| /** |
| * 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.mapred; |
| |
| import java.util.HashSet; |
| import java.util.LinkedHashSet; |
| import java.util.HashMap; |
| import java.util.LinkedHashMap; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| // HashSet and HashMap do not guarantee that the oder of iteration is |
| // determinstic. We need the latter for the deterministic replay of |
| // simulations. These iterations are heavily used in the JobTracker, e.g. when |
| // looking for non-local map tasks. Not all HashSet and HashMap instances |
| // are iterated over, but to be safe and simple we replace all with |
| // LinkedHashSet and LinkedHashMap whose iteration order is deterministic. |
| |
| public privileged aspect DeterministicCollectionAspects { |
| |
| // Fortunately the Java runtime type of generic classes do not contain |
| // the generic parameter. We can catch all with a single base pattern using |
| // the erasure of the generic type. |
| |
| HashSet around() : call(HashSet.new()) { |
| return new LinkedHashSet(); |
| } |
| |
| HashMap around() : call(HashMap.new()) { |
| return new LinkedHashMap(); |
| } |
| |
| ConcurrentHashMap around() : call(ConcurrentHashMap.new()) { |
| return new FakeConcurrentHashMap(); |
| } |
| } |