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.Comparator;
import java.util.List;
import java.util.Set;
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.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);
    }

    ArrayList<Integer> results;

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

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

    /**
     * The second "solvers" sample code in the class javadoc works.
     */
    public void testSolveAny()
        throws InterruptedException {
        results = null;
        Set<Callable<Integer>> solvers = Set.of(
            () -> { throw new ArithmeticException(); },
            () -> null,
            () -> 1,
            () -> 2);
        solveAny(cachedThreadPool, solvers);
        assertEquals(1, results.size());
        Integer elt = results.get(0);
        assertTrue(elt.equals(1) || elt.equals(2));
    }

}
Revision:	1.9
Committed:	Wed Jan 27 01:57:24 2021 UTC (3 years, 3 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.8:	+1 -1 lines
Log Message:	use diamond <> pervasively
#	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	jsr166	1.6	import java.util.Comparator;
11	jsr166	1.1	import java.util.List;
12			import java.util.Set;
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.Future;
19
20			import junit.framework.Test;
21			import junit.framework.TestSuite;
22
23			public class ExecutorCompletionService9Test extends JSR166TestCase {
24			public static void main(String[] args) {
25			main(suite(), args);
26			}
27			public static Test suite() {
28			return new TestSuite(ExecutorCompletionService9Test.class);
29			}
30
31			void solveAll(Executor e,
32			Collection<Callable<Integer>> solvers)
33			throws InterruptedException, ExecutionException {
34			CompletionService<Integer> cs
35			= new ExecutorCompletionService<>(e);
36	jsr166	1.4	solvers.forEach(cs::submit);
37	jsr166	1.1	for (int i = solvers.size(); i > 0; i--) {
38			Integer r = cs.take().get();
39			if (r != null)
40			use(r);
41			}
42			}
43
44			void solveAny(Executor e,
45			Collection<Callable<Integer>> solvers)
46			throws InterruptedException {
47			CompletionService<Integer> cs
48			= new ExecutorCompletionService<>(e);
49			int n = solvers.size();
50			List<Future<Integer>> futures = new ArrayList<>(n);
51			Integer result = null;
52			try {
53	jsr166	1.7	solvers.forEach(solver -> futures.add(cs.submit(solver)));
54	jsr166	1.1	for (int i = n; i > 0; i--) {
55			try {
56			Integer r = cs.take().get();
57			if (r != null) {
58			result = r;
59			break;
60			}
61			} catch (ExecutionException ignore) {}
62			}
63			} finally {
64	jsr166	1.7	futures.forEach(future -> future.cancel(true));
65	jsr166	1.1	}
66
67			if (result != null)
68			use(result);
69			}
70
71	jsr166	1.6	ArrayList<Integer> results;
72	jsr166	1.1
73			void use(Integer x) {
74	jsr166	1.9	if (results == null) results = new ArrayList<>();
75	jsr166	1.1	results.add(x);
76			}
77
78			/**
79			* The first "solvers" sample code in the class javadoc works.
80			*/
81			public void testSolveAll()
82			throws InterruptedException, ExecutionException {
83	jsr166	1.6	results = null;
84	jsr166	1.1	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	1.6	results.sort(Comparator.naturalOrder());
92			assertEquals(List.of(1, 2, 3), results);
93	jsr166	1.1	}
94	jsr166	1.2
95	jsr166	1.1	/**
96			* The second "solvers" sample code in the class javadoc works.
97			*/
98			public void testSolveAny()
99			throws InterruptedException {
100	jsr166	1.6	results = null;
101	jsr166	1.1	Set<Callable<Integer>> solvers = Set.of(
102			() -> { throw new ArithmeticException(); },
103			() -> null,
104			() -> 1,
105			() -> 2);
106	jsr166	1.3	solveAny(cachedThreadPool, solvers);
107	jsr166	1.1	assertEquals(1, results.size());
108	jsr166	1.6	Integer elt = results.get(0);
109	jsr166	1.1	assertTrue(elt.equals(1) \|\| elt.equals(2));
110			}
111
112			}