1 /*
2 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
3 *
4 *
5 *
6 *
7 *
8 *
9 *
10 *
11 *
12 *
13 *
14 *
15 *
16 *
17 *
18 *
19 *
20 *
21 *
22 *
23 */
24
25 /*
26 *
27 *
28 *
29 *
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/publicdomain/zero/1.0/
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 {@code Callable}.
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 * {@code nThreads} 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 {@code nThreads <= 0}
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 maintains enough threads to support
96 * the given parallelism level, and may use multiple queues to
97 * reduce contention. The parallelism level corresponds to the
98 * maximum number of threads actively engaged in, or available to
99 * engage in, task processing. The actual number of threads may
100 * grow and shrink dynamically. A work-stealing pool makes no
101 * guarantees about the order in which submitted tasks are
102 * executed.
103 *
104 * @param parallelism the targeted parallelism level
105 * @return the newly created thread pool
106 * @throws IllegalArgumentException if {@code parallelism <= 0}
107 * @since 1.8
108 */
109 public static ExecutorService newWorkStealingPool(int parallelism) {
110 return new ForkJoinPool
111 (parallelism,
112 ForkJoinPool.defaultForkJoinWorkerThreadFactory,
113 null, true);
114 }
115
116 /**
117 * Creates a work-stealing thread pool using all
118 * {@link Runtime#availableProcessors available processors}
119 * as its target parallelism level.
120 * @return the newly created thread pool
121 * @see #newWorkStealingPool(int)
122 * @since 1.8
123 */
124 public static ExecutorService newWorkStealingPool() {
125 return new ForkJoinPool
126 (Runtime.getRuntime().availableProcessors(),
127 ForkJoinPool.defaultForkJoinWorkerThreadFactory,
128 null, true);
129 }
130
131 /**
132 * Creates a thread pool that reuses a fixed number of threads
133 * operating off a shared unbounded queue, using the provided
134 * ThreadFactory to create new threads when needed. At any point,
135 * at most {@code nThreads} threads will be active processing
136 * tasks. If additional tasks are submitted when all threads are
137 * active, they will wait in the queue until a thread is
138 * available. If any thread terminates due to a failure during
139 * execution prior to shutdown, a new one will take its place if
140 * needed to execute subsequent tasks. The threads in the pool will
141 * exist until it is explicitly {@link ExecutorService#shutdown
142 * shutdown}.
143 *
144 * @param nThreads the number of threads in the pool
145 * @param threadFactory the factory to use when creating new threads
146 * @return the newly created thread pool
147 * @throws NullPointerException if threadFactory is null
148 * @throws IllegalArgumentException if {@code nThreads <= 0}
149 */
150 public static ExecutorService newFixedThreadPool(int nThreads, ThreadFactory threadFactory) {
151 return new ThreadPoolExecutor(nThreads, nThreads,
152 0L, TimeUnit.MILLISECONDS,
153 new LinkedBlockingQueue<Runnable>(),
154 threadFactory);
155 }
156
157 /**
158 * Creates an Executor that uses a single worker thread operating
159 * off an unbounded queue. (Note however that if this single
160 * thread terminates due to a failure during execution prior to
161 * shutdown, a new one will take its place if needed to execute
162 * subsequent tasks.) Tasks are guaranteed to execute
163 * sequentially, and no more than one task will be active at any
164 * given time. Unlike the otherwise equivalent
165 * {@code newFixedThreadPool(1)} the returned executor is
166 * guaranteed not to be reconfigurable to use additional threads.
167 *
168 * @return the newly created single-threaded Executor
169 */
170 public static ExecutorService newSingleThreadExecutor() {
171 return new FinalizableDelegatedExecutorService
172 (new ThreadPoolExecutor(1, 1,
173 0L, TimeUnit.MILLISECONDS,
174 new LinkedBlockingQueue<Runnable>()));
175 }
176
177 /**
178 * Creates an Executor that uses a single worker thread operating
179 * off an unbounded queue, and uses the provided ThreadFactory to
180 * create a new thread when needed. Unlike the otherwise
181 * equivalent {@code newFixedThreadPool(1, threadFactory)} the
182 * returned executor is guaranteed not to be reconfigurable to use
183 * additional threads.
184 *
185 * @param threadFactory the factory to use when creating new
186 * threads
187 *
188 * @return the newly created single-threaded Executor
189 * @throws NullPointerException if threadFactory is null
190 */
191 public static ExecutorService newSingleThreadExecutor(ThreadFactory threadFactory) {
192 return new FinalizableDelegatedExecutorService
193 (new ThreadPoolExecutor(1, 1,
194 0L, TimeUnit.MILLISECONDS,
195 new LinkedBlockingQueue<Runnable>(),
196 threadFactory));
197 }
198
199 /**
200 * Creates a thread pool that creates new threads as needed, but
201 * will reuse previously constructed threads when they are
202 * available. These pools will typically improve the performance
203 * of programs that execute many short-lived asynchronous tasks.
204 * Calls to {@code execute} will reuse previously constructed
205 * threads if available. If no existing thread is available, a new
206 * thread will be created and added to the pool. Threads that have
207 * not been used for sixty seconds are terminated and removed from
208 * the cache. Thus, a pool that remains idle for long enough will
209 * not consume any resources. Note that pools with similar
210 * properties but different details (for example, timeout parameters)
211 * may be created using {@link ThreadPoolExecutor} constructors.
212 *
213 * @return the newly created thread pool
214 */
215 public static ExecutorService newCachedThreadPool() {
216 return new ThreadPoolExecutor(0, Integer.MAX_VALUE,
217 60L, TimeUnit.SECONDS,
218 new SynchronousQueue<Runnable>());
219 }
220
221 /**
222 * Creates a thread pool that creates new threads as needed, but
223 * will reuse previously constructed threads when they are
224 * available, and uses the provided
225 * ThreadFactory to create new threads when needed.
226 * @param threadFactory the factory to use when creating new threads
227 * @return the newly created thread pool
228 * @throws NullPointerException if threadFactory is null
229 */
230 public static ExecutorService newCachedThreadPool(ThreadFactory threadFactory) {
231 return new ThreadPoolExecutor(0, Integer.MAX_VALUE,
232 60L, TimeUnit.SECONDS,
233 new SynchronousQueue<Runnable>(),
234 threadFactory);
235 }
236
237 /**
238 * Creates a single-threaded executor that can schedule commands
239 * to run after a given delay, or to execute periodically.
240 * (Note however that if this single
241 * thread terminates due to a failure during execution prior to
242 * shutdown, a new one will take its place if needed to execute
243 * subsequent tasks.) Tasks are guaranteed to execute
244 * sequentially, and no more than one task will be active at any
245 * given time. Unlike the otherwise equivalent
246 * {@code newScheduledThreadPool(1)} the returned executor is
247 * guaranteed not to be reconfigurable to use additional threads.
248 * @return the newly created scheduled executor
249 */
250 public static ScheduledExecutorService newSingleThreadScheduledExecutor() {
251 return new DelegatedScheduledExecutorService
252 (new ScheduledThreadPoolExecutor(1));
253 }
254
255 /**
256 * Creates a single-threaded executor that can schedule commands
257 * to run after a given delay, or to execute periodically. (Note
258 * however that if this single thread terminates due to a failure
259 * during execution prior to shutdown, a new one will take its
260 * place if needed to execute subsequent tasks.) Tasks are
261 * guaranteed to execute sequentially, and no more than one task
262 * will be active at any given time. Unlike the otherwise
263 * equivalent {@code newScheduledThreadPool(1, threadFactory)}
264 * the returned executor is guaranteed not to be reconfigurable to
265 * use additional threads.
266 * @param threadFactory the factory to use when creating new
267 * threads
268 * @return a newly created scheduled executor
269 * @throws NullPointerException if threadFactory is null
270 */
271 public static ScheduledExecutorService newSingleThreadScheduledExecutor(ThreadFactory threadFactory) {
272 return new DelegatedScheduledExecutorService
273 (new ScheduledThreadPoolExecutor(1, threadFactory));
274 }
275
276 /**
277 * Creates a thread pool that can schedule commands to run after a
278 * given delay, or to execute periodically.
279 * @param corePoolSize the number of threads to keep in the pool,
280 * even if they are idle
281 * @return a newly created scheduled thread pool
282 * @throws IllegalArgumentException if {@code corePoolSize < 0}
283 */
284 public static ScheduledExecutorService newScheduledThreadPool(int corePoolSize) {
285 return new ScheduledThreadPoolExecutor(corePoolSize);
286 }
287
288 /**
289 * Creates a thread pool that can schedule commands to run after a
290 * given delay, or to execute periodically.
291 * @param corePoolSize the number of threads to keep in the pool,
292 * even if they are idle
293 * @param threadFactory the factory to use when the executor
294 * creates a new thread
295 * @return a newly created scheduled thread pool
296 * @throws IllegalArgumentException if {@code corePoolSize < 0}
297 * @throws NullPointerException if threadFactory is null
298 */
299 public static ScheduledExecutorService newScheduledThreadPool(
300 int corePoolSize, ThreadFactory threadFactory) {
301 return new ScheduledThreadPoolExecutor(corePoolSize, threadFactory);
302 }
303
304 /**
305 * Returns an object that delegates all defined {@link
306 * ExecutorService} methods to the given executor, but not any
307 * other methods that might otherwise be accessible using
308 * casts. This provides a way to safely "freeze" configuration and
309 * disallow tuning of a given concrete implementation.
310 * @param executor the underlying implementation
311 * @return an {@code ExecutorService} instance
312 * @throws NullPointerException if executor null
313 */
314 public static ExecutorService unconfigurableExecutorService(ExecutorService executor) {
315 if (executor == null)
316 throw new NullPointerException();
317 return new DelegatedExecutorService(executor);
318 }
319
320 /**
321 * Returns an object that delegates all defined {@link
322 * ScheduledExecutorService} methods to the given executor, but
323 * not any other methods that might otherwise be accessible using
324 * casts. This provides a way to safely "freeze" configuration and
325 * disallow tuning of a given concrete implementation.
326 * @param executor the underlying implementation
327 * @return a {@code ScheduledExecutorService} instance
328 * @throws NullPointerException if executor null
329 */
330 public static ScheduledExecutorService unconfigurableScheduledExecutorService(ScheduledExecutorService executor) {
331 if (executor == null)
332 throw new NullPointerException();
333 return new DelegatedScheduledExecutorService(executor);
334 }
335
336 /**
337 * Returns a default thread factory used to create new threads.
338 * This factory creates all new threads used by an Executor in the
339 * same {@link ThreadGroup}. If there is a {@link
340 * java.lang.SecurityManager}, it uses the group of {@link
341 * System#getSecurityManager}, else the group of the thread
342 * invoking this {@code defaultThreadFactory} method. Each new
343 * thread is created as a non-daemon thread with priority set to
344 * the smaller of {@code Thread.NORM_PRIORITY} and the maximum
345 * priority permitted in the thread group. New threads have names
346 * accessible via {@link Thread#getName} of
347 * <em>pool-N-thread-M</em>, where <em>N</em> is the sequence
348 * number of this factory, and <em>M</em> is the sequence number
349 * of the thread created by this factory.
350 * @return a thread factory
351 */
352 public static ThreadFactory defaultThreadFactory() {
353 return new DefaultThreadFactory();
354 }
355
356 /**
357 * Returns a thread factory used to create new threads that
358 * have the same permissions as the current thread.
359 * This factory creates threads with the same settings as {@link
360 * Executors#defaultThreadFactory}, additionally setting the
361 * AccessControlContext and contextClassLoader of new threads to
362 * be the same as the thread invoking this
363 * {@code privilegedThreadFactory} method. A new
364 * {@code privilegedThreadFactory} can be created within an
365 * {@link AccessController#doPrivileged AccessController.doPrivileged}
366 * action setting the current thread's access control context to
367 * create threads with the selected permission settings holding
368 * within that action.
369 *
370 * <p>Note that while tasks running within such threads will have
371 * the same access control and class loader settings as the
372 * current thread, they need not have the same {@link
373 * java.lang.ThreadLocal} or {@link
374 * java.lang.InheritableThreadLocal} values. If necessary,
375 * particular values of thread locals can be set or reset before
376 * any task runs in {@link ThreadPoolExecutor} subclasses using
377 * {@link ThreadPoolExecutor#beforeExecute(Thread, Runnable)}.
378 * Also, if it is necessary to initialize worker threads to have
379 * the same InheritableThreadLocal settings as some other
380 * designated thread, you can create a custom ThreadFactory in
381 * which that thread waits for and services requests to create
382 * others that will inherit its values.
383 *
384 * @return a thread factory
385 * @throws AccessControlException if the current access control
386 * context does not have permission to both get and set context
387 * class loader
388 */
389 public static ThreadFactory privilegedThreadFactory() {
390 return new PrivilegedThreadFactory();
391 }
392
393 /**
394 * Returns a {@link Callable} object that, when
395 * called, runs the given task and returns the given result. This
396 * can be useful when applying methods requiring a
397 * {@code Callable} to an otherwise resultless action.
398 * @param task the task to run
399 * @param result the result to return
400 * @param <T> the type of the result
401 * @return a callable object
402 * @throws NullPointerException if task null
403 */
404 public static <T> Callable<T> callable(Runnable task, T result) {
405 if (task == null)
406 throw new NullPointerException();
407 return new RunnableAdapter<T>(task, result);
408 }
409
410 /**
411 * Returns a {@link Callable} object that, when
412 * called, runs the given task and returns {@code null}.
413 * @param task the task to run
414 * @return a callable object
415 * @throws NullPointerException if task null
416 */
417 public static Callable<Object> callable(Runnable task) {
418 if (task == null)
419 throw new NullPointerException();
420 return new RunnableAdapter<Object>(task, null);
421 }
422
423 /**
424 * Returns a {@link Callable} object that, when
425 * called, runs the given privileged action and returns its result.
426 * @param action the privileged action to run
427 * @return a callable object
428 * @throws NullPointerException if action null
429 */
430 public static Callable<Object> callable(final PrivilegedAction<?> action) {
431 if (action == null)
432 throw new NullPointerException();
433 return new Callable<Object>() {
434 public Object call() { return action.run(); }};
435 }
436
437 /**
438 * Returns a {@link Callable} object that, when
439 * called, runs the given privileged exception action and returns
440 * its result.
441 * @param action the privileged exception action to run
442 * @return a callable object
443 * @throws NullPointerException if action null
444 */
445 public static Callable<Object> callable(final PrivilegedExceptionAction<?> action) {
446 if (action == null)
447 throw new NullPointerException();
448 return new Callable<Object>() {
449 public Object call() throws Exception { return action.run(); }};
450 }
451
452 /**
453 * Returns a {@link Callable} object that will, when called,
454 * execute the given {@code callable} under the current access
455 * control context. This method should normally be invoked within
456 * an {@link AccessController#doPrivileged AccessController.doPrivileged}
457 * action to create callables that will, if possible, execute
458 * under the selected permission settings holding within that
459 * action; or if not possible, throw an associated {@link
460 * AccessControlException}.
461 * @param callable the underlying task
462 * @param <T> the type of the callable's result
463 * @return a callable object
464 * @throws NullPointerException if callable null
465 */
466 public static <T> Callable<T> privilegedCallable(Callable<T> callable) {
467 if (callable == null)
468 throw new NullPointerException();
469 return new PrivilegedCallable<T>(callable);
470 }
471
472 /**
473 * Returns a {@link Callable} object that will, when called,
474 * execute the given {@code callable} under the current access
475 * control context, with the current context class loader as the
476 * context class loader. This method should normally be invoked
477 * within an
478 * {@link AccessController#doPrivileged AccessController.doPrivileged}
479 * action to create callables that will, if possible, execute
480 * under the selected permission settings holding within that
481 * action; or if not possible, throw an associated {@link
482 * AccessControlException}.
483 *
484 * @param callable the underlying task
485 * @param <T> the type of the callable's result
486 * @return a callable object
487 * @throws NullPointerException if callable null
488 * @throws AccessControlException if the current access control
489 * context does not have permission to both set and get context
490 * class loader
491 */
492 public static <T> Callable<T> privilegedCallableUsingCurrentClassLoader(Callable<T> callable) {
493 if (callable == null)
494 throw new NullPointerException();
495 return new PrivilegedCallableUsingCurrentClassLoader<T>(callable);
496 }
497
498 // Non-public classes supporting the public methods
499
500 /**
501 * A callable that runs given task and returns given result
502 */
503 static final class RunnableAdapter<T> implements Callable<T> {
504 final Runnable task;
505 final T result;
506 RunnableAdapter(Runnable task, T result) {
507 this.task = task;
508 this.result = result;
509 }
510 public T call() {
511 task.run();
512 return result;
513 }
514 }
515
516 /**
517 * A callable that runs under established access control settings
518 */
519 static final class PrivilegedCallable<T> implements Callable<T> {
520 private final Callable<T> task;
521 private final AccessControlContext acc;
522
523 PrivilegedCallable(Callable<T> task) {
524 this.task = task;
525 this.acc = AccessController.getContext();
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 return task.call();
534 }
535 }, acc);
536 } catch (PrivilegedActionException e) {
537 throw e.getException();
538 }
539 }
540 }
541
542 /**
543 * A callable that runs under established access control settings and
544 * current ClassLoader
545 */
546 static final class PrivilegedCallableUsingCurrentClassLoader<T> implements Callable<T> {
547 private final Callable<T> task;
548 private final AccessControlContext acc;
549 private final ClassLoader ccl;
550
551 PrivilegedCallableUsingCurrentClassLoader(Callable<T> task) {
552 SecurityManager sm = System.getSecurityManager();
553 if (sm != null) {
554 // Calls to getContextClassLoader from this class
555 // never trigger a security check, but we check
556 // whether our callers have this permission anyways.
557 sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION);
558
559 // Whether setContextClassLoader turns out to be necessary
560 // or not, we fail fast if permission is not available.
561 sm.checkPermission(new RuntimePermission("setContextClassLoader"));
562 }
563 this.task = task;
564 this.acc = AccessController.getContext();
565 this.ccl = Thread.currentThread().getContextClassLoader();
566 }
567
568 public T call() throws Exception {
569 try {
570 return AccessController.doPrivileged(
571 new PrivilegedExceptionAction<T>() {
572 public T run() throws Exception {
573 Thread t = Thread.currentThread();
574 ClassLoader cl = t.getContextClassLoader();
575 if (ccl == cl) {
576 return task.call();
577 } else {
578 t.setContextClassLoader(ccl);
579 try {
580 return task.call();
581 } finally {
582 t.setContextClassLoader(cl);
583 }
584 }
585 }
586 }, acc);
587 } catch (PrivilegedActionException e) {
588 throw e.getException();
589 }
590 }
591 }
592
593 /**
594 * The default thread factory
595 */
596 static class DefaultThreadFactory implements ThreadFactory {
597 private static final AtomicInteger poolNumber = new AtomicInteger(1);
598 private final ThreadGroup group;
599 private final AtomicInteger threadNumber = new AtomicInteger(1);
600 private final String namePrefix;
601
602 DefaultThreadFactory() {
603 SecurityManager s = System.getSecurityManager();
604 group = (s != null) ? s.getThreadGroup() :
605 Thread.currentThread().getThreadGroup();
606 namePrefix = "pool-" +
607 poolNumber.getAndIncrement() +
608 "-thread-";
609 }
610
611 public Thread newThread(Runnable r) {
612 Thread t = new Thread(group, r,
613 namePrefix + threadNumber.getAndIncrement(),
614 0);
615 if (t.isDaemon())
616 t.setDaemon(false);
617 if (t.getPriority() != Thread.NORM_PRIORITY)
618 t.setPriority(Thread.NORM_PRIORITY);
619 return t;
620 }
621 }
622
623 /**
624 * Thread factory capturing access control context and class loader
625 */
626 static class PrivilegedThreadFactory extends DefaultThreadFactory {
627 private final AccessControlContext acc;
628 private final ClassLoader ccl;
629
630 PrivilegedThreadFactory() {
631 super();
632 SecurityManager sm = System.getSecurityManager();
633 if (sm != null) {
634 // Calls to getContextClassLoader from this class
635 // never trigger a security check, but we check
636 // whether our callers have this permission anyways.
637 sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION);
638
639 // Fail fast
640 sm.checkPermission(new RuntimePermission("setContextClassLoader"));
641 }
642 this.acc = AccessController.getContext();
643 this.ccl = Thread.currentThread().getContextClassLoader();
644 }
645
646 public Thread newThread(final Runnable r) {
647 return super.newThread(new Runnable() {
648 public void run() {
649 AccessController.doPrivileged(new PrivilegedAction<Void>() {
650 public Void run() {
651 Thread.currentThread().setContextClassLoader(ccl);
652 r.run();
653 return null;
654 }
655 }, acc);
656 }
657 });
658 }
659 }
660
661 /**
662 * A wrapper class that exposes only the ExecutorService methods
663 * of an ExecutorService implementation.
664 */
665 static class DelegatedExecutorService extends AbstractExecutorService {
666 private final ExecutorService e;
667 DelegatedExecutorService(ExecutorService executor) { e = executor; }
668 public void execute(Runnable command) { e.execute(command); }
669 public void shutdown() { e.shutdown(); }
670 public List<Runnable> shutdownNow() { return e.shutdownNow(); }
671 public boolean isShutdown() { return e.isShutdown(); }
672 public boolean isTerminated() { return e.isTerminated(); }
673 public boolean awaitTermination(long timeout, TimeUnit unit)
674 throws InterruptedException {
675 return e.awaitTermination(timeout, unit);
676 }
677 public Future<?> submit(Runnable task) {
678 return e.submit(task);
679 }
680 public <T> Future<T> submit(Callable<T> task) {
681 return e.submit(task);
682 }
683 public <T> Future<T> submit(Runnable task, T result) {
684 return e.submit(task, result);
685 }
686 public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks)
687 throws InterruptedException {
688 return e.invokeAll(tasks);
689 }
690 public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks,
691 long timeout, TimeUnit unit)
692 throws InterruptedException {
693 return e.invokeAll(tasks, timeout, unit);
694 }
695 public <T> T invokeAny(Collection<? extends Callable<T>> tasks)
696 throws InterruptedException, ExecutionException {
697 return e.invokeAny(tasks);
698 }
699 public <T> T invokeAny(Collection<? extends Callable<T>> tasks,
700 long timeout, TimeUnit unit)
701 throws InterruptedException, ExecutionException, TimeoutException {
702 return e.invokeAny(tasks, timeout, unit);
703 }
704 }
705
706 static class FinalizableDelegatedExecutorService
707 extends DelegatedExecutorService {
708 FinalizableDelegatedExecutorService(ExecutorService executor) {
709 super(executor);
710 }
711 protected void finalize() {
712 super.shutdown();
713 }
714 }
715
716 /**
717 * A wrapper class that exposes only the ScheduledExecutorService
718 * methods of a ScheduledExecutorService implementation.
719 */
720 static class DelegatedScheduledExecutorService
721 extends DelegatedExecutorService
722 implements ScheduledExecutorService {
723 private final ScheduledExecutorService e;
724 DelegatedScheduledExecutorService(ScheduledExecutorService executor) {
725 super(executor);
726 e = executor;
727 }
728 public ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
729 return e.schedule(command, delay, unit);
730 }
731 public <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit) {
732 return e.schedule(callable, delay, unit);
733 }
734 public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit) {
735 return e.scheduleAtFixedRate(command, initialDelay, period, unit);
736 }
737 public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long initialDelay, long delay, TimeUnit unit) {
738 return e.scheduleWithFixedDelay(command, initialDelay, delay, unit);
739 }
740 }
741
742 /** Cannot instantiate. */
743 private Executors() {}
744 }
745