test/loops/ExchangeLoops.java

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

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

public class ExchangeLoops {
    static final int NCPUS = Runtime.getRuntime().availableProcessors();

    static final int  DEFAULT_THREADS = NCPUS + 2;
    static final long DEFAULT_TRIAL_MILLIS   = 10000;

    public static void main(String[] args) throws Exception {
        int maxThreads = DEFAULT_THREADS;
        long trialMillis = DEFAULT_TRIAL_MILLIS;
        int nReps = 3;

        // Parse and check args
        int argc = 0;
        while (argc < args.length) {
            String option = args[argc++];
            if (option.equals("-t"))
                trialMillis = Integer.parseInt(args[argc]);
            else if (option.equals("-r"))
                nReps = Integer.parseInt(args[argc]);
            else
                maxThreads = Integer.parseInt(option);
            argc++;
        }

        // Display runtime parameters
        System.out.print("ExchangeTest");
        System.out.print(" -t " + trialMillis);
        System.out.print(" -r " + nReps);
        System.out.print(" max threads " + maxThreads);
        System.out.println();
        long warmupTime = 2000;
        long sleepTime = 100;
        int nw = maxThreads >= 3? 3 : 2;

        System.out.println("Warmups..");
        oneRun(3, warmupTime);
        Thread.sleep(sleepTime);

        for (int i = maxThreads; i >= 2; i -= 1) {
            oneRun(i, warmupTime++);
            //            System.gc();
            Thread.sleep(sleepTime);
        }

        /*
        for (int i = maxThreads; i >= 2; i -= 1) {
            oneRun(i, warmupTime++);
        }
        */

        for (int j = 0; j < nReps; ++j) {
            System.out.println("Trial: " + j);
            for (int i = 2; i <= maxThreads; i += 2) {
                oneRun(i, trialMillis);
                //                System.gc();
                Thread.sleep(sleepTime);
            }
            for (int i = maxThreads; i >= 2; i -= 2) {
                oneRun(i, trialMillis);
                //                System.gc();
                Thread.sleep(sleepTime);
            }
            Thread.sleep(sleepTime);
        }


    }

    static void oneRun(int nThreads, long trialMillis) throws Exception {
        System.out.printf("%4d threads", nThreads);
        Exchanger x = new Exchanger();
        Runner[] runners = new Runner[nThreads];
        Thread[] threads = new Thread[nThreads];
        for (int i = 0; i < nThreads; ++i) {
            runners[i] = new Runner(x);
            threads[i] = new Thread(runners[i]);
            //            int h = System.identityHashCode(threads[i]);
            //            h ^= h << 1;
            //            h ^= h >>> 3;
            //            h ^= h << 10;
            //            System.out.printf("%10x\n", h);
        }

        long startTime = System.nanoTime();
        for (int i = 0; i < nThreads; ++i) {
            threads[i].start();
        }
        Thread.sleep(trialMillis);
        for (int i = 0; i < nThreads; ++i)
            threads[i].interrupt();
        long elapsed = System.nanoTime() - startTime;
        for (int i = 0; i < nThreads; ++i)
            threads[i].join();
        int iters = 1;
        //        System.out.println();
        for (int i = 0; i < nThreads; ++i) {
            int ipr = runners[i].iters;
            //            System.out.println(ipr);
            iters += ipr;
        }
        long rate = iters * 1000L * 1000L * 1000L / elapsed;
        long npt = elapsed / iters;
        System.out.printf("%9dms", elapsed / (1000L * 1000L));
        System.out.printf("%9d it/s ", rate);
        System.out.printf("%9d ns/it", npt);
        System.out.println();
        //        x.printStats();
    }

    static final class Runner implements Runnable {
        final Exchanger exchanger;
        final Object mine = new Integer(2688);
        volatile int iters;
        Runner(Exchanger x) { this.exchanger = x; }

        public void run() {
            Exchanger x = exchanger;
            Object m = mine;
            int i = 0;
            try {
                for (;;) {
                    Object e = x.exchange(m);
                    if (e == null || e == m)
                        throw new Error();
                    m = e;
                    ++i;
                }
            } catch (InterruptedException ie) {
                iters = i;
            }
        }
    }
}
Revision:	1.5
Committed:	Thu Oct 29 23:09:07 2009 UTC (14 years, 6 months ago) by jsr166
Branch:	MAIN
Changes since 1.4:	+4 -5 lines
Log Message:	whitespace
#	User	Rev	Content
1	dl	1.1	/*
2	dl	1.2	* Written by Bill Scherer and Doug Lea with assistance from members
3	dl	1.4	* of JCP JSR-166 Expert Group and released to the public domain, as
4			* explained at http://creativecommons.org/licenses/publicdomain
5	dl	1.1	*/
6
7			import java.util.concurrent.*;
8	dl	1.2	import java.util.concurrent.atomic.*;
9			import java.util.concurrent.locks.*;
10	dl	1.1
11			public class ExchangeLoops {
12	dl	1.2	static final int NCPUS = Runtime.getRuntime().availableProcessors();
13	dl	1.1
14	dl	1.2	static final int DEFAULT_THREADS = NCPUS + 2;
15			static final long DEFAULT_TRIAL_MILLIS = 10000;
16	dl	1.1
17			public static void main(String[] args) throws Exception {
18	dl	1.2	int maxThreads = DEFAULT_THREADS;
19			long trialMillis = DEFAULT_TRIAL_MILLIS;
20			int nReps = 3;
21
22			// Parse and check args
23			int argc = 0;
24			while (argc < args.length) {
25			String option = args[argc++];
26			if (option.equals("-t"))
27			trialMillis = Integer.parseInt(args[argc]);
28			else if (option.equals("-r"))
29			nReps = Integer.parseInt(args[argc]);
30	jsr166	1.5	else
31	dl	1.2	maxThreads = Integer.parseInt(option);
32			argc++;
33			}
34	dl	1.1
35	dl	1.2	// Display runtime parameters
36			System.out.print("ExchangeTest");
37			System.out.print(" -t " + trialMillis);
38			System.out.print(" -r " + nReps);
39			System.out.print(" max threads " + maxThreads);
40			System.out.println();
41			long warmupTime = 2000;
42			long sleepTime = 100;
43			int nw = maxThreads >= 3? 3 : 2;
44
45			System.out.println("Warmups..");
46			oneRun(3, warmupTime);
47			Thread.sleep(sleepTime);
48
49			for (int i = maxThreads; i >= 2; i -= 1) {
50			oneRun(i, warmupTime++);
51			// System.gc();
52			Thread.sleep(sleepTime);
53			}
54	dl	1.1
55	dl	1.2	/*
56			for (int i = maxThreads; i >= 2; i -= 1) {
57			oneRun(i, warmupTime++);
58	dl	1.1	}
59	dl	1.2	*/
60	dl	1.1
61	dl	1.2	for (int j = 0; j < nReps; ++j) {
62			System.out.println("Trial: " + j);
63			for (int i = 2; i <= maxThreads; i += 2) {
64			oneRun(i, trialMillis);
65			// System.gc();
66			Thread.sleep(sleepTime);
67	dl	1.1	}
68	dl	1.2	for (int i = maxThreads; i >= 2; i -= 2) {
69			oneRun(i, trialMillis);
70			// System.gc();
71			Thread.sleep(sleepTime);
72	dl	1.1	}
73	dl	1.2	Thread.sleep(sleepTime);
74	dl	1.1	}
75	dl	1.2
76
77	dl	1.1	}
78
79	dl	1.2	static void oneRun(int nThreads, long trialMillis) throws Exception {
80			System.out.printf("%4d threads", nThreads);
81			Exchanger x = new Exchanger();
82			Runner[] runners = new Runner[nThreads];
83			Thread[] threads = new Thread[nThreads];
84			for (int i = 0; i < nThreads; ++i) {
85			runners[i] = new Runner(x);
86			threads[i] = new Thread(runners[i]);
87			// int h = System.identityHashCode(threads[i]);
88			// h ^= h << 1;
89			// h ^= h >>> 3;
90			// h ^= h << 10;
91			// System.out.printf("%10x\n", h);
92			}
93
94			long startTime = System.nanoTime();
95			for (int i = 0; i < nThreads; ++i) {
96			threads[i].start();
97			}
98			Thread.sleep(trialMillis);
99	jsr166	1.5	for (int i = 0; i < nThreads; ++i)
100	dl	1.2	threads[i].interrupt();
101			long elapsed = System.nanoTime() - startTime;
102	jsr166	1.5	for (int i = 0; i < nThreads; ++i)
103	dl	1.2	threads[i].join();
104			int iters = 1;
105			// System.out.println();
106			for (int i = 0; i < nThreads; ++i) {
107			int ipr = runners[i].iters;
108			// System.out.println(ipr);
109			iters += ipr;
110			}
111			long rate = iters * 1000L * 1000L * 1000L / elapsed;
112			long npt = elapsed / iters;
113	dl	1.3	System.out.printf("%9dms", elapsed / (1000L * 1000L));
114	dl	1.2	System.out.printf("%9d it/s ", rate);
115			System.out.printf("%9d ns/it", npt);
116			System.out.println();
117			// x.printStats();
118	dl	1.1	}
119	jsr166	1.5
120	dl	1.2	static final class Runner implements Runnable {
121			final Exchanger exchanger;
122			final Object mine = new Integer(2688);
123			volatile int iters;
124			Runner(Exchanger x) { this.exchanger = x; }
125	dl	1.1
126	dl	1.2	public void run() {
127			Exchanger x = exchanger;
128			Object m = mine;
129			int i = 0;
130			try {
131			for (;;) {
132			Object e = x.exchange(m);
133			if (e == null \|\| e == m)
134			throw new Error();
135			m = e;
136			++i;
137			}
138			} catch (InterruptedException ie) {
139			iters = i;
140			}
141			}
142			}
143	dl	1.1	}