1/* 2 * Copyright (c) 2014, 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 24package compiler.testlibrary.rtm; 25 26import java.util.concurrent.BrokenBarrierException; 27import java.util.concurrent.CyclicBarrier; 28 29/** 30 * To force transactional execution abort due to memory conflict 31 * one thread should access memory region from transactional region 32 * while another thread should modify the same memory region. 33 * Since this scenario is based on the race condition between threads 34 * you should not expect some particular amount of aborts. 35 */ 36class MemoryConflictProvoker extends AbortProvoker { 37 // Following field have to be static in order to avoid escape analysis. 38 @SuppressWarnings("UnsuedDeclaration") 39 private static int field = 0; 40 private static final int INNER_ITERATIONS = 10000; 41 private final CyclicBarrier barrier; 42 /** 43 * This thread will access and modify memory region 44 * from outside of the transaction. 45 */ 46 private final Runnable conflictingThread; 47 48 public MemoryConflictProvoker() { 49 this(new Object()); 50 } 51 52 public MemoryConflictProvoker(Object monitor) { 53 super(monitor); 54 barrier = new CyclicBarrier(2); 55 conflictingThread = () -> { 56 try { 57 barrier.await(); 58 } catch (Exception e) { 59 throw new RuntimeException(e); 60 } 61 for (int i = 0; i < MemoryConflictProvoker.INNER_ITERATIONS; i++) { 62 MemoryConflictProvoker.field++; 63 } 64 }; 65 } 66 67 /** 68 * Accesses and modifies memory region from within the transaction. 69 */ 70 public void transactionalRegion() { 71 for (int i = 0; i < MemoryConflictProvoker.INNER_ITERATIONS; i++) { 72 synchronized(monitor) { 73 MemoryConflictProvoker.field--; 74 } 75 } 76 } 77 78 @Override 79 public void forceAbort() { 80 try { 81 Thread t = new Thread(conflictingThread); 82 t.start(); 83 try { 84 barrier.await(); 85 } catch (InterruptedException | BrokenBarrierException e) { 86 throw new RuntimeException(e); 87 } 88 transactionalRegion(); 89 t.join(); 90 } catch (Exception e) { 91 throw new RuntimeException(e); 92 } 93 } 94 95 @Override 96 public String getMethodWithLockName() { 97 return this.getClass().getName() + "::transactionalRegion"; 98 } 99} 100