test/extra166y/FilterDemo.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/licenses/publicdomain
 */

import jsr166y.*;
import extra166y.*;
import java.util.*;
import java.util.concurrent.*;


public class FilterDemo {
    static final int NCPU = Runtime.getRuntime().availableProcessors();

    /**
     * Sequential version, for performance comparison
     */
    static<T> List<T> seqFilter(T[] list,
                                Ops.Predicate<T> pred) {
        ArrayList<T> result = new ArrayList<T>();
        int n = list.length;
        for (int i = 0; i < n; ++i) {
            T x = list[i];
            if (pred.op(x))
                result.add(x);
        }
        return result;
    }

    /**
     * Slow/dumb prime check
     */
    static final class IsPrime implements Ops.Predicate<Rand> {
        public boolean op(Rand r) {
            long n = r.seed;
            if ((n & 1) == 0)
                return false;
            int bound = (int)(Math.sqrt(n));
            for (int i = 3; i <= bound; i += 2)
                if (n % i == 0)
                    return false;
            return true;
        }
    }

    /** for time conversion */
    static final long NPS = (1000L * 1000 * 1000);

    static final class NextRand implements Ops.Procedure<Rand> {
        public void op(Rand r) {
            r.next();
        }
    }

    public static void main(String[] args) throws Exception {
        int n = 1 << 9;
        Rand[] array = new Rand[n];
        for (int i = 0; i < n; ++i)
            array[i] = new Rand(i);
        final IsPrime pred = new IsPrime();
        final NextRand nextRand = new NextRand();
        long last, now;
        double elapsed;
        last = System.nanoTime();
        List<Rand> seqResult = null;
        int resultLength = -1;
        boolean checked = false;
        for (int k = 0; k < 2; ++k) {
            List<Rand> result = seqFilter(array, pred);
            now = System.nanoTime();
            if (resultLength < 0) {
                resultLength = result.size();
                seqResult = result;
            }
            else if (resultLength != result.size())
                throw new Error("wrong result size");
            elapsed = (double)(now - last) / NPS;
            last = now;
            System.out.printf("seq:    %7.3f\n", elapsed);
            //            for (Rand r : array) r.next();
        }
        int pass = 0;
        int ps = 2;
        ForkJoinPool fjp = new ForkJoinPool(ps);
        ParallelArray<Rand> pa = ParallelArray.createUsingHandoff(array, fjp);
        for (;;) {
            last = System.nanoTime();
            for (int k = 0; k < 4; ++k) {
                List<Rand> result = pa.withFilter(pred).all().asList();
                now = System.nanoTime();
                if (!checked) {
                    checked = true;
                    if (!result.equals(seqResult))
                        throw new Error("res" + result + " seq" + seqResult);
                }
                elapsed = (double)(now - last) / NPS;
                last = now;
                System.out.printf("ps %2d:  %7.3f\n", ps, elapsed);
            }
            if (pass == 0) {
                if (ps >= NCPU)
                    pass = 1;
                else
                    ps <<= 1;
            }
            else {
                if (ps == 1)
                    break;
                else
                    ps >>>= 1;
            }
            //            pa.apply(nextRand);
            fjp.setParallelism(ps);
        }
        fjp.shutdownNow();
        fjp.awaitTermination(1, TimeUnit.SECONDS);
    }

    /**
     * Unsynchronized version of java.util.Random algorithm.
     */
    static final class Rand {
        private static final long multiplier = 0x5DEECE66DL;
        private static final long addend = 0xBL;
        private static final long mask = (1L << 48) - 1;
        private long seed;

        Rand(long s) {
            seed = s;
            next();
            next();
        }
        public int next() {
            long nextseed = (seed * multiplier + addend) & mask;
            seed = nextseed;
            return ((int)(nextseed >>> 17)) & 0x7FFFFFFF;
        }

        public String toString() {
            return String.valueOf(seed);
        }
    }

}
Revision:	1.3
Committed:	Mon Sep 27 19:15:15 2010 UTC (13 years, 7 months ago) by jsr166
Branch:	MAIN
Changes since 1.2:	+3 -3 lines
Log Message:	use blessed declaration modifier order
#	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/licenses/publicdomain
5	*/
6
7	import jsr166y.*;
8	import extra166y.*;
9	import java.util.*;
10	import java.util.concurrent.*;
11
12
13	public class FilterDemo {
14	static final int NCPU = Runtime.getRuntime().availableProcessors();
15
16	/**
17	* Sequential version, for performance comparison
18	*/
19	static<T> List<T> seqFilter(T[] list,
20	Ops.Predicate<T> pred) {
21	ArrayList<T> result = new ArrayList<T>();
22	int n = list.length;
23	for (int i = 0; i < n; ++i) {
24	T x = list[i];
25	if (pred.op(x))
26	result.add(x);
27	}
28	return result;
29	}
30
31	/**
32	* Slow/dumb prime check
33	*/
34	static final class IsPrime implements Ops.Predicate<Rand> {
35	public boolean op(Rand r) {
36	long n = r.seed;
37	if ((n & 1) == 0)
38	return false;
39	int bound = (int)(Math.sqrt(n));
40	for (int i = 3; i <= bound; i += 2)
41	if (n % i == 0)
42	return false;
43	return true;
44	}
45	}
46
47	/** for time conversion */
48	static final long NPS = (1000L * 1000 * 1000);
49
50	static final class NextRand implements Ops.Procedure<Rand> {
51	public void op(Rand r) {
52	r.next();
53	}
54	}
55
56	public static void main(String[] args) throws Exception {
57	int n = 1 << 9;
58	Rand[] array = new Rand[n];
59	for (int i = 0; i < n; ++i)
60	array[i] = new Rand(i);
61	final IsPrime pred = new IsPrime();
62	final NextRand nextRand = new NextRand();
63	long last, now;
64	double elapsed;
65	last = System.nanoTime();
66	List<Rand> seqResult = null;
67	int resultLength = -1;
68	boolean checked = false;
69	for (int k = 0; k < 2; ++k) {
70	List<Rand> result = seqFilter(array, pred);
71	now = System.nanoTime();
72	if (resultLength < 0) {
73	resultLength = result.size();
74	seqResult = result;
75	}
76	else if (resultLength != result.size())
77	throw new Error("wrong result size");
78	elapsed = (double)(now - last) / NPS;
79	last = now;
80	System.out.printf("seq: %7.3f\n", elapsed);
81	// for (Rand r : array) r.next();
82	}
83	int pass = 0;
84	int ps = 2;
85	ForkJoinPool fjp = new ForkJoinPool(ps);
86	ParallelArray<Rand> pa = ParallelArray.createUsingHandoff(array, fjp);
87	for (;;) {
88	last = System.nanoTime();
89	for (int k = 0; k < 4; ++k) {
90	List<Rand> result = pa.withFilter(pred).all().asList();
91	now = System.nanoTime();
92	if (!checked) {
93	checked = true;
94	if (!result.equals(seqResult))
95	throw new Error("res" + result + " seq" + seqResult);
96	}
97	elapsed = (double)(now - last) / NPS;
98	last = now;
99	System.out.printf("ps %2d: %7.3f\n", ps, elapsed);
100	}
101	if (pass == 0) {
102	if (ps >= NCPU)
103	pass = 1;
104	else
105	ps <<= 1;
106	}
107	else {
108	if (ps == 1)
109	break;
110	else
111	ps >>>= 1;
112	}
113	// pa.apply(nextRand);
114	fjp.setParallelism(ps);
115	}
116	fjp.shutdownNow();
117	fjp.awaitTermination(1, TimeUnit.SECONDS);
118	}
119
120	/**
121	* Unsynchronized version of java.util.Random algorithm.
122	*/
123	static final class Rand {
124	private static final long multiplier = 0x5DEECE66DL;
125	private static final long addend = 0xBL;
126	private static final long mask = (1L << 48) - 1;
127	private long seed;
128
129	Rand(long s) {
130	seed = s;
131	next();
132	next();
133	}
134	public int next() {
135	long nextseed = (seed * multiplier + addend) & mask;
136	seed = nextseed;
137	return ((int)(nextseed >>> 17)) & 0x7FFFFFFF;
138	}
139
140	public String toString() {
141	return String.valueOf(seed);
142	}
143	}
144
145	}