test/loops/CachedThreadPoolLoops.java

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

//import jsr166y.*;
import java.util.concurrent.*;
import java.util.concurrent.atomic.*;

public class CachedThreadPoolLoops {
    static final int NCPUS = Runtime.getRuntime().availableProcessors();
    static final AtomicInteger remaining = new AtomicInteger();
    static final int maxIters = 1000000;

    public static void main(String[] args) throws Exception {
        int maxThreads = NCPUS * 3 / 2; // 100;
        if (args.length > 0)
            maxThreads = Integer.parseInt(args[0]);

        System.out.print("Warmup:");
        for (int j = 0; j < 1; ++j) {
            for (int k = 1, 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();

        for (int k = 1, 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 {
        Thread.sleep(100); // System.gc();
        if (print) System.out.print("LinkedTransferQueue      ");
        oneRun(new LinkedTransferQueue<Runnable>(), nThreads, iters, print);

        Thread.sleep(100); // System.gc();
        if (print) System.out.print("LinkedBlockingQueue      ");
        oneRun(new LinkedBlockingQueue<Runnable>(), nThreads, iters, print);

        Thread.sleep(100); // System.gc();
        if (print) System.out.print("SynchronousQueue         ");
        oneRun(new SynchronousQueue<Runnable>(false), nThreads, iters, print);

        Thread.sleep(100); // System.gc();
        if (print) System.out.print("SynchronousQueue(fair)   ");
        oneRun(new SynchronousQueue<Runnable>(true), nThreads, iters, print);

        Thread.sleep(100); // System.gc();
        if (print) System.out.print("LinkedTransferQueue(xfer)");
        oneRun(new LTQasSQ<Runnable>(), nThreads, iters, print);

        Thread.sleep(100); // System.gc();
        if (print) System.out.print("LinkedTransferQueue(half)");
        oneRun(new HalfSyncLTQ<Runnable>(), nThreads, iters, print);

        Thread.sleep(100); // System.gc();
        if (print) System.out.print("ArrayBlockingQueue(256) ");
        oneRun(new ArrayBlockingQueue<Runnable>(256), 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();
    }

    static final class LTQasSQ<T> extends LinkedTransferQueue<T> {
        LTQasSQ() { super(); }
        public void put(T x) {
            try { super.transfer(x);
            } catch (InterruptedException ex) { throw new Error(); }
        }
    }

    static final class HalfSyncLTQ<T> extends LinkedTransferQueue<T> {
        int calls;
        HalfSyncLTQ() { super(); }
        public void put(T x) {
            if ((++calls & 1) == 0)
                super.put(x);
            else {
                try { super.transfer(x);
                } catch (InterruptedException ex) {
                    throw new Error();
                }
            }
        }
    }

}
Revision:	1.8
Committed:	Thu Dec 18 18:13:06 2014 UTC (9 years, 5 months ago) by jsr166
Branch:	MAIN
Changes since 1.7:	+2 -4 lines
Log Message:	move k = 1 into loop initializer
#	Content
1	/*
2	* Written by Doug Lea with assistance from members of JCP JSR-166
3	* Expert Group and released to the public domain, as explained at
4	* http://creativecommons.org/publicdomain/zero/1.0/
5	*/
6
7	//import jsr166y.*;
8	import java.util.concurrent.*;
9	import java.util.concurrent.atomic.*;
10
11	public class CachedThreadPoolLoops {
12	static final int NCPUS = Runtime.getRuntime().availableProcessors();
13	static final AtomicInteger remaining = new AtomicInteger();
14	static final int maxIters = 1000000;
15
16	public static void main(String[] args) throws Exception {
17	int maxThreads = NCPUS * 3 / 2; // 100;
18	if (args.length > 0)
19	maxThreads = Integer.parseInt(args[0]);
20
21	System.out.print("Warmup:");
22	for (int j = 0; j < 1; ++j) {
23	for (int k = 1, 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	for (int k = 1, i = 1; i <= maxThreads;) {
38	System.out.println("Threads:" + i);
39	oneTest(i, maxIters, true);
40	Thread.sleep(100);
41	if (i == k) {
42	k = i << 1;
43	i = i + (i >>> 1);
44	}
45	else
46	i = k;
47	}
48	}
49
50	static void oneTest(int nThreads, int iters, boolean print) throws Exception {
51	Thread.sleep(100); // System.gc();
52	if (print) System.out.print("LinkedTransferQueue ");
53	oneRun(new LinkedTransferQueue<Runnable>(), nThreads, iters, print);
54
55	Thread.sleep(100); // System.gc();
56	if (print) System.out.print("LinkedBlockingQueue ");
57	oneRun(new LinkedBlockingQueue<Runnable>(), nThreads, iters, print);
58
59	Thread.sleep(100); // System.gc();
60	if (print) System.out.print("SynchronousQueue ");
61	oneRun(new SynchronousQueue<Runnable>(false), nThreads, iters, print);
62
63	Thread.sleep(100); // System.gc();
64	if (print) System.out.print("SynchronousQueue(fair) ");
65	oneRun(new SynchronousQueue<Runnable>(true), nThreads, iters, print);
66
67	Thread.sleep(100); // System.gc();
68	if (print) System.out.print("LinkedTransferQueue(xfer)");
69	oneRun(new LTQasSQ<Runnable>(), nThreads, iters, print);
70
71	Thread.sleep(100); // System.gc();
72	if (print) System.out.print("LinkedTransferQueue(half)");
73	oneRun(new HalfSyncLTQ<Runnable>(), nThreads, iters, print);
74
75	Thread.sleep(100); // System.gc();
76	if (print) System.out.print("ArrayBlockingQueue(256) ");
77	oneRun(new ArrayBlockingQueue<Runnable>(256), nThreads, iters, print);
78
79	}
80
81	static final class Task implements Runnable {
82	final ThreadPoolExecutor pool;
83	final CountDownLatch done;
84	Task(ThreadPoolExecutor p, CountDownLatch d) {
85	pool = p;
86	done = d;
87	}
88	public void run() {
89	done.countDown();
90	remaining.incrementAndGet();
91	int n;
92	while (!Thread.interrupted() &&
93	(n = remaining.get()) > 0 &&
94	done.getCount() > 0) {
95	if (remaining.compareAndSet(n, n-1)) {
96	try {
97	pool.execute(this);
98	}
99	catch (RuntimeException ex) {
100	System.out.print("*");
101	while (done.getCount() > 0) done.countDown();
102	return;
103	}
104	}
105	}
106	}
107	}
108
109	static void oneRun(BlockingQueue<Runnable> q, int nThreads, int iters, boolean print) throws Exception {
110
111	ThreadPoolExecutor pool =
112	new ThreadPoolExecutor(nThreads+1, Integer.MAX_VALUE,
113	1L, TimeUnit.SECONDS, q);
114
115	CountDownLatch done = new CountDownLatch(iters);
116	remaining.set(nThreads-1);
117	pool.prestartAllCoreThreads();
118	Task t = new Task(pool, done);
119	long start = System.nanoTime();
120	pool.execute(t);
121	done.await();
122	long time = System.nanoTime() - start;
123	if (print)
124	System.out.println("\t: " + LoopHelpers.rightJustify(time / iters) + " ns per task");
125	q.clear();
126	Thread.sleep(100);
127	pool.shutdown();
128	Thread.sleep(100);
129	pool.shutdownNow();
130	}
131
132	static final class LTQasSQ<T> extends LinkedTransferQueue<T> {
133	LTQasSQ() { super(); }
134	public void put(T x) {
135	try { super.transfer(x);
136	} catch (InterruptedException ex) { throw new Error(); }
137	}
138	}
139
140	static final class HalfSyncLTQ<T> extends LinkedTransferQueue<T> {
141	int calls;
142	HalfSyncLTQ() { super(); }
143	public void put(T x) {
144	if ((++calls & 1) == 0)
145	super.put(x);
146	else {
147	try { super.transfer(x);
148	} catch (InterruptedException ex) {
149	throw new Error();
150	}
151	}
152	}
153	}
154
155	}