| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.hadoop.ha; |
| |
| import org.junit.Assert; |
| |
| /** |
| * A fake shared resource, for use in automatic failover testing. |
| * This simulates a real shared resource like a shared edit log. |
| * When the {@link DummyHAService} instances change state or get |
| * fenced, they notify the shared resource, which asserts that |
| * we never have two HA services who think they're holding the |
| * resource at the same time. |
| */ |
| public class DummySharedResource { |
| private DummyHAService holder = null; |
| private int violations = 0; |
| |
| public synchronized void take(DummyHAService newHolder) { |
| if (holder == null || holder == newHolder) { |
| holder = newHolder; |
| } else { |
| violations++; |
| throw new IllegalStateException("already held by: " + holder); |
| } |
| } |
| |
| public synchronized void release(DummyHAService oldHolder) { |
| if (holder == oldHolder) { |
| holder = null; |
| } |
| } |
| |
| public synchronized void assertNoViolations() { |
| Assert.assertEquals(0, violations); |
| } |
| } |