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/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
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* Expert Group and released to the public 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.concurrent.*; |
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|
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public class ExecutorCompletionServiceLoops { |
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static final int POOLSIZE = 100; |
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static final ExecutorService pool = |
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Executors.newFixedThreadPool(POOLSIZE); |
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static final ExecutorCompletionService<Integer> ecs = |
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new ExecutorCompletionService<Integer>(pool); |
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static boolean print = false; |
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|
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public static void main(String[] args) throws Exception { |
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int max = 8; |
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int base = 10000; |
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|
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if (args.length > 0) |
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max = Integer.parseInt(args[0]); |
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|
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System.out.println("Warmup..."); |
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oneTest( base ); |
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Thread.sleep(100); |
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print = true; |
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|
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for (int i = 1; i <= max; i += (i+1) >>> 1) { |
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System.out.print("n: " + i * base); |
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oneTest(i * base ); |
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Thread.sleep(100); |
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} |
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pool.shutdown(); |
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} |
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|
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static class Task implements Callable<Integer> { |
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public Integer call() { |
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int l = System.identityHashCode(this); |
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l = LoopHelpers.compute2(l); |
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int s = LoopHelpers.compute1(l); |
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l = LoopHelpers.compute2(l); |
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s += LoopHelpers.compute1(l); |
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return new Integer(s); |
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} |
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} |
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|
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static class Producer implements Runnable { |
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final ExecutorCompletionService cs; |
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final int iters; |
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Producer(ExecutorCompletionService ecs, int i) { |
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cs = ecs; |
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iters = i; |
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} |
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public void run() { |
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for (int i = 0; i < iters; ++i) |
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ecs.submit(new Task()); |
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} |
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} |
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|
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static void oneTest(int iters) throws Exception { |
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long startTime = System.nanoTime(); |
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new Thread(new Producer(ecs, iters)).start(); |
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|
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int r = 0; |
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for (int i = 0; i < iters; ++i) |
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r += ecs.take().get().intValue(); |
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|
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long elapsed = System.nanoTime() - startTime; |
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long tpi = elapsed/ iters; |
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|
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if (print) |
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System.out.println("\t: " + LoopHelpers.rightJustify(tpi) + " ns per task"); |
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|
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if (r == 0) // avoid overoptimization |
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System.out.println("useless result: " + r); |
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} |
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|
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} |
