test/loops/ConcurrentDequeLoops.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 java.util.*;
import java.util.concurrent.*;
import java.util.concurrent.atomic.*;
import java.util.concurrent.locks.*;

public class ConcurrentDequeLoops {
    static final ExecutorService pool = Executors.newCachedThreadPool();
    static AtomicInteger totalItems;
    static boolean print = false;

    public static void main(String[] args) throws Exception {
        int maxStages = 8;
        int items = 1000000;

        Class klass = null;
        if (args.length > 0) {
            try {
                klass = Class.forName(args[0]);
            } catch (ClassNotFoundException e) {
                throw new RuntimeException("Class " + args[0] + " not found.");
            }
        }
        else
            throw new Error();

        if (args.length > 1)
            maxStages = Integer.parseInt(args[1]);

        System.out.print("Class: " + klass.getName());
        System.out.println(" stages: " + maxStages);

        print = false;
        System.out.println("Warmup...");
        oneRun(klass, 1, items);
        Thread.sleep(100);
        oneRun(klass, 1, items);
        Thread.sleep(100);
        print = true;

        for (int k = 1, i = 1; i <= maxStages;) {
            oneRun(klass, i, items);
            if (i == k) {
                k = i << 1;
                i = i + (i >>> 1);
            }
            else
                i = k;
        }
        pool.shutdown();
    }

    static class Stage implements Callable<Integer> {
        final Deque<Integer> queue;
        final CyclicBarrier barrier;
        final LoopHelpers.SimpleRandom rng = new LoopHelpers.SimpleRandom();
        int items;
        Stage(Deque<Integer> q, CyclicBarrier b, int items) {
            queue = q;
            barrier = b;
            this.items = items;
        }

        public Integer call() {
            // Repeatedly take something from queue if possible,
            // transform it, and put back in.
            try {
                barrier.await();
                int l = (int) System.nanoTime();
                int takes = 0;
                for (;;) {
                    Integer item;
                    int rnd = rng.next();
                    if ((rnd & 1) == 0)
                        item = queue.pollFirst();
                    else
                        item = queue.pollLast();
                    if (item != null) {
                        ++takes;
                        l += LoopHelpers.compute2(item.intValue());
                    }
                    else if (takes != 0) {
                        totalItems.getAndAdd(-takes);
                        takes = 0;
                    }
                    else if (totalItems.get() <= 0)
                        break;
                    l = LoopHelpers.compute1(l);
                    if (items > 0) {
                        --items;
                        Integer res = new Integer(l);
                        if ((rnd & 16) == 0)
                            queue.addFirst(res);
                        else
                            queue.addLast(res);
                    }
                    else { // spinwait
                        for (int k = 1 + (l & 15); k != 0; --k)
                            l = LoopHelpers.compute1(LoopHelpers.compute2(l));
                        if ((l & 3) == 3) {
                            Thread.sleep(1);
                        }
                    }
                }
                return new Integer(l);
            }
            catch (Exception ie) {
                ie.printStackTrace();
                throw new Error("Call loop failed");
            }
        }
    }

    static void oneRun(Class klass, int n, int items) throws Exception {
        Deque<Integer> q = (Deque<Integer>) klass.newInstance();
        LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
        CyclicBarrier barrier = new CyclicBarrier(n + 1, timer);
        totalItems = new AtomicInteger(n * items);
        ArrayList<Future<Integer>> results = new ArrayList<Future<Integer>>(n);
        for (int i = 0; i < n; ++i)
            results.add(pool.submit(new Stage(q, barrier, items)));

        if (print)
            System.out.print("Threads: " + n + "\t:");
        barrier.await();
        int total = 0;
        for (int i = 0; i < n; ++i) {
            Future<Integer> f = results.get(i);
            Integer r = f.get();
            total += r.intValue();
        }
        long endTime = System.nanoTime();
        long time = endTime - timer.startTime;
        if (print)
            System.out.println(LoopHelpers.rightJustify(time / (items * n)) + " ns per item");
        if (total == 0) // avoid overoptimization
            System.out.println("useless result: " + total);

    }
}
Revision:	1.10
Committed:	Thu Dec 18 18:13:06 2014 UTC (9 years, 5 months ago) by jsr166
Branch:	MAIN
Changes since 1.9:	+1 -2 lines
Log Message:	move k = 1 into loop initializer
#	User	Rev	Content
1	dl	1.1	/*
2			* Written by Doug Lea with assistance from members of JCP JSR-166
3	dl	1.2	* Expert Group and released to the public domain, as explained at
4	jsr166	1.8	* http://creativecommons.org/publicdomain/zero/1.0/
5	dl	1.1	*/
6
7			import java.util.*;
8			import java.util.concurrent.*;
9			import java.util.concurrent.atomic.*;
10			import java.util.concurrent.locks.*;
11
12			public class ConcurrentDequeLoops {
13			static final ExecutorService pool = Executors.newCachedThreadPool();
14			static AtomicInteger totalItems;
15			static boolean print = false;
16
17			public static void main(String[] args) throws Exception {
18			int maxStages = 8;
19			int items = 1000000;
20
21			Class klass = null;
22			if (args.length > 0) {
23			try {
24			klass = Class.forName(args[0]);
25	jsr166	1.4	} catch (ClassNotFoundException e) {
26	dl	1.1	throw new RuntimeException("Class " + args[0] + " not found.");
27			}
28			}
29	jsr166	1.3	else
30	dl	1.1	throw new Error();
31
32	jsr166	1.3	if (args.length > 1)
33	dl	1.1	maxStages = Integer.parseInt(args[1]);
34
35			System.out.print("Class: " + klass.getName());
36			System.out.println(" stages: " + maxStages);
37
38			print = false;
39			System.out.println("Warmup...");
40			oneRun(klass, 1, items);
41			Thread.sleep(100);
42			oneRun(klass, 1, items);
43			Thread.sleep(100);
44			print = true;
45
46	jsr166	1.10	for (int k = 1, i = 1; i <= maxStages;) {
47	dl	1.1	oneRun(klass, i, items);
48			if (i == k) {
49			k = i << 1;
50			i = i + (i >>> 1);
51	jsr166	1.3	}
52			else
53	dl	1.1	i = k;
54			}
55			pool.shutdown();
56	jsr166	1.9	}
57	dl	1.1
58			static class Stage implements Callable<Integer> {
59			final Deque<Integer> queue;
60			final CyclicBarrier barrier;
61			final LoopHelpers.SimpleRandom rng = new LoopHelpers.SimpleRandom();
62			int items;
63	jsr166	1.7	Stage(Deque<Integer> q, CyclicBarrier b, int items) {
64	jsr166	1.3	queue = q;
65	dl	1.1	barrier = b;
66			this.items = items;
67			}
68
69			public Integer call() {
70			// Repeatedly take something from queue if possible,
71			// transform it, and put back in.
72			try {
73			barrier.await();
74	jsr166	1.6	int l = (int) System.nanoTime();
75	dl	1.1	int takes = 0;
76			for (;;) {
77			Integer item;
78			int rnd = rng.next();
79			if ((rnd & 1) == 0)
80			item = queue.pollFirst();
81			else
82			item = queue.pollLast();
83			if (item != null) {
84			++takes;
85			l += LoopHelpers.compute2(item.intValue());
86			}
87			else if (takes != 0) {
88			totalItems.getAndAdd(-takes);
89			takes = 0;
90			}
91			else if (totalItems.get() <= 0)
92			break;
93			l = LoopHelpers.compute1(l);
94			if (items > 0) {
95			--items;
96			Integer res = new Integer(l);
97			if ((rnd & 16) == 0)
98			queue.addFirst(res);
99			else
100			queue.addLast(res);
101			}
102	jsr166	1.3	else { // spinwait
103	dl	1.1	for (int k = 1 + (l & 15); k != 0; --k)
104			l = LoopHelpers.compute1(LoopHelpers.compute2(l));
105			if ((l & 3) == 3) {
106			Thread.sleep(1);
107			}
108			}
109			}
110			return new Integer(l);
111			}
112	jsr166	1.3	catch (Exception ie) {
113	dl	1.1	ie.printStackTrace();
114			throw new Error("Call loop failed");
115			}
116			}
117			}
118
119			static void oneRun(Class klass, int n, int items) throws Exception {
120	jsr166	1.5	Deque<Integer> q = (Deque<Integer>) klass.newInstance();
121	dl	1.1	LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
122			CyclicBarrier barrier = new CyclicBarrier(n + 1, timer);
123			totalItems = new AtomicInteger(n * items);
124			ArrayList<Future<Integer>> results = new ArrayList<Future<Integer>>(n);
125	jsr166	1.3	for (int i = 0; i < n; ++i)
126	dl	1.1	results.add(pool.submit(new Stage(q, barrier, items)));
127
128			if (print)
129			System.out.print("Threads: " + n + "\t:");
130			barrier.await();
131			int total = 0;
132			for (int i = 0; i < n; ++i) {
133			Future<Integer> f = results.get(i);
134			Integer r = f.get();
135			total += r.intValue();
136			}
137			long endTime = System.nanoTime();
138			long time = endTime - timer.startTime;
139			if (print)
140			System.out.println(LoopHelpers.rightJustify(time / (items * n)) + " ns per item");
141			if (total == 0) // avoid overoptimization
142			System.out.println("useless result: " + total);
143	jsr166	1.3
144	dl	1.1	}
145			}