Yuta HIGUCHI | e8f48d8 | 2016-08-24 20:27:48 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2016-present Open Networking Laboratory |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.onlab.util; |
| 17 | |
| 18 | import static com.google.common.base.Preconditions.checkArgument; |
| 19 | import static com.google.common.base.Preconditions.checkNotNull; |
| 20 | |
| 21 | import java.time.Duration; |
| 22 | import java.time.Instant; |
| 23 | import java.time.temporal.ChronoUnit; |
| 24 | import java.util.ArrayList; |
| 25 | import java.util.List; |
| 26 | import java.util.Objects; |
| 27 | import java.util.concurrent.AbstractExecutorService; |
| 28 | import java.util.concurrent.Callable; |
| 29 | import java.util.concurrent.ExecutorService; |
| 30 | import java.util.concurrent.Executors; |
| 31 | import java.util.concurrent.FutureTask; |
| 32 | import java.util.concurrent.ThreadFactory; |
| 33 | import java.util.concurrent.TimeUnit; |
| 34 | import java.util.function.Function; |
| 35 | import java.util.stream.Collectors; |
| 36 | |
| 37 | /** |
| 38 | * (Somewhat) predictable ExecutorService. |
| 39 | * <p> |
| 40 | * ExecutorService which behaves similar to the one created by |
| 41 | * {@link Executors#newFixedThreadPool(int, ThreadFactory)}, |
| 42 | * but assigns command to specific thread based on |
| 43 | * it's {@link PickyTask#hint()}, {@link Object#hashCode()}, or hint value explicitly |
| 44 | * specified when the command was passed to this {@link PredictableExecutor}. |
| 45 | */ |
| 46 | public class PredictableExecutor |
| 47 | extends AbstractExecutorService |
| 48 | implements ExecutorService { |
| 49 | |
| 50 | private final List<ExecutorService> backends; |
| 51 | |
| 52 | /** |
| 53 | * Creates {@link PredictableExecutor} instance. |
| 54 | * |
| 55 | * @param buckets number of buckets or 0 to match available processors |
| 56 | * @param threadFactory {@link ThreadFactory} to use to create threads |
| 57 | * @return {@link PredictableExecutor} |
| 58 | */ |
| 59 | public static PredictableExecutor newPredictableExecutor(int buckets, ThreadFactory threadFactory) { |
| 60 | return new PredictableExecutor(buckets, threadFactory); |
| 61 | } |
| 62 | |
| 63 | /** |
| 64 | * Creates {@link PredictableExecutor} instance. |
| 65 | * |
| 66 | * @param buckets number of buckets or 0 to match available processors |
| 67 | * @param threadFactory {@link ThreadFactory} to use to create threads |
| 68 | */ |
| 69 | public PredictableExecutor(int buckets, ThreadFactory threadFactory) { |
| 70 | checkArgument(buckets >= 0, "number of buckets must be non zero"); |
| 71 | checkNotNull(threadFactory); |
| 72 | if (buckets == 0) { |
| 73 | buckets = Runtime.getRuntime().availableProcessors(); |
| 74 | } |
| 75 | this.backends = new ArrayList<>(buckets); |
| 76 | |
| 77 | for (int i = 0; i < buckets; ++i) { |
| 78 | this.backends.add(backendExecutorService(threadFactory)); |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Creates {@link PredictableExecutor} instance with |
| 84 | * bucket size set to number of available processors. |
| 85 | * |
| 86 | * @param threadFactory {@link ThreadFactory} to use to create threads |
| 87 | */ |
| 88 | public PredictableExecutor(ThreadFactory threadFactory) { |
| 89 | this(0, threadFactory); |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * Creates a single thread {@link ExecutorService} to use in the backend. |
| 94 | * |
| 95 | * @param threadFactory {@link ThreadFactory} to use to create threads |
| 96 | * @return single thread {@link ExecutorService} |
| 97 | */ |
| 98 | protected ExecutorService backendExecutorService(ThreadFactory threadFactory) { |
| 99 | return Executors.newSingleThreadExecutor(threadFactory); |
| 100 | } |
| 101 | |
| 102 | |
| 103 | /** |
| 104 | * Executes given command at some time in the future. |
| 105 | * |
| 106 | * @param command the {@link Runnable} task |
| 107 | * @param hint value to pick thread to run on. |
| 108 | */ |
| 109 | public void execute(Runnable command, int hint) { |
| 110 | int index = Math.abs(hint) % backends.size(); |
| 111 | backends.get(index).execute(command); |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * Executes given command at some time in the future. |
| 116 | * |
| 117 | * @param command the {@link Runnable} task |
| 118 | * @param hintFunction Function to compute hint value |
| 119 | */ |
| 120 | public void execute(Runnable command, Function<Runnable, Integer> hintFunction) { |
| 121 | execute(command, hintFunction.apply(command)); |
| 122 | } |
| 123 | |
| 124 | |
| 125 | private static int hint(Runnable command) { |
| 126 | if (command instanceof PickyTask) { |
| 127 | return ((PickyTask) command).hint(); |
| 128 | } else { |
| 129 | return Objects.hashCode(command); |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | @Override |
| 134 | public void execute(Runnable command) { |
| 135 | execute(command, PredictableExecutor::hint); |
| 136 | } |
| 137 | |
| 138 | @Override |
| 139 | public void shutdown() { |
Sho SHIMIZU | 8ebb04a | 2016-10-06 15:58:29 -0700 | [diff] [blame] | 140 | backends.forEach(ExecutorService::shutdown); |
Yuta HIGUCHI | e8f48d8 | 2016-08-24 20:27:48 -0700 | [diff] [blame] | 141 | } |
| 142 | |
| 143 | @Override |
| 144 | public List<Runnable> shutdownNow() { |
| 145 | return backends.stream() |
| 146 | .map(ExecutorService::shutdownNow) |
| 147 | .flatMap(List::stream) |
| 148 | .collect(Collectors.toList()); |
| 149 | } |
| 150 | |
| 151 | @Override |
| 152 | public boolean isShutdown() { |
| 153 | return backends.stream().allMatch(ExecutorService::isShutdown); |
| 154 | } |
| 155 | |
| 156 | @Override |
| 157 | public boolean isTerminated() { |
| 158 | return backends.stream().allMatch(ExecutorService::isTerminated); |
| 159 | } |
| 160 | |
| 161 | /** |
| 162 | * {@inheritDoc} |
| 163 | * <p> |
| 164 | * Note: It'll try, but is not assured that the method will return by specified timeout. |
| 165 | */ |
| 166 | @Override |
| 167 | public boolean awaitTermination(long timeout, TimeUnit unit) |
| 168 | throws InterruptedException { |
| 169 | |
| 170 | final Duration timeoutD = Duration.of(unit.toMillis(timeout), ChronoUnit.MILLIS); |
| 171 | final Instant start = Instant.now(); |
| 172 | |
| 173 | return backends.parallelStream() |
| 174 | .filter(es -> !es.isTerminated()) |
| 175 | .map(es -> { |
| 176 | long timeoutMs = timeoutD.minus(Duration.between(Instant.now(), start)).toMillis(); |
| 177 | try { |
| 178 | return es.awaitTermination(timeoutMs, TimeUnit.MILLISECONDS); |
| 179 | } catch (InterruptedException e) { |
| 180 | Thread.currentThread().interrupt(); |
| 181 | return false; |
| 182 | } |
| 183 | }) |
| 184 | .allMatch(result -> result); |
| 185 | } |
| 186 | |
| 187 | @Override |
| 188 | protected <T> PickyFutureTask<T> newTaskFor(Callable<T> callable) { |
| 189 | return new PickyFutureTask<>(callable); |
| 190 | } |
| 191 | |
| 192 | @Override |
| 193 | protected <T> PickyFutureTask<T> newTaskFor(Runnable runnable, T value) { |
| 194 | return new PickyFutureTask<>(runnable, value); |
| 195 | } |
| 196 | |
| 197 | /** |
| 198 | * {@link Runnable} also implementing {@link PickyTask}. |
| 199 | */ |
| 200 | public static interface PickyRunnable extends PickyTask, Runnable { } |
| 201 | |
| 202 | /** |
| 203 | * {@link Callable} also implementing {@link PickyTask}. |
| 204 | * |
| 205 | * @param <T> result type |
| 206 | */ |
| 207 | public static interface PickyCallable<T> extends PickyTask, Callable<T> { } |
| 208 | |
| 209 | /** |
| 210 | * Wraps the given {@link Runnable} into {@link PickyRunnable} returning supplied hint. |
| 211 | * |
| 212 | * @param runnable {@link Runnable} |
| 213 | * @param hint hint value |
| 214 | * @return {@link PickyRunnable} |
| 215 | */ |
| 216 | public static PickyRunnable picky(Runnable runnable, int hint) { |
| 217 | return picky(runnable, (r) -> hint); |
| 218 | } |
| 219 | |
| 220 | /** |
| 221 | * Wraps the given {@link Runnable} into {@link PickyRunnable} returning supplied hint. |
| 222 | * |
| 223 | * @param runnable {@link Runnable} |
| 224 | * @param hint hint function |
| 225 | * @return {@link PickyRunnable} |
| 226 | */ |
| 227 | public static PickyRunnable picky(Runnable runnable, Function<Runnable, Integer> hint) { |
| 228 | checkNotNull(runnable); |
| 229 | checkNotNull(hint); |
| 230 | return new PickyRunnable() { |
| 231 | |
| 232 | @Override |
| 233 | public void run() { |
| 234 | runnable.run(); |
| 235 | } |
| 236 | |
| 237 | @Override |
| 238 | public int hint() { |
| 239 | return hint.apply(runnable); |
| 240 | } |
| 241 | }; |
| 242 | } |
| 243 | |
| 244 | /** |
| 245 | * Wraps the given {@link Callable} into {@link PickyCallable} returning supplied hint. |
| 246 | * |
| 247 | * @param callable {@link Callable} |
| 248 | * @param hint hint value |
Ray Milkey | ef79434 | 2016-11-09 16:20:29 -0800 | [diff] [blame] | 249 | * @param <T> entity type |
Yuta HIGUCHI | e8f48d8 | 2016-08-24 20:27:48 -0700 | [diff] [blame] | 250 | * @return {@link PickyCallable} |
| 251 | */ |
| 252 | public static <T> PickyCallable<T> picky(Callable<T> callable, int hint) { |
| 253 | return picky(callable, (c) -> hint); |
| 254 | } |
| 255 | |
| 256 | /** |
| 257 | * Wraps the given {@link Callable} into {@link PickyCallable} returning supplied hint. |
| 258 | * |
| 259 | * @param callable {@link Callable} |
| 260 | * @param hint hint function |
Ray Milkey | ef79434 | 2016-11-09 16:20:29 -0800 | [diff] [blame] | 261 | * @param <T> entity type |
Yuta HIGUCHI | e8f48d8 | 2016-08-24 20:27:48 -0700 | [diff] [blame] | 262 | * @return {@link PickyCallable} |
| 263 | */ |
| 264 | public static <T> PickyCallable<T> picky(Callable<T> callable, Function<Callable<T>, Integer> hint) { |
| 265 | checkNotNull(callable); |
| 266 | checkNotNull(hint); |
| 267 | return new PickyCallable<T>() { |
| 268 | |
| 269 | @Override |
| 270 | public T call() throws Exception { |
| 271 | return callable.call(); |
| 272 | } |
| 273 | |
| 274 | @Override |
| 275 | public int hint() { |
| 276 | return hint.apply(callable); |
| 277 | } |
| 278 | |
| 279 | }; |
| 280 | } |
| 281 | |
| 282 | /** |
| 283 | * Abstraction to give a task a way to express it's preference to run on |
| 284 | * certain thread. |
| 285 | */ |
| 286 | public static interface PickyTask { |
| 287 | |
| 288 | /** |
| 289 | * Returns hint for choosing which Thread to run this task on. |
| 290 | * |
| 291 | * @return hint value |
| 292 | */ |
| 293 | int hint(); |
| 294 | } |
| 295 | |
| 296 | /** |
| 297 | * A {@link FutureTask} implementing {@link PickyTask}. |
| 298 | * <p> |
| 299 | * Note: if the wrapped {@link Callable} or {@link Runnable} was an instance of |
| 300 | * {@link PickyTask}, it will use {@link PickyTask#hint()} value, if not use {@link Object#hashCode()}. |
| 301 | * |
| 302 | * @param <T> result type. |
| 303 | */ |
| 304 | public static class PickyFutureTask<T> |
| 305 | extends FutureTask<T> |
| 306 | implements PickyTask { |
| 307 | |
| 308 | private final Object runnableOrCallable; |
| 309 | |
| 310 | /** |
| 311 | * Same as {@link FutureTask#FutureTask(Runnable, Object)}. |
Ray Milkey | ef79434 | 2016-11-09 16:20:29 -0800 | [diff] [blame] | 312 | * |
| 313 | * @param runnable work to do |
| 314 | * @param value result |
Yuta HIGUCHI | e8f48d8 | 2016-08-24 20:27:48 -0700 | [diff] [blame] | 315 | */ |
| 316 | public PickyFutureTask(Runnable runnable, T value) { |
| 317 | super(runnable, value); |
| 318 | runnableOrCallable = checkNotNull(runnable); |
| 319 | } |
| 320 | |
| 321 | /** |
| 322 | * Same as {@link FutureTask#FutureTask(Callable)}. |
Ray Milkey | ef79434 | 2016-11-09 16:20:29 -0800 | [diff] [blame] | 323 | * |
| 324 | * @param callable work to be done |
Yuta HIGUCHI | e8f48d8 | 2016-08-24 20:27:48 -0700 | [diff] [blame] | 325 | */ |
| 326 | public PickyFutureTask(Callable<T> callable) { |
| 327 | super(callable); |
| 328 | runnableOrCallable = checkNotNull(callable); |
| 329 | } |
| 330 | |
| 331 | @Override |
| 332 | public int hint() { |
| 333 | if (runnableOrCallable instanceof PickyTask) { |
| 334 | return ((PickyTask) runnableOrCallable).hint(); |
| 335 | } else { |
| 336 | return runnableOrCallable.hashCode(); |
| 337 | } |
| 338 | } |
| 339 | } |
| 340 | } |