test/serviceability/tmtools/jstat/utils/GcProvoker.java

rev 12309 : Rev 01

*** 1,7 ****
  /*
!  * Copyright (c) 2015, 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.
--- 1,7 ----
  /*
!  * Copyright (c) 2015, 2016, 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.
*** 20,55 ****
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  package utils;
  
  /**
!  * This is an interface used to provoke GC and perform other GC-related
   * procedures
   *
   */
! public interface GcProvoker {
  
      /**
!      * The default implementation
!      *
!      * @return the default GC provoker
       */
!     public static GcProvoker createGcProvoker() {
!         return new GcProvokerImpl();
      }
  
      /**
!      * This method provokes a GC
       */
!     public void provokeGc();
  
      /**
!      * Eats heap and metaspace Upon exit targetMemoryUsagePercent percents of
!      * heap and metaspace is have been eaten
       *
       * @param targetMemoryUsagePercent how many percent of heap and metaspace to
!      * eat
       */
!     public void eatMetaspaceAndHeap(float targetMemoryUsagePercent);
  
  }
--- 20,157 ----
   * 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.MemoryPoolMXBean;
+ import java.lang.management.MemoryUsage;
+ import java.util.ArrayList;
+ import java.util.List;
+ 
  /**
!  * This is an class used to provoke GC and perform other GC-related
   * procedures
   *
   */
! public class GcProvoker{
! 
!     // Uses fixed small objects to avoid Humongous objects allocation in G1
!     public static final int MEMORY_CHUNK = 2048;
!     public static final float ALLOCATION_TOLERANCE = 0.05f;
! 
!     public static List<Object> allocatedMetaspace;
!     public static List<Object> allocatedMemory;
!     
!     private final Runtime runtime;
! 
!     private List<Object> allocateHeap(float targetUsage) {
!         long maxMemory = runtime.maxMemory();
!         List<Object> list = new ArrayList<>();
!         long used = 0;
!         long target = (long) (maxMemory * targetUsage);
!         while (used < target) {
!             try {
!                 list.add(new byte[MEMORY_CHUNK]);
!                 used += MEMORY_CHUNK;
!             } catch (OutOfMemoryError e) {
!                 list = null;
!                 throw new RuntimeException("Unexpected OOME '" + e.getMessage() + "' while eating " + targetUsage + " of heap memory.");
!             }
!         }
!         return list;
!     }
!     
!     private List<Object> allocateAvailableHeap(float targetUsage) {
!         // Calculates size of free memory after allocation with small tolerance.
!         long minFreeMemory = (long) ((1.0 - (targetUsage + ALLOCATION_TOLERANCE)) * runtime.maxMemory());
!         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 eating " + targetUsage + " of heap memory.");
!             }
!         } while (runtime.freeMemory() > minFreeMemory);
!         return list;
!     }
  
      /**
!      * This method provokes a GC
       */
!     public void provokeGc() {
!         for (int i = 0; i < 3; i++) {
!             long edenSize = Pools.getEdenCommittedSize();
!             long heapSize = Pools.getHeapCommittedSize();
!             float targetPercent = ((float) edenSize) / (heapSize);
!             if ((targetPercent < 0) || (targetPercent > 1.0)) {
!                 throw new RuntimeException("Error in the percent calculation" + " (eden size: " + edenSize + ", heap size: " + heapSize + ", calculated eden percent: " + targetPercent + ")");
!             }
!             allocateHeap(targetPercent);
!             allocateHeap(targetPercent);
!             System.gc();
!         }
      }
  
      /**
!      * Allocates heap and metaspace upon exit not less than targetMemoryUsagePercent percents 
!      * of heap and metaspace have been consumed.
!      *
!      * @param targetMemoryUsagePercent how many percent of heap and metaspace to
!      * allocate
       */
! 
!     public void allocateMetaspaceAndHeap(float targetMemoryUsagePercent) {
!         // Metaspace should be filled before Java Heap to prevent unexpected OOME
!         // in the Java Heap while filling Metaspace
!         allocatedMetaspace = eatMetaspace(targetMemoryUsagePercent);
!         allocatedMemory = allocateHeap(targetMemoryUsagePercent);
!     }
      
      /**
!      * Allocates heap and metaspace upon exit targetMemoryUsagePercent percents 
!      * of heap and metaspace have been consumed.
       *
       * @param targetMemoryUsagePercent how many percent of heap and metaspace to
!      * allocate
       */
!     public void allocateAvailableMetaspaceAndHeap(float targetMemoryUsagePercent) {
!         // Metaspace should be filled before Java Heap to prevent unexpected OOME
!         // in the Java Heap while filling Metaspace
!         allocatedMetaspace = eatMetaspace(targetMemoryUsagePercent);
!         allocatedMemory = allocateAvailableHeap(targetMemoryUsagePercent);
!     }
! 
!     private List<Object> eatMetaspace(float targetUsage) {
!         List<Object> list = new ArrayList<>();
!         final String metaspacePoolName = "Metaspace";
!         MemoryPoolMXBean metaspacePool = null;
!         for (MemoryPoolMXBean pool : ManagementFactory.getMemoryPoolMXBeans()) {
!             if (pool.getName().contains(metaspacePoolName)) {
!                 metaspacePool = pool;
!                 break;
!             }
!         }
!         if (metaspacePool == null) {
!             throw new RuntimeException("MXBean for Metaspace pool wasn't found");
!         }
!         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;
!     }
! 
!     public GcProvoker() {
!         runtime = Runtime.getRuntime();
!     }
  
  }