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/* |
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* Written by Doug Lea and Martin Buchholz with assistance from |
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* members of JCP JSR-166 Expert Group and released to the public |
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* domain, as explained at |
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* http://creativecommons.org/publicdomain/zero/1.0/ |
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*/ |
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|
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import java.util.ArrayList; |
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import java.util.Collection; |
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import java.util.List; |
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import java.util.Set; |
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import java.util.HashSet; |
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import java.util.concurrent.Callable; |
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import java.util.concurrent.CompletionService; |
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import java.util.concurrent.ExecutionException; |
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import java.util.concurrent.Executor; |
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import java.util.concurrent.ExecutorCompletionService; |
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import java.util.concurrent.ExecutorService; |
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import java.util.concurrent.Future; |
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|
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import junit.framework.Test; |
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import junit.framework.TestSuite; |
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|
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public class ExecutorCompletionService9Test extends JSR166TestCase { |
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public static void main(String[] args) { |
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main(suite(), args); |
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} |
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public static Test suite() { |
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return new TestSuite(ExecutorCompletionService9Test.class); |
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} |
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|
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void solveAll(Executor e, |
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Collection<Callable<Integer>> solvers) |
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throws InterruptedException, ExecutionException { |
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CompletionService<Integer> cs |
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= new ExecutorCompletionService<>(e); |
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solvers.forEach(cs::submit); |
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for (int i = solvers.size(); i > 0; i--) { |
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Integer r = cs.take().get(); |
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if (r != null) |
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use(r); |
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} |
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} |
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|
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void solveAny(Executor e, |
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Collection<Callable<Integer>> solvers) |
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throws InterruptedException { |
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CompletionService<Integer> cs |
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= new ExecutorCompletionService<>(e); |
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int n = solvers.size(); |
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List<Future<Integer>> futures = new ArrayList<>(n); |
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Integer result = null; |
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try { |
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solvers.forEach((solver) -> futures.add(cs.submit(solver))); |
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for (int i = n; i > 0; i--) { |
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try { |
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Integer r = cs.take().get(); |
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if (r != null) { |
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result = r; |
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break; |
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} |
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} catch (ExecutionException ignore) {} |
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} |
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} finally { |
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futures.forEach((future) -> future.cancel(true)); |
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} |
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|
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if (result != null) |
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use(result); |
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} |
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|
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HashSet<Integer> results; |
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|
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void use(Integer x) { |
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if (results == null) results = new HashSet<Integer>(); |
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results.add(x); |
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} |
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|
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/** |
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* The first "solvers" sample code in the class javadoc works. |
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*/ |
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public void testSolveAll() |
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throws InterruptedException, ExecutionException { |
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Set<Callable<Integer>> solvers = Set.of( |
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() -> null, |
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() -> 1, |
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() -> 2, |
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() -> 3, |
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() -> null); |
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solveAll(cachedThreadPool, solvers); |
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assertEquals(Set.of(1, 2, 3), results); |
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} |
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|
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/** |
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* The second "solvers" sample code in the class javadoc works. |
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*/ |
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public void testSolveAny() |
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throws InterruptedException { |
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Set<Callable<Integer>> solvers = Set.of( |
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() -> { throw new ArithmeticException(); }, |
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() -> null, |
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() -> 1, |
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() -> 2); |
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solveAny(cachedThreadPool, solvers); |
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assertEquals(1, results.size()); |
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Integer elt = results.iterator().next(); |
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assertTrue(elt.equals(1) || elt.equals(2)); |
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} |
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|
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} |
