| /* |
| * Copyright (c) 2014, 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 rtm; |
| |
| import java.util.concurrent.BrokenBarrierException; |
| import java.util.concurrent.CyclicBarrier; |
| |
| /** |
| * To force transactional execution abort due to memory conflict |
| * one thread should access memory region from transactional region |
| * while another thread should modify the same memory region. |
| * Since this scenario is based on the race condition between threads |
| * you should not expect some particular amount of aborts. |
| */ |
| class MemoryConflictProvoker extends AbortProvoker { |
| // Following field have to be static in order to avoid escape analysis. |
| @SuppressWarnings("UnsuedDeclaration") |
| private static int field = 0; |
| private static final int INNER_ITERATIONS = 10000; |
| private final CyclicBarrier barrier; |
| /** |
| * This thread will access and modify memory region |
| * from outside of the transaction. |
| */ |
| private final Runnable conflictingThread; |
| |
| public MemoryConflictProvoker() { |
| this(new Object()); |
| } |
| |
| public MemoryConflictProvoker(Object monitor) { |
| super(monitor); |
| barrier = new CyclicBarrier(2); |
| conflictingThread = () -> { |
| try { |
| barrier.await(); |
| } catch (Exception e) { |
| throw new RuntimeException(e); |
| } |
| for (int i = 0; i < MemoryConflictProvoker.INNER_ITERATIONS; i++) { |
| MemoryConflictProvoker.field++; |
| } |
| }; |
| } |
| |
| /** |
| * Accesses and modifies memory region from within the transaction. |
| */ |
| public void transactionalRegion() { |
| for (int i = 0; i < MemoryConflictProvoker.INNER_ITERATIONS; i++) { |
| synchronized(monitor) { |
| MemoryConflictProvoker.field--; |
| } |
| } |
| } |
| |
| @Override |
| public void forceAbort() { |
| try { |
| Thread t = new Thread(conflictingThread); |
| t.start(); |
| try { |
| barrier.await(); |
| } catch (InterruptedException | BrokenBarrierException e) { |
| throw new RuntimeException(e); |
| } |
| transactionalRegion(); |
| t.join(); |
| } catch (Exception e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| @Override |
| public String getMethodWithLockName() { |
| return this.getClass().getName() + "::transactionalRegion"; |
| } |
| } |