test/tck/ExecutorCompletionService9Test.java

/*
 * Written by Doug Lea and Martin Buchholz with assistance from
 * members of JCP JSR-166 Expert Group and released to the public
 * domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Set;
import java.util.HashSet;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;

import junit.framework.Test;
import junit.framework.TestSuite;

public class ExecutorCompletionService9Test extends JSR166TestCase {
    public static void main(String[] args) {
        main(suite(), args);
    }
    public static Test suite() {
        return new TestSuite(ExecutorCompletionService9Test.class);
    }

    void solveAll(Executor e,
                  Collection<Callable<Integer>> solvers)
        throws InterruptedException, ExecutionException {
        CompletionService<Integer> cs
            = new ExecutorCompletionService<>(e);
        solvers.forEach(cs::submit);
        for (int i = solvers.size(); i > 0; i--) {
            Integer r = cs.take().get();
            if (r != null)
                use(r);
        }
    }

    void solveAny(Executor e,
                  Collection<Callable<Integer>> solvers)
        throws InterruptedException {
        CompletionService<Integer> cs
            = new ExecutorCompletionService<>(e);
        int n = solvers.size();
        List<Future<Integer>> futures = new ArrayList<>(n);
        Integer result = null;
        try {
            solvers.forEach((solver) -> futures.add(cs.submit(solver)));
            for (int i = n; i > 0; i--) {
                try {
                    Integer r = cs.take().get();
                    if (r != null) {
                        result = r;
                        break;
                    }
                } catch (ExecutionException ignore) {}
            }
        } finally {
            futures.forEach((future) -> future.cancel(true));
        }

        if (result != null)
            use(result);
    }

    HashSet<Integer> results;

    void use(Integer x) {
        if (results == null) results = new HashSet<Integer>();
        results.add(x);
    }

    /**
     * The first "solvers" sample code in the class javadoc works.
     */
    public void testSolveAll()
        throws InterruptedException, ExecutionException {
        Set<Callable<Integer>> solvers = Set.of(
            () -> null,
            () -> 1,
            () -> 2,
            () -> 3,
            () -> null);
        solveAll(cachedThreadPool, solvers);
        assertEquals(Set.of(1, 2, 3), results);
    }

    /**
     * The second "solvers" sample code in the class javadoc works.
     */
    public void testSolveAny()
        throws InterruptedException {
        Set<Callable<Integer>> solvers = Set.of(
            () -> { throw new ArithmeticException(); },
            () -> null,
            () -> 1,
            () -> 2);
        solveAny(cachedThreadPool, solvers);
        assertEquals(1, results.size());
        Integer elt = results.iterator().next();
        assertTrue(elt.equals(1) || elt.equals(2));
    }

}
Revision:	1.4
Committed:	Mon May 23 22:58:06 2016 UTC (7 years, 11 months ago) by jsr166
Branch:	MAIN
Changes since 1.3:	+1 -1 lines
Log Message:	use method references
#	User	Rev	Content
1	jsr166	1.1	/*
2			* Written by Doug Lea and Martin Buchholz with assistance from
3			* members of JCP JSR-166 Expert Group and released to the public
4			* domain, as explained at
5			* http://creativecommons.org/publicdomain/zero/1.0/
6			*/
7
8			import java.util.ArrayList;
9			import java.util.Collection;
10			import java.util.List;
11			import java.util.Set;
12			import java.util.HashSet;
13			import java.util.concurrent.Callable;
14			import java.util.concurrent.CompletionService;
15			import java.util.concurrent.ExecutionException;
16	jsr166	1.3	import java.util.concurrent.Executor;
17	jsr166	1.1	import java.util.concurrent.ExecutorCompletionService;
18			import java.util.concurrent.ExecutorService;
19			import java.util.concurrent.Future;
20
21			import junit.framework.Test;
22			import junit.framework.TestSuite;
23
24			public class ExecutorCompletionService9Test extends JSR166TestCase {
25			public static void main(String[] args) {
26			main(suite(), args);
27			}
28			public static Test suite() {
29			return new TestSuite(ExecutorCompletionService9Test.class);
30			}
31
32			void solveAll(Executor e,
33			Collection<Callable<Integer>> solvers)
34			throws InterruptedException, ExecutionException {
35			CompletionService<Integer> cs
36			= new ExecutorCompletionService<>(e);
37	jsr166	1.4	solvers.forEach(cs::submit);
38	jsr166	1.1	for (int i = solvers.size(); i > 0; i--) {
39			Integer r = cs.take().get();
40			if (r != null)
41			use(r);
42			}
43			}
44
45			void solveAny(Executor e,
46			Collection<Callable<Integer>> solvers)
47			throws InterruptedException {
48			CompletionService<Integer> cs
49			= new ExecutorCompletionService<>(e);
50			int n = solvers.size();
51			List<Future<Integer>> futures = new ArrayList<>(n);
52			Integer result = null;
53			try {
54			solvers.forEach((solver) -> futures.add(cs.submit(solver)));
55			for (int i = n; i > 0; i--) {
56			try {
57			Integer r = cs.take().get();
58			if (r != null) {
59			result = r;
60			break;
61			}
62			} catch (ExecutionException ignore) {}
63			}
64			} finally {
65			futures.forEach((future) -> future.cancel(true));
66			}
67
68			if (result != null)
69			use(result);
70			}
71
72			HashSet<Integer> results;
73
74			void use(Integer x) {
75			if (results == null) results = new HashSet<Integer>();
76			results.add(x);
77			}
78
79			/**
80			* The first "solvers" sample code in the class javadoc works.
81			*/
82			public void testSolveAll()
83			throws InterruptedException, ExecutionException {
84			Set<Callable<Integer>> solvers = Set.of(
85			() -> null,
86			() -> 1,
87			() -> 2,
88			() -> 3,
89			() -> null);
90	jsr166	1.3	solveAll(cachedThreadPool, solvers);
91	jsr166	1.1	assertEquals(Set.of(1, 2, 3), results);
92			}
93	jsr166	1.2
94	jsr166	1.1	/**
95			* The second "solvers" sample code in the class javadoc works.
96			*/
97			public void testSolveAny()
98			throws InterruptedException {
99			Set<Callable<Integer>> solvers = Set.of(
100			() -> { throw new ArithmeticException(); },
101			() -> null,
102			() -> 1,
103			() -> 2);
104	jsr166	1.3	solveAny(cachedThreadPool, solvers);
105	jsr166	1.1	assertEquals(1, results.size());
106			Integer elt = results.iterator().next();
107			assertTrue(elt.equals(1) \|\| elt.equals(2));
108			}
109
110			}