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.util.*;

/**
 * Provides default implementation of {@link ExecutorService}
 * execution methods. This class implements the <tt>submit</tt>,
 * <tt>invokeAny</tt> and <tt>invokeAll</tt> methods using the default
 * {@link FutureTask} class 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) {
        if (task == null) throw new NullPointerException();
        FutureTask<Object> ftask = new FutureTask<Object>(task, null);
        execute(ftask);
        return ftask;
    }

    public <T> Future<T> submit(Runnable task, T result) {
        if (task == null) throw new NullPointerException();
        FutureTask<T> ftask = new FutureTask<T>(task, result);
        execute(ftask);
        return ftask;
    }

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

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


    public <T> T invokeAny(Collection<Callable<T>> tasks)
        throws InterruptedException, ExecutionException {
        if (tasks == null)
            throw new NullPointerException();
        int n = tasks.size();
        if (n == 0)
            throw new IllegalArgumentException();
        List<Future<T>> futures= new ArrayList<Future<T>>(n);
        ExecutorCompletionService<T> ecs = 
            new ExecutorCompletionService<T>(this);
        try {
            for (Callable<T> t : tasks) 
                futures.add(ecs.submit(t));
            ExecutionException ee = null;
            RuntimeException re = null;
            while (n-- > 0) {
                Future<T> f = ecs.take();
                try {
                    return f.get();
                } catch(ExecutionException eex) {
                    ee = eex;
                } catch(RuntimeException rex) {
                    re = rex;
                }
            }    
            if (ee != null)
                throw ee;
            if (re != null)
                throw new ExecutionException(re);
            throw new ExecutionException();
        } finally {
            for (Future<T> f : futures) 
                f.cancel(true);
        }
    }

    public <T> T invokeAny(Collection<Callable<T>> tasks, 
                           long timeout, TimeUnit unit) 
        throws InterruptedException, ExecutionException, TimeoutException {
        if (tasks == null || unit == null)
            throw new NullPointerException();
        long nanos = unit.toNanos(timeout);
        int n = tasks.size();
        if (n == 0)
            throw new IllegalArgumentException();
        List<Future<T>> futures= new ArrayList<Future<T>>(n);
        ExecutorCompletionService<T> ecs = 
            new ExecutorCompletionService<T>(this);
        try {
            for (Callable<T> t : tasks) 
                futures.add(ecs.submit(t));
            ExecutionException ee = null;
            RuntimeException re = null;
            long lastTime = System.nanoTime();
            while (n-- > 0) {
                Future<T> f = ecs.poll(nanos, TimeUnit.NANOSECONDS);
                if (f == null)
                    throw new TimeoutException();
                try {
                    return f.get();
                } catch(ExecutionException eex) {
                    ee = eex;
                } catch(RuntimeException rex) {
                    re = rex;
                }
                long now = System.nanoTime();
                nanos -= now - lastTime;
                lastTime = now;
            }    
            if (ee != null)
                throw ee;
            if (re != null)
                throw new ExecutionException(re);
            throw new ExecutionException();
        } finally {
            for (Future<T> f : futures) 
                f.cancel(true);
        }
    }

    public <T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks)
        throws InterruptedException {
        if (tasks == null)
            throw new NullPointerException();
        List<Future<T>> futures = new ArrayList<Future<T>>(tasks.size());
        boolean done = false;
        try {
            for (Callable<T> t : tasks) {
                FutureTask<T> f = new FutureTask<T>(t);
                futures.add(f);
                execute(f);
            }
            for (Future<T> f : futures) {
                if (!f.isDone()) {
                    try { 
                        f.get(); 
                    } catch(CancellationException ignore) {
                    } catch(ExecutionException ignore) {
                    }
                }
            }
            done = true;
            return futures;
        } finally {
            if (!done)
                for (Future<T> f : futures) 
                    f.cancel(true);
        }
    }

    public <T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks, 
                                         long timeout, TimeUnit unit) 
        throws InterruptedException {
        if (tasks == null || unit == null)
            throw new NullPointerException();
        long nanos = unit.toNanos(timeout);
        List<Future<T>> futures = new ArrayList<Future<T>>(tasks.size());
        boolean done = false;
        try {
            for (Callable<T> t : tasks) {
                FutureTask<T> f = new FutureTask<T>(t);
                futures.add(f);
                execute(f);
            }
            long lastTime = System.nanoTime();
            for (Future<T> f : futures) {
                if (!f.isDone()) {
                    if (nanos < 0) 
                        return futures; 
                    try { 
                        f.get(nanos, TimeUnit.NANOSECONDS); 
                    } catch(CancellationException ignore) {
                    } catch(ExecutionException ignore) {
                    } catch(TimeoutException toe) {
                        return futures;
                    }
                    long now = System.nanoTime();
                    nanos -= now - lastTime;
                    lastTime = now;
                }
            }
            done = true;
            return futures;
        } finally {
            if (!done)
                for (Future<T> f : futures) 
                    f.cancel(true);
        }
    }

}
Revision:	1.13
Committed:	Sun Dec 21 12:24:48 2003 UTC (20 years, 5 months ago) by dl
Branch:	MAIN
Changes since 1.12:	+9 -0 lines
Log Message:	Documentation improvments; support two-arg submit
#	User	Rev	Content
1	tim	1.1	/*
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	dl	1.3	import java.util.*;
10	tim	1.1
11			/**
12	dl	1.2	* Provides default implementation of {@link ExecutorService}
13	dl	1.12	* execution methods. This class implements the <tt>submit</tt>,
14			* <tt>invokeAny</tt> and <tt>invokeAll</tt> methods using the default
15			* {@link FutureTask} class provided in this package. For example,
16			* the the implementation of <tt>submit(Runnable)</tt> creates an
17			* associated <tt>FutureTask</tt> that is executed and
18	dl	1.2	* returned. Subclasses overriding these methods to use different
19			* {@link Future} implementations should do so consistently for each
20			* of these methods.
21	tim	1.1	*
22			* @since 1.5
23			* @author Doug Lea
24			*/
25			public abstract class AbstractExecutorService implements ExecutorService {
26
27	dl	1.11	public Future<?> submit(Runnable task) {
28	dl	1.13	if (task == null) throw new NullPointerException();
29	dl	1.11	FutureTask<Object> ftask = new FutureTask<Object>(task, null);
30	tim	1.1	execute(ftask);
31			return ftask;
32			}
33
34	dl	1.13	public <T> Future<T> submit(Runnable task, T result) {
35			if (task == null) throw new NullPointerException();
36			FutureTask<T> ftask = new FutureTask<T>(task, result);
37			execute(ftask);
38			return ftask;
39			}
40
41	tim	1.1	public <T> Future<T> submit(Callable<T> task) {
42	dl	1.13	if (task == null) throw new NullPointerException();
43	tim	1.1	FutureTask<T> ftask = new FutureTask<T>(task);
44			execute(ftask);
45			return ftask;
46			}
47
48	dl	1.7	// any/all methods, each a little bit different than the other
49	dl	1.3
50
51	dl	1.7	public <T> T invokeAny(Collection<Callable<T>> tasks)
52			throws InterruptedException, ExecutionException {
53	dl	1.3	if (tasks == null)
54			throw new NullPointerException();
55			int n = tasks.size();
56			if (n == 0)
57	dl	1.7	throw new IllegalArgumentException();
58			List<Future<T>> futures= new ArrayList<Future<T>>(n);
59			ExecutorCompletionService<T> ecs =
60			new ExecutorCompletionService<T>(this);
61	dl	1.3	try {
62	dl	1.7	for (Callable<T> t : tasks)
63			futures.add(ecs.submit(t));
64			ExecutionException ee = null;
65			RuntimeException re = null;
66			while (n-- > 0) {
67			Future<T> f = ecs.take();
68			try {
69			return f.get();
70			} catch(ExecutionException eex) {
71			ee = eex;
72			} catch(RuntimeException rex) {
73			re = rex;
74			}
75			}
76			if (ee != null)
77			throw ee;
78			if (re != null)
79			throw new ExecutionException(re);
80			throw new ExecutionException();
81	dl	1.3	} finally {
82	dl	1.6	for (Future<T> f : futures)
83	dl	1.4	f.cancel(true);
84	dl	1.3	}
85			}
86
87	dl	1.7	public <T> T invokeAny(Collection<Callable<T>> tasks,
88			long timeout, TimeUnit unit)
89			throws InterruptedException, ExecutionException, TimeoutException {
90	dl	1.3	if (tasks == null \|\| unit == null)
91			throw new NullPointerException();
92	dl	1.7	long nanos = unit.toNanos(timeout);
93	dl	1.3	int n = tasks.size();
94			if (n == 0)
95	dl	1.7	throw new IllegalArgumentException();
96			List<Future<T>> futures= new ArrayList<Future<T>>(n);
97			ExecutorCompletionService<T> ecs =
98			new ExecutorCompletionService<T>(this);
99	dl	1.3	try {
100	dl	1.7	for (Callable<T> t : tasks)
101			futures.add(ecs.submit(t));
102			ExecutionException ee = null;
103			RuntimeException re = null;
104			long lastTime = System.nanoTime();
105			while (n-- > 0) {
106			Future<T> f = ecs.poll(nanos, TimeUnit.NANOSECONDS);
107	dl	1.8	if (f == null)
108			throw new TimeoutException();
109	dl	1.7	try {
110			return f.get();
111			} catch(ExecutionException eex) {
112			ee = eex;
113			} catch(RuntimeException rex) {
114			re = rex;
115			}
116	dl	1.8	long now = System.nanoTime();
117			nanos -= now - lastTime;
118			lastTime = now;
119	dl	1.7	}
120			if (ee != null)
121			throw ee;
122			if (re != null)
123			throw new ExecutionException(re);
124			throw new ExecutionException();
125	dl	1.3	} finally {
126	dl	1.6	for (Future<T> f : futures)
127	dl	1.4	f.cancel(true);
128	dl	1.3	}
129			}
130
131	dl	1.9	public <T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks)
132	dl	1.3	throws InterruptedException {
133			if (tasks == null)
134			throw new NullPointerException();
135	dl	1.6	List<Future<T>> futures = new ArrayList<Future<T>>(tasks.size());
136			boolean done = false;
137	dl	1.3	try {
138			for (Callable<T> t : tasks) {
139	dl	1.6	FutureTask<T> f = new FutureTask<T>(t);
140	dl	1.3	futures.add(f);
141			execute(f);
142			}
143	dl	1.6	for (Future<T> f : futures) {
144			if (!f.isDone()) {
145			try {
146			f.get();
147			} catch(CancellationException ignore) {
148			} catch(ExecutionException ignore) {
149			}
150			}
151			}
152			done = true;
153	dl	1.3	return futures;
154			} finally {
155	dl	1.6	if (!done)
156	dl	1.4	for (Future<T> f : futures)
157			f.cancel(true);
158	dl	1.3	}
159			}
160
161	dl	1.9	public <T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks,
162	dl	1.6	long timeout, TimeUnit unit)
163	dl	1.3	throws InterruptedException {
164			if (tasks == null \|\| unit == null)
165			throw new NullPointerException();
166			long nanos = unit.toNanos(timeout);
167	dl	1.6	List<Future<T>> futures = new ArrayList<Future<T>>(tasks.size());
168			boolean done = false;
169	dl	1.3	try {
170			for (Callable<T> t : tasks) {
171	dl	1.6	FutureTask<T> f = new FutureTask<T>(t);
172	dl	1.3	futures.add(f);
173			execute(f);
174			}
175	dl	1.6	long lastTime = System.nanoTime();
176			for (Future<T> f : futures) {
177			if (!f.isDone()) {
178			if (nanos < 0)
179			return futures;
180			try {
181			f.get(nanos, TimeUnit.NANOSECONDS);
182			} catch(CancellationException ignore) {
183			} catch(ExecutionException ignore) {
184			} catch(TimeoutException toe) {
185			return futures;
186			}
187	dl	1.8	long now = System.nanoTime();
188			nanos -= now - lastTime;
189			lastTime = now;
190	dl	1.6	}
191			}
192			done = true;
193	dl	1.3	return futures;
194			} finally {
195	dl	1.6	if (!done)
196	dl	1.4	for (Future<T> f : futures)
197			f.cancel(true);
198	dl	1.3	}
199			}
200
201	tim	1.1	}