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.ArrayList;
import java.util.Deque;
import java.util.concurrent.Callable;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.atomic.AtomicInteger;

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.getConstructor().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:	1.14
Committed:	Sat Dec 31 19:02:43 2016 UTC (7 years, 4 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.13:	+8 -4 lines
Log Message:	organize imports
#	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	jsr166	1.14	import java.util.ArrayList;
8			import java.util.Deque;
9			import java.util.concurrent.Callable;
10			import java.util.concurrent.CyclicBarrier;
11			import java.util.concurrent.ExecutorService;
12			import java.util.concurrent.Executors;
13			import java.util.concurrent.Future;
14			import java.util.concurrent.atomic.AtomicInteger;
15	dl	1.1
16			public class ConcurrentDequeLoops {
17			static final ExecutorService pool = Executors.newCachedThreadPool();
18			static AtomicInteger totalItems;
19			static boolean print = false;
20
21			public static void main(String[] args) throws Exception {
22			int maxStages = 8;
23			int items = 1000000;
24
25	jsr166	1.11	Class<?> klass = null;
26	dl	1.1	if (args.length > 0) {
27			try {
28			klass = Class.forName(args[0]);
29	jsr166	1.4	} catch (ClassNotFoundException e) {
30	dl	1.1	throw new RuntimeException("Class " + args[0] + " not found.");
31			}
32			}
33	jsr166	1.3	else
34	dl	1.1	throw new Error();
35
36	jsr166	1.3	if (args.length > 1)
37	dl	1.1	maxStages = Integer.parseInt(args[1]);
38
39			System.out.print("Class: " + klass.getName());
40			System.out.println(" stages: " + maxStages);
41
42			print = false;
43			System.out.println("Warmup...");
44			oneRun(klass, 1, items);
45			Thread.sleep(100);
46			oneRun(klass, 1, items);
47			Thread.sleep(100);
48			print = true;
49
50	jsr166	1.10	for (int k = 1, i = 1; i <= maxStages;) {
51	dl	1.1	oneRun(klass, i, items);
52			if (i == k) {
53			k = i << 1;
54			i = i + (i >>> 1);
55	jsr166	1.3	}
56			else
57	dl	1.1	i = k;
58			}
59			pool.shutdown();
60	jsr166	1.9	}
61	dl	1.1
62			static class Stage implements Callable<Integer> {
63			final Deque<Integer> queue;
64			final CyclicBarrier barrier;
65			final LoopHelpers.SimpleRandom rng = new LoopHelpers.SimpleRandom();
66			int items;
67	jsr166	1.7	Stage(Deque<Integer> q, CyclicBarrier b, int items) {
68	jsr166	1.3	queue = q;
69	dl	1.1	barrier = b;
70			this.items = items;
71			}
72
73			public Integer call() {
74			// Repeatedly take something from queue if possible,
75			// transform it, and put back in.
76			try {
77			barrier.await();
78	jsr166	1.6	int l = (int) System.nanoTime();
79	dl	1.1	int takes = 0;
80			for (;;) {
81			Integer item;
82			int rnd = rng.next();
83			if ((rnd & 1) == 0)
84			item = queue.pollFirst();
85			else
86			item = queue.pollLast();
87			if (item != null) {
88			++takes;
89			l += LoopHelpers.compute2(item.intValue());
90			}
91			else if (takes != 0) {
92			totalItems.getAndAdd(-takes);
93			takes = 0;
94			}
95			else if (totalItems.get() <= 0)
96			break;
97			l = LoopHelpers.compute1(l);
98			if (items > 0) {
99			--items;
100			Integer res = new Integer(l);
101			if ((rnd & 16) == 0)
102			queue.addFirst(res);
103			else
104			queue.addLast(res);
105			}
106	jsr166	1.3	else { // spinwait
107	dl	1.1	for (int k = 1 + (l & 15); k != 0; --k)
108			l = LoopHelpers.compute1(LoopHelpers.compute2(l));
109			if ((l & 3) == 3) {
110			Thread.sleep(1);
111			}
112			}
113			}
114			return new Integer(l);
115			}
116	jsr166	1.3	catch (Exception ie) {
117	dl	1.1	ie.printStackTrace();
118			throw new Error("Call loop failed");
119			}
120			}
121			}
122
123	jsr166	1.11	static void oneRun(Class<?> klass, int n, int items) throws Exception {
124	jsr166	1.13	Deque<Integer> q =
125			(Deque<Integer>) klass.getConstructor().newInstance();
126	dl	1.1	LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
127			CyclicBarrier barrier = new CyclicBarrier(n + 1, timer);
128			totalItems = new AtomicInteger(n * items);
129			ArrayList<Future<Integer>> results = new ArrayList<Future<Integer>>(n);
130	jsr166	1.3	for (int i = 0; i < n; ++i)
131	dl	1.1	results.add(pool.submit(new Stage(q, barrier, items)));
132
133			if (print)
134			System.out.print("Threads: " + n + "\t:");
135			barrier.await();
136			int total = 0;
137			for (int i = 0; i < n; ++i) {
138			Future<Integer> f = results.get(i);
139			Integer r = f.get();
140			total += r.intValue();
141			}
142			long endTime = System.nanoTime();
143			long time = endTime - timer.startTime;
144			if (print)
145			System.out.println(LoopHelpers.rightJustify(time / (items * n)) + " ns per item");
146			if (total == 0) // avoid overoptimization
147			System.out.println("useless result: " + total);
148			}
149			}