1 /* 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. Oracle designates this 7 * particular file as subject to the "Classpath" exception as provided 8 * by Oracle in the LICENSE file that accompanied this code. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 */ 24 25 /* 26 * This file is available under and governed by the GNU General Public 27 * License version 2 only, as published by the Free Software Foundation. 28 * However, the following notice accompanied the original version of this 29 * file: 30 * 31 * Written by Doug Lea with assistance from members of JCP JSR-166 32 * Expert Group and released to the public domain, as explained at 33 * http://creativecommons.org/licenses/publicdomain 34 */ 35 36 package java.util.concurrent; 37 import java.util.*; 38 import java.util.concurrent.atomic.AtomicInteger; 39 import java.security.AccessControlContext; 40 import java.security.AccessController; 41 import java.security.PrivilegedAction; 42 import java.security.PrivilegedExceptionAction; 43 import java.security.PrivilegedActionException; 44 import java.security.AccessControlException; 45 import sun.security.util.SecurityConstants; 46 47 /** 48 * Factory and utility methods for {@link Executor}, {@link 49 * ExecutorService}, {@link ScheduledExecutorService}, {@link 50 * ThreadFactory}, and {@link Callable} classes defined in this 51 * package. This class supports the following kinds of methods: 52 * 53 * <ul> 54 * <li> Methods that create and return an {@link ExecutorService} 55 * set up with commonly useful configuration settings. 56 * <li> Methods that create and return a {@link ScheduledExecutorService} 57 * set up with commonly useful configuration settings. 58 * <li> Methods that create and return a "wrapped" ExecutorService, that 59 * disables reconfiguration by making implementation-specific methods 60 * inaccessible. 61 * <li> Methods that create and return a {@link ThreadFactory} 62 * that sets newly created threads to a known state. 63 * <li> Methods that create and return a {@link Callable} 64 * out of other closure-like forms, so they can be used 65 * in execution methods requiring <tt>Callable</tt>. 66 * </ul> 67 * 68 * @since 1.5 69 * @author Doug Lea 70 */ 71 public class Executors { 72 73 /** 74 * Creates a thread pool that reuses a fixed number of threads 75 * operating off a shared unbounded queue. At any point, at most 76 * <tt>nThreads</tt> threads will be active processing tasks. 77 * If additional tasks are submitted when all threads are active, 78 * they will wait in the queue until a thread is available. 79 * If any thread terminates due to a failure during execution 80 * prior to shutdown, a new one will take its place if needed to 81 * execute subsequent tasks. The threads in the pool will exist 82 * until it is explicitly {@link ExecutorService#shutdown shutdown}. 83 * 84 * @param nThreads the number of threads in the pool 85 * @return the newly created thread pool 86 * @throws IllegalArgumentException if <tt>nThreads <= 0</tt> 87 */ 88 public static ExecutorService newFixedThreadPool(int nThreads) { 89 return new ThreadPoolExecutor(nThreads, nThreads, 90 0L, TimeUnit.MILLISECONDS, 91 new LinkedBlockingQueue<Runnable>()); 92 } 93 94 /** 95 * Creates a thread pool that reuses a fixed number of threads 96 * operating off a shared unbounded queue, using the provided 97 * ThreadFactory to create new threads when needed. At any point, 98 * at most <tt>nThreads</tt> threads will be active processing 99 * tasks. If additional tasks are submitted when all threads are 100 * active, they will wait in the queue until a thread is 101 * available. If any thread terminates due to a failure during 102 * execution prior to shutdown, a new one will take its place if 103 * needed to execute subsequent tasks. The threads in the pool will 104 * exist until it is explicitly {@link ExecutorService#shutdown 105 * shutdown}. 106 * 107 * @param nThreads the number of threads in the pool 108 * @param threadFactory the factory to use when creating new threads 109 * @return the newly created thread pool 110 * @throws NullPointerException if threadFactory is null 111 * @throws IllegalArgumentException if <tt>nThreads <= 0</tt> 112 */ 113 public static ExecutorService newFixedThreadPool(int nThreads, ThreadFactory threadFactory) { 114 return new ThreadPoolExecutor(nThreads, nThreads, 115 0L, TimeUnit.MILLISECONDS, 116 new LinkedBlockingQueue<Runnable>(), 117 threadFactory); 118 } 119 120 /** 121 * Creates an Executor that uses a single worker thread operating 122 * off an unbounded queue. (Note however that if this single 123 * thread terminates due to a failure during execution prior to 124 * shutdown, a new one will take its place if needed to execute 125 * subsequent tasks.) Tasks are guaranteed to execute 126 * sequentially, and no more than one task will be active at any 127 * given time. Unlike the otherwise equivalent 128 * <tt>newFixedThreadPool(1)</tt> the returned executor is 129 * guaranteed not to be reconfigurable to use additional threads. 130 * 131 * @return the newly created single-threaded Executor 132 */ 133 public static ExecutorService newSingleThreadExecutor() { 134 return new FinalizableDelegatedExecutorService 135 (new ThreadPoolExecutor(1, 1, 136 0L, TimeUnit.MILLISECONDS, 137 new LinkedBlockingQueue<Runnable>())); 138 } 139 140 /** 141 * Creates an Executor that uses a single worker thread operating 142 * off an unbounded queue, and uses the provided ThreadFactory to 143 * create a new thread when needed. Unlike the otherwise 144 * equivalent <tt>newFixedThreadPool(1, threadFactory)</tt> the 145 * returned executor is guaranteed not to be reconfigurable to use 146 * additional threads. 147 * 148 * @param threadFactory the factory to use when creating new 149 * threads 150 * 151 * @return the newly created single-threaded Executor 152 * @throws NullPointerException if threadFactory is null 153 */ 154 public static ExecutorService newSingleThreadExecutor(ThreadFactory threadFactory) { 155 return new FinalizableDelegatedExecutorService 156 (new ThreadPoolExecutor(1, 1, 157 0L, TimeUnit.MILLISECONDS, 158 new LinkedBlockingQueue<Runnable>(), 159 threadFactory)); 160 } 161 162 /** 163 * Creates a thread pool that creates new threads as needed, but 164 * will reuse previously constructed threads when they are 165 * available. These pools will typically improve the performance 166 * of programs that execute many short-lived asynchronous tasks. 167 * Calls to <tt>execute</tt> will reuse previously constructed 168 * threads if available. If no existing thread is available, a new 169 * thread will be created and added to the pool. Threads that have 170 * not been used for sixty seconds are terminated and removed from 171 * the cache. Thus, a pool that remains idle for long enough will 172 * not consume any resources. Note that pools with similar 173 * properties but different details (for example, timeout parameters) 174 * may be created using {@link ThreadPoolExecutor} constructors. 175 * 176 * @return the newly created thread pool 177 */ 178 public static ExecutorService newCachedThreadPool() { 179 return new ThreadPoolExecutor(0, Integer.MAX_VALUE, 180 60L, TimeUnit.SECONDS, 181 new SynchronousQueue<Runnable>()); 182 } 183 184 /** 185 * Creates a thread pool that creates new threads as needed, but 186 * will reuse previously constructed threads when they are 187 * available, and uses the provided 188 * ThreadFactory to create new threads when needed. 189 * @param threadFactory the factory to use when creating new threads 190 * @return the newly created thread pool 191 * @throws NullPointerException if threadFactory is null 192 */ 193 public static ExecutorService newCachedThreadPool(ThreadFactory threadFactory) { 194 return new ThreadPoolExecutor(0, Integer.MAX_VALUE, 195 60L, TimeUnit.SECONDS, 196 new SynchronousQueue<Runnable>(), 197 threadFactory); 198 } 199 200 /** 201 * Creates a single-threaded executor that can schedule commands 202 * to run after a given delay, or to execute periodically. 203 * (Note however that if this single 204 * thread terminates due to a failure during execution prior to 205 * shutdown, a new one will take its place if needed to execute 206 * subsequent tasks.) Tasks are guaranteed to execute 207 * sequentially, and no more than one task will be active at any 208 * given time. Unlike the otherwise equivalent 209 * <tt>newScheduledThreadPool(1)</tt> the returned executor is 210 * guaranteed not to be reconfigurable to use additional threads. 211 * @return the newly created scheduled executor 212 */ 213 public static ScheduledExecutorService newSingleThreadScheduledExecutor() { 214 return new DelegatedScheduledExecutorService 215 (new ScheduledThreadPoolExecutor(1)); 216 } 217 218 /** 219 * Creates a single-threaded executor that can schedule commands 220 * to run after a given delay, or to execute periodically. (Note 221 * however that if this single thread terminates due to a failure 222 * during execution prior to shutdown, a new one will take its 223 * place if needed to execute subsequent tasks.) Tasks are 224 * guaranteed to execute sequentially, and no more than one task 225 * will be active at any given time. Unlike the otherwise 226 * equivalent <tt>newScheduledThreadPool(1, threadFactory)</tt> 227 * the returned executor is guaranteed not to be reconfigurable to 228 * use additional threads. 229 * @param threadFactory the factory to use when creating new 230 * threads 231 * @return a newly created scheduled executor 232 * @throws NullPointerException if threadFactory is null 233 */ 234 public static ScheduledExecutorService newSingleThreadScheduledExecutor(ThreadFactory threadFactory) { 235 return new DelegatedScheduledExecutorService 236 (new ScheduledThreadPoolExecutor(1, threadFactory)); 237 } 238 239 /** 240 * Creates a thread pool that can schedule commands to run after a 241 * given delay, or to execute periodically. 242 * @param corePoolSize the number of threads to keep in the pool, 243 * even if they are idle. 244 * @return a newly created scheduled thread pool 245 * @throws IllegalArgumentException if <tt>corePoolSize < 0</tt> 246 */ 247 public static ScheduledExecutorService newScheduledThreadPool(int corePoolSize) { 248 return new ScheduledThreadPoolExecutor(corePoolSize); 249 } 250 251 /** 252 * Creates a thread pool that can schedule commands to run after a 253 * given delay, or to execute periodically. 254 * @param corePoolSize the number of threads to keep in the pool, 255 * even if they are idle. 256 * @param threadFactory the factory to use when the executor 257 * creates a new thread. 258 * @return a newly created scheduled thread pool 259 * @throws IllegalArgumentException if <tt>corePoolSize < 0</tt> 260 * @throws NullPointerException if threadFactory is null 261 */ 262 public static ScheduledExecutorService newScheduledThreadPool( 263 int corePoolSize, ThreadFactory threadFactory) { 264 return new ScheduledThreadPoolExecutor(corePoolSize, threadFactory); 265 } 266 267 268 /** 269 * Returns an object that delegates all defined {@link 270 * ExecutorService} methods to the given executor, but not any 271 * other methods that might otherwise be accessible using 272 * casts. This provides a way to safely "freeze" configuration and 273 * disallow tuning of a given concrete implementation. 274 * @param executor the underlying implementation 275 * @return an <tt>ExecutorService</tt> instance 276 * @throws NullPointerException if executor null 277 */ 278 public static ExecutorService unconfigurableExecutorService(ExecutorService executor) { 279 if (executor == null) 280 throw new NullPointerException(); 281 return new DelegatedExecutorService(executor); 282 } 283 284 /** 285 * Returns an object that delegates all defined {@link 286 * ScheduledExecutorService} methods to the given executor, but 287 * not any other methods that might otherwise be accessible using 288 * casts. This provides a way to safely "freeze" configuration and 289 * disallow tuning of a given concrete implementation. 290 * @param executor the underlying implementation 291 * @return a <tt>ScheduledExecutorService</tt> instance 292 * @throws NullPointerException if executor null 293 */ 294 public static ScheduledExecutorService unconfigurableScheduledExecutorService(ScheduledExecutorService executor) { 295 if (executor == null) 296 throw new NullPointerException(); 297 return new DelegatedScheduledExecutorService(executor); 298 } 299 300 /** 301 * Returns a default thread factory used to create new threads. 302 * This factory creates all new threads used by an Executor in the 303 * same {@link ThreadGroup}. If there is a {@link 304 * java.lang.SecurityManager}, it uses the group of {@link 305 * System#getSecurityManager}, else the group of the thread 306 * invoking this <tt>defaultThreadFactory</tt> method. Each new 307 * thread is created as a non-daemon thread with priority set to 308 * the smaller of <tt>Thread.NORM_PRIORITY</tt> and the maximum 309 * priority permitted in the thread group. New threads have names 310 * accessible via {@link Thread#getName} of 311 * <em>pool-N-thread-M</em>, where <em>N</em> is the sequence 312 * number of this factory, and <em>M</em> is the sequence number 313 * of the thread created by this factory. 314 * @return a thread factory 315 */ 316 public static ThreadFactory defaultThreadFactory() { 317 return new DefaultThreadFactory(); 318 } 319 320 /** 321 * Returns a thread factory used to create new threads that 322 * have the same permissions as the current thread. 323 * This factory creates threads with the same settings as {@link 324 * Executors#defaultThreadFactory}, additionally setting the 325 * AccessControlContext and contextClassLoader of new threads to 326 * be the same as the thread invoking this 327 * <tt>privilegedThreadFactory</tt> method. A new 328 * <tt>privilegedThreadFactory</tt> can be created within an 329 * {@link AccessController#doPrivileged} action setting the 330 * current thread's access control context to create threads with 331 * the selected permission settings holding within that action. 332 * 333 * <p> Note that while tasks running within such threads will have 334 * the same access control and class loader settings as the 335 * current thread, they need not have the same {@link 336 * java.lang.ThreadLocal} or {@link 337 * java.lang.InheritableThreadLocal} values. If necessary, 338 * particular values of thread locals can be set or reset before 339 * any task runs in {@link ThreadPoolExecutor} subclasses using 340 * {@link ThreadPoolExecutor#beforeExecute}. Also, if it is 341 * necessary to initialize worker threads to have the same 342 * InheritableThreadLocal settings as some other designated 343 * thread, you can create a custom ThreadFactory in which that 344 * thread waits for and services requests to create others that 345 * will inherit its values. 346 * 347 * @return a thread factory 348 * @throws AccessControlException if the current access control 349 * context does not have permission to both get and set context 350 * class loader. 351 */ 352 public static ThreadFactory privilegedThreadFactory() { 353 return new PrivilegedThreadFactory(); 354 } 355 356 /** 357 * Returns a {@link Callable} object that, when 358 * called, runs the given task and returns the given result. This 359 * can be useful when applying methods requiring a 360 * <tt>Callable</tt> to an otherwise resultless action. 361 * @param task the task to run 362 * @param result the result to return 363 * @return a callable object 364 * @throws NullPointerException if task null 365 */ 366 public static <T> Callable<T> callable(Runnable task, T result) { 367 if (task == null) 368 throw new NullPointerException(); 369 return new RunnableAdapter<T>(task, result); 370 } 371 372 /** 373 * Returns a {@link Callable} object that, when 374 * called, runs the given task and returns <tt>null</tt>. 375 * @param task the task to run 376 * @return a callable object 377 * @throws NullPointerException if task null 378 */ 379 public static Callable<Object> callable(Runnable task) { 380 if (task == null) 381 throw new NullPointerException(); 382 return new RunnableAdapter<Object>(task, null); 383 } 384 385 /** 386 * Returns a {@link Callable} object that, when 387 * called, runs the given privileged action and returns its result. 388 * @param action the privileged action to run 389 * @return a callable object 390 * @throws NullPointerException if action null 391 */ 392 public static Callable<Object> callable(final PrivilegedAction<?> action) { 393 if (action == null) 394 throw new NullPointerException(); 395 return new Callable<Object>() { 396 public Object call() { return action.run(); }}; 397 } 398 399 /** 400 * Returns a {@link Callable} object that, when 401 * called, runs the given privileged exception action and returns 402 * its result. 403 * @param action the privileged exception action to run 404 * @return a callable object 405 * @throws NullPointerException if action null 406 */ 407 public static Callable<Object> callable(final PrivilegedExceptionAction<?> action) { 408 if (action == null) 409 throw new NullPointerException(); 410 return new Callable<Object>() { 411 public Object call() throws Exception { return action.run(); }}; 412 } 413 414 /** 415 * Returns a {@link Callable} object that will, when 416 * called, execute the given <tt>callable</tt> under the current 417 * access control context. This method should normally be 418 * invoked within an {@link AccessController#doPrivileged} action 419 * to create callables that will, if possible, execute under the 420 * selected permission settings holding within that action; or if 421 * not possible, throw an associated {@link 422 * AccessControlException}. 423 * @param callable the underlying task 424 * @return a callable object 425 * @throws NullPointerException if callable null 426 * 427 */ 428 public static <T> Callable<T> privilegedCallable(Callable<T> callable) { 429 if (callable == null) 430 throw new NullPointerException(); 431 return new PrivilegedCallable<T>(callable); 432 } 433 434 /** 435 * Returns a {@link Callable} object that will, when 436 * called, execute the given <tt>callable</tt> under the current 437 * access control context, with the current context class loader 438 * as the context class loader. This method should normally be 439 * invoked within an {@link AccessController#doPrivileged} action 440 * to create callables that will, if possible, execute under the 441 * selected permission settings holding within that action; or if 442 * not possible, throw an associated {@link 443 * AccessControlException}. 444 * @param callable the underlying task 445 * 446 * @return a callable object 447 * @throws NullPointerException if callable null 448 * @throws AccessControlException if the current access control 449 * context does not have permission to both set and get context 450 * class loader. 451 */ 452 public static <T> Callable<T> privilegedCallableUsingCurrentClassLoader(Callable<T> callable) { 453 if (callable == null) 454 throw new NullPointerException(); 455 return new PrivilegedCallableUsingCurrentClassLoader<T>(callable); 456 } 457 458 // Non-public classes supporting the public methods 459 460 /** 461 * A callable that runs given task and returns given result 462 */ 463 static final class RunnableAdapter<T> implements Callable<T> { 464 final Runnable task; 465 final T result; 466 RunnableAdapter(Runnable task, T result) { 467 this.task = task; 468 this.result = result; 469 } 470 public T call() { 471 task.run(); 472 return result; 473 } 474 } 475 476 /** 477 * A callable that runs under established access control settings 478 */ 479 static final class PrivilegedCallable<T> implements Callable<T> { 480 private final Callable<T> task; 481 private final AccessControlContext acc; 482 483 PrivilegedCallable(Callable<T> task) { 484 this.task = task; 485 this.acc = AccessController.getContext(); 486 } 487 488 public T call() throws Exception { 489 try { 490 return AccessController.doPrivileged( 491 new PrivilegedExceptionAction<T>() { 492 public T run() throws Exception { 493 return task.call(); 494 } 495 }, acc); 496 } catch (PrivilegedActionException e) { 497 throw e.getException(); 498 } 499 } 500 } 501 502 /** 503 * A callable that runs under established access control settings and 504 * current ClassLoader 505 */ 506 static final class PrivilegedCallableUsingCurrentClassLoader<T> implements Callable<T> { 507 private final Callable<T> task; 508 private final AccessControlContext acc; 509 private final ClassLoader ccl; 510 511 PrivilegedCallableUsingCurrentClassLoader(Callable<T> task) { 512 SecurityManager sm = System.getSecurityManager(); 513 if (sm != null) { 514 // Calls to getContextClassLoader from this class 515 // never trigger a security check, but we check 516 // whether our callers have this permission anyways. 517 sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION); 518 519 // Whether setContextClassLoader turns out to be necessary 520 // or not, we fail fast if permission is not available. 521 sm.checkPermission(new RuntimePermission("setContextClassLoader")); 522 } 523 this.task = task; 524 this.acc = AccessController.getContext(); 525 this.ccl = Thread.currentThread().getContextClassLoader(); 526 } 527 528 public T call() throws Exception { 529 try { 530 return AccessController.doPrivileged( 531 new PrivilegedExceptionAction<T>() { 532 public T run() throws Exception { 533 ClassLoader savedcl = null; 534 Thread t = Thread.currentThread(); 535 try { 536 ClassLoader cl = t.getContextClassLoader(); 537 if (ccl != cl) { 538 t.setContextClassLoader(ccl); 539 savedcl = cl; 540 } 541 return task.call(); 542 } finally { 543 if (savedcl != null) 544 t.setContextClassLoader(savedcl); 545 } 546 } 547 }, acc); 548 } catch (PrivilegedActionException e) { 549 throw e.getException(); 550 } 551 } 552 } 553 554 /** 555 * The default thread factory 556 */ 557 static class DefaultThreadFactory implements ThreadFactory { 558 private static final AtomicInteger poolNumber = new AtomicInteger(1); 559 private final ThreadGroup group; 560 private final AtomicInteger threadNumber = new AtomicInteger(1); 561 private final String namePrefix; 562 563 DefaultThreadFactory() { 564 SecurityManager s = System.getSecurityManager(); 565 group = (s != null)? s.getThreadGroup() : 566 Thread.currentThread().getThreadGroup(); 567 namePrefix = "pool-" + 568 poolNumber.getAndIncrement() + 569 "-thread-"; 570 } 571 572 public Thread newThread(Runnable r) { 573 Thread t = new Thread(group, r, 574 namePrefix + threadNumber.getAndIncrement(), 575 0); 576 if (t.isDaemon()) 577 t.setDaemon(false); 578 if (t.getPriority() != Thread.NORM_PRIORITY) 579 t.setPriority(Thread.NORM_PRIORITY); 580 return t; 581 } 582 } 583 584 /** 585 * Thread factory capturing access control context and class loader 586 */ 587 static class PrivilegedThreadFactory extends DefaultThreadFactory { 588 private final AccessControlContext acc; 589 private final ClassLoader ccl; 590 591 PrivilegedThreadFactory() { 592 super(); 593 SecurityManager sm = System.getSecurityManager(); 594 if (sm != null) { 595 // Calls to getContextClassLoader from this class 596 // never trigger a security check, but we check 597 // whether our callers have this permission anyways. 598 sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION); 599 600 // Fail fast 601 sm.checkPermission(new RuntimePermission("setContextClassLoader")); 602 } 603 this.acc = AccessController.getContext(); 604 this.ccl = Thread.currentThread().getContextClassLoader(); 605 } 606 607 public Thread newThread(final Runnable r) { 608 return super.newThread(new Runnable() { 609 public void run() { 610 AccessController.doPrivileged(new PrivilegedAction<Void>() { 611 public Void run() { 612 Thread.currentThread().setContextClassLoader(ccl); 613 r.run(); 614 return null; 615 } 616 }, acc); 617 } 618 }); 619 } 620 } 621 622 /** 623 * A wrapper class that exposes only the ExecutorService methods 624 * of an ExecutorService implementation. 625 */ 626 static class DelegatedExecutorService extends AbstractExecutorService { 627 private final ExecutorService e; 628 DelegatedExecutorService(ExecutorService executor) { e = executor; } 629 public void execute(Runnable command) { e.execute(command); } 630 public void shutdown() { e.shutdown(); } 631 public List<Runnable> shutdownNow() { return e.shutdownNow(); } 632 public boolean isShutdown() { return e.isShutdown(); } 633 public boolean isTerminated() { return e.isTerminated(); } 634 public boolean awaitTermination(long timeout, TimeUnit unit) 635 throws InterruptedException { 636 return e.awaitTermination(timeout, unit); 637 } 638 public Future<?> submit(Runnable task) { 639 return e.submit(task); 640 } 641 public <T> Future<T> submit(Callable<T> task) { 642 return e.submit(task); 643 } 644 public <T> Future<T> submit(Runnable task, T result) { 645 return e.submit(task, result); 646 } 647 public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks) 648 throws InterruptedException { 649 return e.invokeAll(tasks); 650 } 651 public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks, 652 long timeout, TimeUnit unit) 653 throws InterruptedException { 654 return e.invokeAll(tasks, timeout, unit); 655 } 656 public <T> T invokeAny(Collection<? extends Callable<T>> tasks) 657 throws InterruptedException, ExecutionException { 658 return e.invokeAny(tasks); 659 } 660 public <T> T invokeAny(Collection<? extends Callable<T>> tasks, 661 long timeout, TimeUnit unit) 662 throws InterruptedException, ExecutionException, TimeoutException { 663 return e.invokeAny(tasks, timeout, unit); 664 } 665 } 666 667 static class FinalizableDelegatedExecutorService 668 extends DelegatedExecutorService { 669 FinalizableDelegatedExecutorService(ExecutorService executor) { 670 super(executor); 671 } 672 protected void finalize() { 673 super.shutdown(); 674 } 675 } 676 677 /** 678 * A wrapper class that exposes only the ScheduledExecutorService 679 * methods of a ScheduledExecutorService implementation. 680 */ 681 static class DelegatedScheduledExecutorService 682 extends DelegatedExecutorService 683 implements ScheduledExecutorService { 684 private final ScheduledExecutorService e; 685 DelegatedScheduledExecutorService(ScheduledExecutorService executor) { 686 super(executor); 687 e = executor; 688 } 689 public ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) { 690 return e.schedule(command, delay, unit); 691 } 692 public <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit) { 693 return e.schedule(callable, delay, unit); 694 } 695 public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit) { 696 return e.scheduleAtFixedRate(command, initialDelay, period, unit); 697 } 698 public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long initialDelay, long delay, TimeUnit unit) { 699 return e.scheduleWithFixedDelay(command, initialDelay, delay, unit); 700 } 701 } 702 703 704 /** Cannot instantiate. */ 705 private Executors() {} 706 } --- EOF ---