1 /* 2 * Copyright (c) 2002, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /* 25 * @test 26 * @key stress gc 27 * 28 * @summary converted from VM Testbase gc/gctests/MTLinkedListGC. 29 * VM Testbase keywords: [gc, stress, nonconcurrent] 30 * VM Testbase readme: 31 * In this test 1000 threads contribute in the formation 32 * of 1 Meg circular Linked list. Insertion into the linked list 33 * is sequential. Once formed, the linked list is converted to 34 * garbage and the process repeated 50 times. The test fails 35 * if an OutofMemoryException is thrown and passes otherwise. 36 * 37 * @library /vmTestbase 38 * /test/lib 39 * @run driver jdk.test.lib.FileInstaller . . 40 * @run main/othervm gc.gctests.MTLinkedListGC.MTLinkedListGC 41 */ 42 43 package gc.gctests.MTLinkedListGC; 44 45 import java.util.Vector; 46 import nsk.share.TestFailure; 47 48 class CircularLinkedList { 49 synchronized void addElement(String info) { 50 node newnode; 51 int elementCount ; // Number of nodes in LinkedList 52 elementCount = elementCount(); 53 // Do not allow the linked list to grow to more 54 // than 100000 nodes 55 if (elementCount >= MAXNODES) 56 return; 57 newnode = new node(info); 58 if (Root == null) { 59 Root = newnode; 60 Root.next = Root; 61 Root.prev = Root; 62 } 63 else { 64 newnode.next = Root.next; 65 Root.next.prev = newnode; 66 Root.next = newnode; 67 newnode.prev = Root; 68 } 69 } 70 private synchronized int elementCount() { 71 node p; 72 int count; 73 if (Root == null) 74 return 0; 75 p = Root; 76 count = 0; 77 do { 78 p = p.prev; 79 count++; 80 } while(p != Root); 81 return count; 82 } 83 private node Root; 84 private final int MAXNODES = 100000; 85 } 86 87 class LinkedListGrower extends Thread { 88 LinkedListGrower(int ThreadNumber) { 89 setName("Thread-" + ThreadNumber); 90 } 91 92 public void run() { 93 LinkedListHolder.getCircularLinkedList().addElement(getName()); 94 } 95 } 96 97 class LinkedListHolder { 98 private static CircularLinkedList cl = new CircularLinkedList(); 99 static CircularLinkedList getCircularLinkedList() { return cl; } 100 static void getNewList() { cl = new CircularLinkedList(); } 101 } 102 103 public class MTLinkedListGC { 104 public static void main(String args[]) { 105 int memory_reserve[] = new int [1000]; 106 Thread ThreadsArray[] = new LinkedListGrower[1000]; 107 int count; 108 // for(int i = 0; i < ThreadsArray.length; i++ ) 109 // ThreadsArray[i] = new LinkedListGrower(i); 110 count = 0; 111 try { 112 while(count < 50 ){ 113 for(int i = 0; i < ThreadsArray.length; i++ ) 114 ThreadsArray[i] = new LinkedListGrower(i); 115 for(int i = 0 ; i < ThreadsArray.length ; i++) 116 ThreadsArray[i].start(); 117 try { 118 for(int i =0 ; i < ThreadsArray.length ; i++) 119 ThreadsArray[i].join(); 120 } catch(Exception e) { } 121 //turn the old linked list into garbage 122 LinkedListHolder.getNewList(); 123 System.out.println("Finished iteration " + count); 124 count ++; 125 } 126 } catch (OutOfMemoryError e) { 127 memory_reserve = null; 128 System.gc(); 129 throw new TestFailure("Test Failed at " + count +"th iteration."); 130 } 131 System.out.println("Test Passed"); 132 } 133 }