. |
| */ |
| public class GarbageProducer { |
| |
| // Uses fixed small objects to avoid Humongous objects allocation with G1 GC. |
| private static final int MEMORY_CHUNK = 2048; |
| |
| public static List<Object> allocatedMetaspace; |
| public static List<Object> allocatedMemory; |
| |
| private final MemoryMXBean memoryMXBean; |
| private final float targetMemoryUsagePercent; |
| private final long targetMemoryUsage; |
| |
| /** |
| * @param targetMemoryUsagePercent how many percent of metaspace and heap to |
| * allocate |
| */ |
| public GarbageProducer(float targetMemoryUsagePercent) { |
| memoryMXBean = ManagementFactory.getMemoryMXBean(); |
| this.targetMemoryUsagePercent = targetMemoryUsagePercent; |
| targetMemoryUsage = (long) (memoryMXBean.getHeapMemoryUsage().getMax() * targetMemoryUsagePercent); |
| } |
| |
| /** |
| * Allocates heap and metaspace upon exit targetMemoryUsagePercent percents |
| * of heap and metaspace have been consumed. |
| */ |
| public void allocateMetaspaceAndHeap() { |
| // Metaspace should be filled before Java Heap to prevent unexpected OOME |
| // in the Java Heap while filling Metaspace |
| allocatedMetaspace = eatMetaspace(targetMemoryUsagePercent); |
| allocatedMemory = allocateGarbage(targetMemoryUsage); |
| } |
| |
| private List<Object> eatMetaspace(float targetUsage) { |
| List<Object> list = new ArrayList<>(); |
| MemoryPoolMXBean metaspacePool = getMatchedMemoryPool(".*Metaspace.*"); |
| float currentUsage; |
| GeneratedClassProducer gp = new GeneratedClassProducer(); |
| do { |
| try { |
| list.add(gp.create(0)); |
| } catch (OutOfMemoryError oome) { |
| list = null; |
| throw new RuntimeException("Unexpected OOME '" + oome.getMessage() + "' while eating " + targetUsage + " of Metaspace."); |
| } |
| MemoryUsage memoryUsage = metaspacePool.getUsage(); |
| currentUsage = (((float) memoryUsage.getUsed()) / memoryUsage.getMax()); |
| } while (currentUsage < targetUsage); |
| return list; |
| } |
| |
| private MemoryPoolMXBean getMatchedMemoryPool(String patternPoolName) { |
| return ManagementFactory.getMemoryPoolMXBeans().stream() |
| .filter(bean -> bean.getName().matches(patternPoolName)) |
| .findFirst() |
| .orElseThrow(() -> new RuntimeException("Cannot find '" + patternPoolName + "' memory pool.")); |
| } |
| |
| private List<Object> allocateGarbage(long targetMemoryUsage) { |
| List<Object> list = new ArrayList<>(); |
| do { |
| try { |
| list.add(new byte[MEMORY_CHUNK]); |
| } catch (OutOfMemoryError e) { |
| list = null; |
| throw new RuntimeException("Unexpected OOME '" + e.getMessage() + "'"); |
| } |
| } while (memoryMXBean.getHeapMemoryUsage().getUsed() < targetMemoryUsage); |
| return list; |
| } |
| |
| /** |
| * Returns allocation rate for old gen based on appropriate MemoryPoolMXBean |
| * memory usage. |
| * |
| * @return allocation rate |
| */ |
| public float getOldGenAllocationRatio() { |
| MemoryPoolMXBean oldGenBean = getMatchedMemoryPool(".*Old.*|.*Tenured.*"); |
| MemoryUsage usage = oldGenBean.getUsage(); |
| System.out.format("Memory usage for %1s.\n", oldGenBean.getName()); |
| System.out.format("Used: %1d\n", usage.getUsed()); |
| System.out.format("Commited: %1d\n", usage.getCommitted()); |
| System.out.format("Max: %1d\n", usage.getMax()); |
| return ((float) usage.getUsed()) / usage.getCommitted(); |
| } |
| } |