Umesh Krishnaswamy | 345ee99 | 2012-12-13 20:29:48 -0800 | [diff] [blame] | 1 | /** |
| 2 | * Copyright 2011, Big Switch Networks, Inc. |
| 3 | * Originally created by David Erickson, Stanford University |
| 4 | * |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| 6 | * not use this file except in compliance with the License. You may obtain |
| 7 | * a copy of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| 13 | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| 14 | * License for the specific language governing permissions and limitations |
| 15 | * under the License. |
| 16 | **/ |
| 17 | |
| 18 | package net.floodlightcontroller.storage; |
| 19 | |
| 20 | import java.util.ArrayList; |
| 21 | import java.util.Collection; |
| 22 | import java.util.List; |
| 23 | import java.util.concurrent.ExecutorService; |
| 24 | import java.util.concurrent.Callable; |
| 25 | import java.util.concurrent.ExecutionException; |
| 26 | import java.util.concurrent.Future; |
| 27 | import java.util.concurrent.TimeUnit; |
| 28 | import java.util.concurrent.TimeoutException; |
| 29 | |
| 30 | public class SynchronousExecutorService implements ExecutorService { |
| 31 | |
| 32 | class SynchronousFuture<T> implements Future<T> { |
| 33 | |
| 34 | T result; |
| 35 | Exception exc; |
| 36 | |
| 37 | public SynchronousFuture() { |
| 38 | } |
| 39 | |
| 40 | public SynchronousFuture(T result) { |
| 41 | this.result = result; |
| 42 | } |
| 43 | |
| 44 | public SynchronousFuture(Exception exc) { |
| 45 | this.exc = exc; |
| 46 | } |
| 47 | |
| 48 | @Override |
| 49 | public boolean cancel(boolean mayInterruptIfRunning) { |
| 50 | return false; |
| 51 | } |
| 52 | |
| 53 | @Override |
| 54 | public boolean isCancelled() { |
| 55 | return false; |
| 56 | } |
| 57 | |
| 58 | @Override |
| 59 | public boolean isDone() { |
| 60 | return true; |
| 61 | } |
| 62 | |
| 63 | @Override |
| 64 | public T get() throws InterruptedException, ExecutionException { |
| 65 | if (exc != null) |
| 66 | throw new ExecutionException(exc); |
| 67 | return result; |
| 68 | } |
| 69 | |
| 70 | @Override |
| 71 | public T get(long timeout, TimeUnit unit) throws InterruptedException, |
| 72 | ExecutionException, TimeoutException { |
| 73 | return get(); |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | @Override |
| 78 | public void shutdown() { |
| 79 | } |
| 80 | |
| 81 | @Override |
| 82 | public List<Runnable> shutdownNow() { |
| 83 | return null; |
| 84 | } |
| 85 | |
| 86 | @Override |
| 87 | public boolean isShutdown() { |
| 88 | return false; |
| 89 | } |
| 90 | |
| 91 | @Override |
| 92 | public boolean isTerminated() { |
| 93 | return false; |
| 94 | } |
| 95 | |
| 96 | @Override |
| 97 | public boolean awaitTermination(long timeout, TimeUnit unit) |
| 98 | throws InterruptedException { |
| 99 | return false; |
| 100 | } |
| 101 | |
| 102 | @Override |
| 103 | public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks) |
| 104 | throws InterruptedException { |
| 105 | List<Future<T>> l = new ArrayList<Future<T>>(); |
| 106 | for (Callable<T> task : tasks) { |
| 107 | Future<T> future = submit(task); |
| 108 | l.add(future); |
| 109 | } |
| 110 | return l; |
| 111 | } |
| 112 | |
| 113 | @Override |
| 114 | public <T> List<Future<T>> invokeAll( |
| 115 | Collection<? extends Callable<T>> tasks, long timeout, TimeUnit units) |
| 116 | throws InterruptedException { |
| 117 | return invokeAll(tasks); |
| 118 | } |
| 119 | |
| 120 | @Override |
| 121 | public <T> T invokeAny(Collection<? extends Callable<T>> tasks) |
| 122 | throws InterruptedException, ExecutionException { |
| 123 | for (Callable<T> task : tasks) { |
| 124 | try { |
| 125 | task.call(); |
| 126 | } catch (Exception e) { |
| 127 | |
| 128 | } |
| 129 | } |
| 130 | throw new ExecutionException(new Exception("no task completed successfully")); |
| 131 | } |
| 132 | |
| 133 | @Override |
| 134 | public <T> T invokeAny(Collection<? extends Callable<T>> tasks, long timeout, |
| 135 | TimeUnit units) throws InterruptedException, ExecutionException, |
| 136 | TimeoutException { |
| 137 | return invokeAny(tasks); |
| 138 | } |
| 139 | |
| 140 | @Override |
| 141 | public <T> Future<T> submit(Callable<T> callable) { |
| 142 | try { |
| 143 | T result = callable.call(); |
| 144 | return new SynchronousFuture<T>(result); |
| 145 | } |
| 146 | catch (Exception exc) { |
| 147 | return new SynchronousFuture<T>(exc); |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | @Override |
| 152 | public Future<?> submit(Runnable runnable) { |
| 153 | try { |
| 154 | runnable.run(); |
| 155 | return new SynchronousFuture<Void>(); |
| 156 | } |
| 157 | catch (Exception exc) { |
| 158 | return new SynchronousFuture<Void>(exc); |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | @Override |
| 163 | public <T> Future<T> submit(Runnable runnable, T result) { |
| 164 | try { |
| 165 | runnable.run(); |
| 166 | return new SynchronousFuture<T>(result); |
| 167 | } |
| 168 | catch (Exception exc) { |
| 169 | return new SynchronousFuture<T>(exc); |
| 170 | } |
| 171 | } |
| 172 | |
| 173 | @Override |
| 174 | public void execute(Runnable command) { |
| 175 | command.run(); |
| 176 | } |
| 177 | } |