test/loops/CachedThreadPoolLoops.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.
 */

import java.util.concurrent.*;
import java.util.concurrent.atomic.*;

public class CachedThreadPoolLoops {
    static final AtomicInteger remaining = new AtomicInteger();
    static final int maxIters = 1000000;

    public static void main(String[] args) throws Exception {
        int maxThreads = 100;

        if (args.length > 0) 
            maxThreads = Integer.parseInt(args[0]);

        System.out.print("Warmup:");
        for (int j = 0; j < 2; ++j) {
            int k = 1;
            for (int i = 1; i <= maxThreads;) {
                System.out.print(" " + i);
                oneTest(i, 10000, false);
                Thread.sleep(100);
                if (i == k) {
                    k = i << 1;
                    i = i + (i >>> 1);
                } 
                else 
                    i = k;
            }
        }
        System.out.println();

        int k = 1;
        for (int i = 1; i <= maxThreads;) {
            System.out.println("Threads:" + i);
            oneTest(i, maxIters, true);
            Thread.sleep(100);
            if (i == k) {
                k = i << 1;
                i = i + (i >>> 1);
            } 
            else 
                i = k;
        }
   }

    static void oneTest(int nThreads, int iters, boolean print) throws Exception {
        if (print) System.out.print("SynchronousQueue        ");
        oneRun(new SynchronousQueue<Runnable>(false), nThreads, iters, print);
        if (print) System.out.print("SynchronousQueue(fair)  ");
        oneRun(new SynchronousQueue<Runnable>(true), nThreads, iters, print);
    }

    static final class Task implements Runnable {
        final ThreadPoolExecutor pool;
        final CountDownLatch done;
        Task(ThreadPoolExecutor p, CountDownLatch d) { 
            pool = p; 
            done = d;
        }
        public void run() {
            done.countDown();
            remaining.incrementAndGet();
            int n;
            while (!Thread.interrupted() &&
                   (n = remaining.get()) > 0 && 
                   done.getCount() > 0) {
                if (remaining.compareAndSet(n, n-1)) {
                    try {
                        pool.execute(this);
                    }
                    catch (RuntimeException ex) {
                        System.out.print("*");
                        while (done.getCount() > 0) done.countDown();
                        return;
                    }
                }
            }
        }
    }
    
    static void oneRun(BlockingQueue<Runnable> q, int nThreads, int iters, boolean print) throws Exception {
       
        ThreadPoolExecutor pool = 
            new ThreadPoolExecutor(nThreads+1, Integer.MAX_VALUE,
                                   1L, TimeUnit.SECONDS, q);

        CountDownLatch done = new CountDownLatch(iters);
        remaining.set(nThreads-1);
        pool.prestartAllCoreThreads();
        Task t = new Task(pool, done);
        long start = System.nanoTime();
        pool.execute(t);
        done.await();
        long time = System.nanoTime() - start;
        if (print)
            System.out.println("\t: " + LoopHelpers.rightJustify(time / iters) + " ns per task");
        q.clear();
        Thread.sleep(100);
        pool.shutdown();
        Thread.sleep(100);
        pool.shutdownNow();
    }

}
Revision:	1.2
Committed:	Sun Aug 7 19:25:55 2005 UTC (18 years, 9 months ago) by dl
Branch:	MAIN
Changes since 1.1:	+32 -10 lines
Log Message:	Add exchanger performance tests; update others
#	User	Rev	Content
1	dl	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			import java.util.concurrent.*;
8			import java.util.concurrent.atomic.*;
9
10			public class CachedThreadPoolLoops {
11			static final AtomicInteger remaining = new AtomicInteger();
12			static final int maxIters = 1000000;
13
14			public static void main(String[] args) throws Exception {
15			int maxThreads = 100;
16
17			if (args.length > 0)
18			maxThreads = Integer.parseInt(args[0]);
19	dl	1.2
20			System.out.print("Warmup:");
21			for (int j = 0; j < 2; ++j) {
22			int k = 1;
23			for (int i = 1; i <= maxThreads;) {
24			System.out.print(" " + i);
25			oneTest(i, 10000, false);
26			Thread.sleep(100);
27			if (i == k) {
28			k = i << 1;
29			i = i + (i >>> 1);
30			}
31			else
32			i = k;
33			}
34			}
35			System.out.println();
36
37	dl	1.1	int k = 1;
38			for (int i = 1; i <= maxThreads;) {
39			System.out.println("Threads:" + i);
40	dl	1.2	oneTest(i, maxIters, true);
41	dl	1.1	Thread.sleep(100);
42			if (i == k) {
43			k = i << 1;
44			i = i + (i >>> 1);
45			}
46			else
47			i = k;
48			}
49			}
50
51	dl	1.2	static void oneTest(int nThreads, int iters, boolean print) throws Exception {
52			if (print) System.out.print("SynchronousQueue ");
53			oneRun(new SynchronousQueue<Runnable>(false), nThreads, iters, print);
54			if (print) System.out.print("SynchronousQueue(fair) ");
55			oneRun(new SynchronousQueue<Runnable>(true), nThreads, iters, print);
56	dl	1.1	}
57
58			static final class Task implements Runnable {
59			final ThreadPoolExecutor pool;
60			final CountDownLatch done;
61			Task(ThreadPoolExecutor p, CountDownLatch d) {
62			pool = p;
63			done = d;
64			}
65			public void run() {
66			done.countDown();
67			remaining.incrementAndGet();
68			int n;
69			while (!Thread.interrupted() &&
70			(n = remaining.get()) > 0 &&
71			done.getCount() > 0) {
72			if (remaining.compareAndSet(n, n-1)) {
73			try {
74			pool.execute(this);
75			}
76			catch (RuntimeException ex) {
77			System.out.print("*");
78			while (done.getCount() > 0) done.countDown();
79			return;
80			}
81			}
82			}
83			}
84			}
85
86	dl	1.2	static void oneRun(BlockingQueue<Runnable> q, int nThreads, int iters, boolean print) throws Exception {
87	dl	1.1
88			ThreadPoolExecutor pool =
89			new ThreadPoolExecutor(nThreads+1, Integer.MAX_VALUE,
90			1L, TimeUnit.SECONDS, q);
91
92	dl	1.2	CountDownLatch done = new CountDownLatch(iters);
93	dl	1.1	remaining.set(nThreads-1);
94			pool.prestartAllCoreThreads();
95			Task t = new Task(pool, done);
96			long start = System.nanoTime();
97			pool.execute(t);
98			done.await();
99			long time = System.nanoTime() - start;
100	dl	1.2	if (print)
101			System.out.println("\t: " + LoopHelpers.rightJustify(time / iters) + " ns per task");
102			q.clear();
103			Thread.sleep(100);
104			pool.shutdown();
105			Thread.sleep(100);
106	dl	1.1	pool.shutdownNow();
107			}
108
109			}