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:	1.4
Committed:	Mon Feb 19 00:46:06 2007 UTC (17 years, 3 months ago) by dl
Branch:	MAIN
Changes since 1.3:	+2 -3 lines
Log Message:	Uniform headers
#	Content
1	/*
2	* Written by Bill Scherer and Doug Lea with assistance from members
3	* of JCP JSR-166 Expert Group and released to the public domain, as
4	* explained at http://creativecommons.org/licenses/publicdomain
5	*/
6
7	import java.util.concurrent.*;
8	import java.util.concurrent.atomic.*;
9	import java.util.concurrent.locks.*;
10
11	public class ExchangeLoops {
12	static final int NCPUS = Runtime.getRuntime().availableProcessors();
13
14	static final int DEFAULT_THREADS = NCPUS + 2;
15	static final long DEFAULT_TRIAL_MILLIS = 10000;
16
17	public static void main(String[] args) throws Exception {
18	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	else
31	maxThreads = Integer.parseInt(option);
32	argc++;
33	}
34
35	// 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
55	/*
56	for (int i = maxThreads; i >= 2; i -= 1) {
57	oneRun(i, warmupTime++);
58	}
59	*/
60
61	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	}
68	for (int i = maxThreads; i >= 2; i -= 2) {
69	oneRun(i, trialMillis);
70	// System.gc();
71	Thread.sleep(sleepTime);
72	}
73	Thread.sleep(sleepTime);
74	}
75
76
77	}
78
79	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	for (int i = 0; i < nThreads; ++i)
100	threads[i].interrupt();
101	long elapsed = System.nanoTime() - startTime;
102	for (int i = 0; i < nThreads; ++i)
103	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	System.out.printf("%9dms", elapsed / (1000L * 1000L));
114	System.out.printf("%9d it/s ", rate);
115	System.out.printf("%9d ns/it", npt);
116	System.out.println();
117	// x.printStats();
118	}
119
120	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
126	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	}
144