util/concurrent/AbstractExecutorService.java

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain. Use, modify, and
 * redistribute this code in any way without acknowledgement.
 */

package java.util.concurrent;

import java.security.AccessControlContext;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedExceptionAction;
import java.util.*;
import java.util.concurrent.locks.*;

/**
 * Provides default implementation of {@link ExecutorService}
 * execution methods. This class implements the <tt>submit</tt> and
 * <tt>invoke</tt> methods using the default {@link FutureTask} and
 * {@link PrivilegedFutureTask} classes provided in this package.  For
 * example, the the implementation of <tt>submit(Runnable)</tt>
 * creates an associated <tt>FutureTask</tt> that is executed and
 * returned. Subclasses overriding these methods to use different
 * {@link Future} implementations should do so consistently for each
 * of these methods.
 *
 * @since 1.5
 * @author Doug Lea
 */
public abstract class AbstractExecutorService implements ExecutorService {

    public Future<?> submit(Runnable task) {
        FutureTask<?> ftask = new FutureTask<Boolean>(task, Boolean.TRUE);
        execute(ftask);
        return ftask;
    }

    public <T> Future<T> submit(Callable<T> task) {
        FutureTask<T> ftask = new FutureTask<T>(task);
        execute(ftask);
        return ftask;
    }

    public void invoke(Runnable task) throws ExecutionException, InterruptedException {
        FutureTask<?> ftask = new FutureTask<Boolean>(task, Boolean.TRUE);
        execute(ftask);
        ftask.get();
    }

    public <T> T invoke(Callable<T> task) throws ExecutionException, InterruptedException {
        FutureTask<T> ftask = new FutureTask<T>(task);
        execute(ftask);
        return ftask.get();
    }

    public Future<Object> submit(PrivilegedAction action) {
        Callable<Object> task = new PrivilegedActionAdapter(action);
        FutureTask<Object> future = new PrivilegedFutureTask<Object>(task);
        execute(future);
        return future;
    }

    public Future<Object> submit(PrivilegedExceptionAction action) {
        Callable<Object> task = new PrivilegedExceptionActionAdapter(action);
        FutureTask<Object> future = new PrivilegedFutureTask<Object>(task);
        execute(future);
        return future;
    }

    private static class PrivilegedActionAdapter implements Callable<Object> {
        PrivilegedActionAdapter(PrivilegedAction action) {
            this.action = action;
        }
        public Object call () {
            return action.run();
        }
        private final PrivilegedAction action;
    }
    
    private static class PrivilegedExceptionActionAdapter implements Callable<Object> {
        PrivilegedExceptionActionAdapter(PrivilegedExceptionAction action) {
            this.action = action;
        }
        public Object call () throws Exception {
            return action.run();
        }
        private final PrivilegedExceptionAction action;
    }

    /**
     * Helper class to wait for tasks in bulk-execute methods
     */
    private static class TaskGroupWaiter {
        private final ReentrantLock lock = new ReentrantLock();
        private final Condition done = lock.newCondition();
        private int firstIndex = -1;
        private int countDown;
        TaskGroupWaiter(int ntasks) { countDown = ntasks; }

        void signalDone(int index) {
            lock.lock();
            try {
                if (firstIndex < 0)
                    firstIndex = index;
                if (--countDown == 0)
                    done.signalAll();
            } finally {
                lock.unlock();
            }
        }

        int await() throws InterruptedException {
            lock.lock();
            try {
                while (countDown > 0)
                    done.await();
                return firstIndex;
            } finally {
                lock.unlock();
            }
        }

        int awaitNanos(long nanos) throws InterruptedException {
            lock.lock();
            try {
                while (countDown > 0 && nanos > 0)
                    nanos = done.awaitNanos(nanos);
                return firstIndex;
            } finally {
                lock.unlock();
            }
        }

        boolean isDone() {
            lock.lock();
            try {
                return countDown <= 0;
            } finally {
                lock.unlock();
            }
        }
    }

    /**
     * FutureTask extension to provide signal when task completes
     */
    private static class SignallingFuture<T> extends FutureTask<T> {
        private final TaskGroupWaiter waiter;
        private final int index;
        SignallingFuture(Callable<T> c, TaskGroupWaiter w, int i) { 
            super(c); waiter = w; index = i;
        }
        SignallingFuture(Runnable t, T r, TaskGroupWaiter w, int i) {
            super(t, r); waiter = w; index = i;
        }
        protected void done() {
            waiter.signalDone(index);
        }
    }

    // any/all methods, each a little bit different than the other

    public List<Future<?>> runAny(List<Runnable> tasks)
        throws InterruptedException {
        if (tasks == null)
            throw new NullPointerException();
        int n = tasks.size();
        List<Future<?>> futures = new ArrayList<Future<?>>(n);
        if (n == 0)
            return futures;
        TaskGroupWaiter waiter = new TaskGroupWaiter(1);
        try {
            int i = 0;
            for (Runnable t : tasks) {
                SignallingFuture<Boolean> f = 
                    new SignallingFuture<Boolean>(t, Boolean.TRUE, waiter, i++);
                futures.add(f);
                if (!waiter.isDone())
                    execute(f);
            }
            int first = waiter.await();
            return futures;
        } finally {
            for (Future<?> f : futures) 
                f.cancel(true);
        }
    }

    public List<Future<?>> runAny(List<Runnable> tasks, 
                                  long timeout, TimeUnit unit) 
        throws InterruptedException {
        if (tasks == null || unit == null)
            throw new NullPointerException();
        long nanos = unit.toNanos(timeout);
        int n = tasks.size();
        List<Future<?>> futures = new ArrayList<Future<?>>(n);
        if (n == 0)
            return futures;
        TaskGroupWaiter waiter = new TaskGroupWaiter(1);
        try {
            int i = 0;
            for (Runnable t : tasks) {
                SignallingFuture<Boolean> f = 
                    new SignallingFuture<Boolean>(t, Boolean.TRUE, waiter, i++);
                futures.add(f);
                if (!waiter.isDone())
                    execute(f);
            }
            int first = waiter.awaitNanos(nanos);
            return futures;
        } finally {
            for (Future<?> f : futures) 
                f.cancel(true);
        }
    }


    public List<Future<?>> runAll(List<Runnable> tasks)
        throws InterruptedException {
        if (tasks == null)
            throw new NullPointerException();
        int n = tasks.size();
        List<Future<?>> futures = new ArrayList<Future<?>>(n);
        if (n == 0)
            return futures;
        TaskGroupWaiter waiter = new TaskGroupWaiter(n);
        int i = 0;
        try {
            for (Runnable t : tasks) {
                SignallingFuture<Boolean> f = 
                    new SignallingFuture<Boolean>(t, Boolean.TRUE, waiter, i++);
                futures.add(f);
                execute(f);
            }
            waiter.await();
            return futures;
        } finally {
            if (!waiter.isDone())
                for (Future<?> f : futures) 
                    f.cancel(true);
        }
    }

    public List<Future<?>> runAll(List<Runnable> tasks, 
                                  long timeout, TimeUnit unit) 
        throws InterruptedException {
        if (tasks == null || unit == null)
            throw new NullPointerException();
        long nanos = unit.toNanos(timeout);
        int n = tasks.size();
        List<Future<?>> futures = new ArrayList<Future<?>>(n);
        if (n == 0)
            return futures;
        TaskGroupWaiter waiter = new TaskGroupWaiter(n);
        try {
            int i = 0;
            for (Runnable t : tasks) {
                SignallingFuture<Boolean> f = 
                    new SignallingFuture<Boolean>(t, Boolean.TRUE, waiter, i++);
                futures.add(f);
                execute(f);
            }
            waiter.awaitNanos(nanos);
            return futures;
        } finally {
            if (!waiter.isDone())
                for (Future<?> f : futures) 
                    f.cancel(true);
        }
    }

    public <T> List<Future<T>> callAny(List<Callable<T>> tasks)
        throws InterruptedException {
        if (tasks == null)
            throw new NullPointerException();
        int n = tasks.size();
        List<Future<T>> futures = new ArrayList<Future<T>>(n);
        if (n == 0)
            return futures;
        TaskGroupWaiter waiter = new TaskGroupWaiter(1);
        int i = 0;
        try {
            for (Callable<T> t : tasks) {
                SignallingFuture<T> f = new SignallingFuture<T>(t, waiter, i++);
                futures.add(f);
                if (!waiter.isDone())
                    execute(f);
            }
            int first = waiter.await();
            return futures;
        } finally {
            for (Future<T> f : futures) 
                f.cancel(true);
        }
    }

    public <T> List<Future<T>> callAny(List<Callable<T>> tasks, 
                                       long timeout, TimeUnit unit) 
        throws InterruptedException {
        if (tasks == null || unit == null)
            throw new NullPointerException();
        long nanos = unit.toNanos(timeout);
        int n = tasks.size();
        List<Future<T>> futures= new ArrayList<Future<T>>(n);
        if (n == 0)
            return futures;
        TaskGroupWaiter waiter = new TaskGroupWaiter(1);
        try {
            int i = 0;
            for (Callable<T> t : tasks) {
                SignallingFuture<T> f = new SignallingFuture<T>(t, waiter, i++);
                futures.add(f);
                if (!waiter.isDone())
                    execute(f);
            }
            int first = waiter.awaitNanos(nanos);
            return futures;
        } finally {
            for (Future<T> f : futures) 
                f.cancel(true);
        }
    }


    public <T> List<Future<T>> callAll(List<Callable<T>> tasks)
        throws InterruptedException {
        if (tasks == null)
            throw new NullPointerException();
        int n = tasks.size();
        List<Future<T>> futures = new ArrayList<Future<T>>(n);
        if (n == 0)
            return futures;
        TaskGroupWaiter waiter = new TaskGroupWaiter(n);
        try {
            int i = 0;
            for (Callable<T> t : tasks) {
                SignallingFuture<T> f = new SignallingFuture<T>(t, waiter, i++);
                futures.add(f);
                execute(f);
            }
            waiter.await();
            return futures;
        } finally {
            if (!waiter.isDone())
                for (Future<T> f : futures) 
                    f.cancel(true);
        }
    }

    public <T> List<Future<T>> callAll(List<Callable<T>> tasks, 
                                       long timeout, TimeUnit unit) 
        throws InterruptedException {
        if (tasks == null || unit == null)
            throw new NullPointerException();
        long nanos = unit.toNanos(timeout);
        int n = tasks.size();
        List<Future<T>> futures = new ArrayList<Future<T>>(n);
        if (n == 0)
            return futures;
        TaskGroupWaiter waiter = new TaskGroupWaiter(n);
        try {
            int i = 0;
            for (Callable<T> t : tasks) {
                SignallingFuture<T> f = new SignallingFuture<T>(t, waiter, i++);
                futures.add(f);
                execute(f);
            }
            waiter.awaitNanos(nanos);
            return futures;
        } finally {
            if (!waiter.isDone())
                for (Future<T> f : futures) 
                    f.cancel(true);
        }
    }

}
Revision:	1.5
Committed:	Mon Dec 15 00:29:49 2003 UTC (20 years, 5 months ago) by dl
Branch:	MAIN
Changes since 1.4:	+8 -16 lines
Log Message:	Added CompletionService; Executor any/all methods now require lists
#	Content
1	/*
2	* Written by Doug Lea with assistance from members of JCP JSR-166
3	* Expert Group and released to the public domain. Use, modify, and
4	* redistribute this code in any way without acknowledgement.
5	*/
6
7	package java.util.concurrent;
8
9	import java.security.AccessControlContext;
10	import java.security.AccessController;
11	import java.security.PrivilegedAction;
12	import java.security.PrivilegedExceptionAction;
13	import java.util.*;
14	import java.util.concurrent.locks.*;
15
16	/**
17	* Provides default implementation of {@link ExecutorService}
18	* execution methods. This class implements the <tt>submit</tt> and
19	* <tt>invoke</tt> methods using the default {@link FutureTask} and
20	* {@link PrivilegedFutureTask} classes provided in this package. For
21	* example, the the implementation of <tt>submit(Runnable)</tt>
22	* creates an associated <tt>FutureTask</tt> that is executed and
23	* returned. Subclasses overriding these methods to use different
24	* {@link Future} implementations should do so consistently for each
25	* of these methods.
26	*
27	* @since 1.5
28	* @author Doug Lea
29	*/
30	public abstract class AbstractExecutorService implements ExecutorService {
31
32	public Future<?> submit(Runnable task) {
33	FutureTask<?> ftask = new FutureTask<Boolean>(task, Boolean.TRUE);
34	execute(ftask);
35	return ftask;
36	}
37
38	public <T> Future<T> submit(Callable<T> task) {
39	FutureTask<T> ftask = new FutureTask<T>(task);
40	execute(ftask);
41	return ftask;
42	}
43
44	public void invoke(Runnable task) throws ExecutionException, InterruptedException {
45	FutureTask<?> ftask = new FutureTask<Boolean>(task, Boolean.TRUE);
46	execute(ftask);
47	ftask.get();
48	}
49
50	public <T> T invoke(Callable<T> task) throws ExecutionException, InterruptedException {
51	FutureTask<T> ftask = new FutureTask<T>(task);
52	execute(ftask);
53	return ftask.get();
54	}
55
56	public Future<Object> submit(PrivilegedAction action) {
57	Callable<Object> task = new PrivilegedActionAdapter(action);
58	FutureTask<Object> future = new PrivilegedFutureTask<Object>(task);
59	execute(future);
60	return future;
61	}
62
63	public Future<Object> submit(PrivilegedExceptionAction action) {
64	Callable<Object> task = new PrivilegedExceptionActionAdapter(action);
65	FutureTask<Object> future = new PrivilegedFutureTask<Object>(task);
66	execute(future);
67	return future;
68	}
69
70	private static class PrivilegedActionAdapter implements Callable<Object> {
71	PrivilegedActionAdapter(PrivilegedAction action) {
72	this.action = action;
73	}
74	public Object call () {
75	return action.run();
76	}
77	private final PrivilegedAction action;
78	}
79
80	private static class PrivilegedExceptionActionAdapter implements Callable<Object> {
81	PrivilegedExceptionActionAdapter(PrivilegedExceptionAction action) {
82	this.action = action;
83	}
84	public Object call () throws Exception {
85	return action.run();
86	}
87	private final PrivilegedExceptionAction action;
88	}
89
90	/**
91	* Helper class to wait for tasks in bulk-execute methods
92	*/
93	private static class TaskGroupWaiter {
94	private final ReentrantLock lock = new ReentrantLock();
95	private final Condition done = lock.newCondition();
96	private int firstIndex = -1;
97	private int countDown;
98	TaskGroupWaiter(int ntasks) { countDown = ntasks; }
99
100	void signalDone(int index) {
101	lock.lock();
102	try {
103	if (firstIndex < 0)
104	firstIndex = index;
105	if (--countDown == 0)
106	done.signalAll();
107	} finally {
108	lock.unlock();
109	}
110	}
111
112	int await() throws InterruptedException {
113	lock.lock();
114	try {
115	while (countDown > 0)
116	done.await();
117	return firstIndex;
118	} finally {
119	lock.unlock();
120	}
121	}
122
123	int awaitNanos(long nanos) throws InterruptedException {
124	lock.lock();
125	try {
126	while (countDown > 0 && nanos > 0)
127	nanos = done.awaitNanos(nanos);
128	return firstIndex;
129	} finally {
130	lock.unlock();
131	}
132	}
133
134	boolean isDone() {
135	lock.lock();
136	try {
137	return countDown <= 0;
138	} finally {
139	lock.unlock();
140	}
141	}
142	}
143
144	/**
145	* FutureTask extension to provide signal when task completes
146	*/
147	private static class SignallingFuture<T> extends FutureTask<T> {
148	private final TaskGroupWaiter waiter;
149	private final int index;
150	SignallingFuture(Callable<T> c, TaskGroupWaiter w, int i) {
151	super(c); waiter = w; index = i;
152	}
153	SignallingFuture(Runnable t, T r, TaskGroupWaiter w, int i) {
154	super(t, r); waiter = w; index = i;
155	}
156	protected void done() {
157	waiter.signalDone(index);
158	}
159	}
160
161	// any/all methods, each a little bit different than the other
162
163	public List<Future<?>> runAny(List<Runnable> tasks)
164	throws InterruptedException {
165	if (tasks == null)
166	throw new NullPointerException();
167	int n = tasks.size();
168	List<Future<?>> futures = new ArrayList<Future<?>>(n);
169	if (n == 0)
170	return futures;
171	TaskGroupWaiter waiter = new TaskGroupWaiter(1);
172	try {
173	int i = 0;
174	for (Runnable t : tasks) {
175	SignallingFuture<Boolean> f =
176	new SignallingFuture<Boolean>(t, Boolean.TRUE, waiter, i++);
177	futures.add(f);
178	if (!waiter.isDone())
179	execute(f);
180	}
181	int first = waiter.await();
182	return futures;
183	} finally {
184	for (Future<?> f : futures)
185	f.cancel(true);
186	}
187	}
188
189	public List<Future<?>> runAny(List<Runnable> tasks,
190	long timeout, TimeUnit unit)
191	throws InterruptedException {
192	if (tasks == null \|\| unit == null)
193	throw new NullPointerException();
194	long nanos = unit.toNanos(timeout);
195	int n = tasks.size();
196	List<Future<?>> futures = new ArrayList<Future<?>>(n);
197	if (n == 0)
198	return futures;
199	TaskGroupWaiter waiter = new TaskGroupWaiter(1);
200	try {
201	int i = 0;
202	for (Runnable t : tasks) {
203	SignallingFuture<Boolean> f =
204	new SignallingFuture<Boolean>(t, Boolean.TRUE, waiter, i++);
205	futures.add(f);
206	if (!waiter.isDone())
207	execute(f);
208	}
209	int first = waiter.awaitNanos(nanos);
210	return futures;
211	} finally {
212	for (Future<?> f : futures)
213	f.cancel(true);
214	}
215	}
216
217
218
219	public List<Future<?>> runAll(List<Runnable> tasks)
220	throws InterruptedException {
221	if (tasks == null)
222	throw new NullPointerException();
223	int n = tasks.size();
224	List<Future<?>> futures = new ArrayList<Future<?>>(n);
225	if (n == 0)
226	return futures;
227	TaskGroupWaiter waiter = new TaskGroupWaiter(n);
228	int i = 0;
229	try {
230	for (Runnable t : tasks) {
231	SignallingFuture<Boolean> f =
232	new SignallingFuture<Boolean>(t, Boolean.TRUE, waiter, i++);
233	futures.add(f);
234	execute(f);
235	}
236	waiter.await();
237	return futures;
238	} finally {
239	if (!waiter.isDone())
240	for (Future<?> f : futures)
241	f.cancel(true);
242	}
243	}
244
245	public List<Future<?>> runAll(List<Runnable> tasks,
246	long timeout, TimeUnit unit)
247	throws InterruptedException {
248	if (tasks == null \|\| unit == null)
249	throw new NullPointerException();
250	long nanos = unit.toNanos(timeout);
251	int n = tasks.size();
252	List<Future<?>> futures = new ArrayList<Future<?>>(n);
253	if (n == 0)
254	return futures;
255	TaskGroupWaiter waiter = new TaskGroupWaiter(n);
256	try {
257	int i = 0;
258	for (Runnable t : tasks) {
259	SignallingFuture<Boolean> f =
260	new SignallingFuture<Boolean>(t, Boolean.TRUE, waiter, i++);
261	futures.add(f);
262	execute(f);
263	}
264	waiter.awaitNanos(nanos);
265	return futures;
266	} finally {
267	if (!waiter.isDone())
268	for (Future<?> f : futures)
269	f.cancel(true);
270	}
271	}
272
273	public <T> List<Future<T>> callAny(List<Callable<T>> tasks)
274	throws InterruptedException {
275	if (tasks == null)
276	throw new NullPointerException();
277	int n = tasks.size();
278	List<Future<T>> futures = new ArrayList<Future<T>>(n);
279	if (n == 0)
280	return futures;
281	TaskGroupWaiter waiter = new TaskGroupWaiter(1);
282	int i = 0;
283	try {
284	for (Callable<T> t : tasks) {
285	SignallingFuture<T> f = new SignallingFuture<T>(t, waiter, i++);
286	futures.add(f);
287	if (!waiter.isDone())
288	execute(f);
289	}
290	int first = waiter.await();
291	return futures;
292	} finally {
293	for (Future<T> f : futures)
294	f.cancel(true);
295	}
296	}
297
298	public <T> List<Future<T>> callAny(List<Callable<T>> tasks,
299	long timeout, TimeUnit unit)
300	throws InterruptedException {
301	if (tasks == null \|\| unit == null)
302	throw new NullPointerException();
303	long nanos = unit.toNanos(timeout);
304	int n = tasks.size();
305	List<Future<T>> futures= new ArrayList<Future<T>>(n);
306	if (n == 0)
307	return futures;
308	TaskGroupWaiter waiter = new TaskGroupWaiter(1);
309	try {
310	int i = 0;
311	for (Callable<T> t : tasks) {
312	SignallingFuture<T> f = new SignallingFuture<T>(t, waiter, i++);
313	futures.add(f);
314	if (!waiter.isDone())
315	execute(f);
316	}
317	int first = waiter.awaitNanos(nanos);
318	return futures;
319	} finally {
320	for (Future<T> f : futures)
321	f.cancel(true);
322	}
323	}
324
325
326	public <T> List<Future<T>> callAll(List<Callable<T>> tasks)
327	throws InterruptedException {
328	if (tasks == null)
329	throw new NullPointerException();
330	int n = tasks.size();
331	List<Future<T>> futures = new ArrayList<Future<T>>(n);
332	if (n == 0)
333	return futures;
334	TaskGroupWaiter waiter = new TaskGroupWaiter(n);
335	try {
336	int i = 0;
337	for (Callable<T> t : tasks) {
338	SignallingFuture<T> f = new SignallingFuture<T>(t, waiter, i++);
339	futures.add(f);
340	execute(f);
341	}
342	waiter.await();
343	return futures;
344	} finally {
345	if (!waiter.isDone())
346	for (Future<T> f : futures)
347	f.cancel(true);
348	}
349	}
350
351	public <T> List<Future<T>> callAll(List<Callable<T>> tasks,
352	long timeout, TimeUnit unit)
353	throws InterruptedException {
354	if (tasks == null \|\| unit == null)
355	throw new NullPointerException();
356	long nanos = unit.toNanos(timeout);
357	int n = tasks.size();
358	List<Future<T>> futures = new ArrayList<Future<T>>(n);
359	if (n == 0)
360	return futures;
361	TaskGroupWaiter waiter = new TaskGroupWaiter(n);
362	try {
363	int i = 0;
364	for (Callable<T> t : tasks) {
365	SignallingFuture<T> f = new SignallingFuture<T>(t, waiter, i++);
366	futures.add(f);
367	execute(f);
368	}
369	waiter.awaitNanos(nanos);
370	return futures;
371	} finally {
372	if (!waiter.isDone())
373	for (Future<T> f : futures)
374	f.cancel(true);
375	}
376	}
377
378	}