test/extra166y/LongMapReduceDemo.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 static extra166y.Ops.*;
import java.util.*;
import java.util.concurrent.*;

public class LongMapReduceDemo {
    static final int NCPU = Runtime.getRuntime().availableProcessors();
    static final Random rng = new Random();

    /**
     * Sequential version, for performance comparison
     */
    static long seqMapReduce(long[] array,
                            LongOp mapper,
                            LongReducer reducer,
                            long base) {
        long n = array.length;
        long x = base;
        for (int i = 0; i < n; ++i)
            x = reducer.op(x, mapper.op(array[i]));
        return x;
    }

    // sample functions
    static final class GetNext implements LongOp {
        public long op(long seed) {
            long x = seed;
            x ^= x << 13;
            x ^= x >>> 7;
            x ^= (x << 17);
            return x;
        }
    }

    static final class Accum implements LongReducer {
        public long op(long x, long y) {
            return x + y;
        }
    }

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

    public static void main(String[] args) throws Exception {
        int n = 1 << 18;
        int reps = 1 << 8;
        long[] array = new long[n];
        for (int i = 0; i < n; ++i)
            array[i] = i + 1L;
        ForkJoinPool fjp = new ForkJoinPool(1);
        ParallelLongArray pa = ParallelLongArray.createUsingHandoff(array, fjp);
        final GetNext getNext = new GetNext();
        final Accum accum = new Accum();
        final long zero = 0L;
        long last, now;
        double elapsed;
        for (int j = 0; j < 2; ++j) {
            long rseed = rng.nextLong();
            resetSeeds(array, rseed);
            long seqsum = 0;
            last = System.nanoTime();
            for (int k = 0; k < reps; ++k) {
                seqsum += seqMapReduce(array, getNext, accum, zero);
                long tmp = array[k];
                array[k] = array[n - k - 1];
                array[n - k - 1] = tmp;
            }
            now = System.nanoTime();
            elapsed = (double)(now - last) / NPS;
            last = now;
            System.out.printf("sequential:    %7.3f\n", elapsed);
            for (int i = 2; i <= NCPU; i <<= 1) {
                resetSeeds(array, rseed);
                long sum = 0;
                fjp.setParallelism(i);
                last = System.nanoTime();
                for (int k = 0; k < reps; ++k) {
                    sum += pa.withMapping(getNext).reduce(accum, zero);
                    long tmp = array[k];
                    array[k] = array[n - k - 1];
                    array[n - k - 1] = tmp;
                }
                now = System.nanoTime();
                elapsed = (double)(now - last) / NPS;
                last = now;
                System.out.printf("poolSize %3d:  %7.3f\n", fjp.getParallelism(), elapsed);
                if (sum != seqsum) throw new Error("checksum");
            }
            for (int i = NCPU; i >= 1; i >>>= 1) {
                resetSeeds(array, rseed);
                long sum = 0;
                fjp.setParallelism(i);
                last = System.nanoTime();
                for (int k = 0; k < reps; ++k) {
                    sum += pa.withMapping(getNext).reduce(accum, zero);
                    long tmp = array[k];
                    array[k] = array[n - k - 1];
                    array[n - k - 1] = tmp;
                }
                now = System.nanoTime();
                elapsed = (double)(now - last) / NPS;
                last = now;
                System.out.printf("poolSize %3d:  %7.3f\n", fjp.getParallelism(), elapsed);
                if (sum != seqsum) throw new Error("checksum");
            }
        }
        fjp.shutdownNow();
        fjp.awaitTermination(1, TimeUnit.SECONDS);
        Thread.sleep(100);
    }

    static void resetSeeds(long[] array, long s) {
        for (int i = 0; i < array.length; ++i)
            array[i] = s++;
    }

}
Revision:	1.2
Committed:	Mon Nov 16 04:16:43 2009 UTC (14 years, 6 months ago) by jsr166
Branch:	MAIN
Changes since 1.1:	+6 -6 lines
Log Message:	whitespace
#	User	Rev	Content
1	dl	1.1	/*
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 static extra166y.Ops.*;
10			import java.util.*;
11			import java.util.concurrent.*;
12
13			public class LongMapReduceDemo {
14			static final int NCPU = Runtime.getRuntime().availableProcessors();
15			static final Random rng = new Random();
16
17			/**
18			* Sequential version, for performance comparison
19			*/
20	jsr166	1.2	static long seqMapReduce(long[] array,
21	dl	1.1	LongOp mapper,
22			LongReducer reducer,
23			long base) {
24			long n = array.length;
25			long x = base;
26	jsr166	1.2	for (int i = 0; i < n; ++i)
27	dl	1.1	x = reducer.op(x, mapper.op(array[i]));
28			return x;
29			}
30
31			// sample functions
32			static final class GetNext implements LongOp {
33			public long op(long seed) {
34			long x = seed;
35	jsr166	1.2	x ^= x << 13;
36			x ^= x >>> 7;
37	dl	1.1	x ^= (x << 17);
38			return x;
39			}
40			}
41
42			static final class Accum implements LongReducer {
43			public long op(long x, long y) {
44			return x + y;
45			}
46			}
47
48			/** for time conversion */
49			static final long NPS = (1000L * 1000 * 1000);
50
51			public static void main(String[] args) throws Exception {
52			int n = 1 << 18;
53			int reps = 1 << 8;
54			long[] array = new long[n];
55	jsr166	1.2	for (int i = 0; i < n; ++i)
56	dl	1.1	array[i] = i + 1L;
57			ForkJoinPool fjp = new ForkJoinPool(1);
58			ParallelLongArray pa = ParallelLongArray.createUsingHandoff(array, fjp);
59			final GetNext getNext = new GetNext();
60			final Accum accum = new Accum();
61			final long zero = 0L;
62			long last, now;
63			double elapsed;
64			for (int j = 0; j < 2; ++j) {
65			long rseed = rng.nextLong();
66			resetSeeds(array, rseed);
67			long seqsum = 0;
68			last = System.nanoTime();
69			for (int k = 0; k < reps; ++k) {
70			seqsum += seqMapReduce(array, getNext, accum, zero);
71			long tmp = array[k];
72			array[k] = array[n - k - 1];
73			array[n - k - 1] = tmp;
74			}
75			now = System.nanoTime();
76			elapsed = (double)(now - last) / NPS;
77			last = now;
78			System.out.printf("sequential: %7.3f\n", elapsed);
79			for (int i = 2; i <= NCPU; i <<= 1) {
80			resetSeeds(array, rseed);
81			long sum = 0;
82			fjp.setParallelism(i);
83			last = System.nanoTime();
84			for (int k = 0; k < reps; ++k) {
85			sum += pa.withMapping(getNext).reduce(accum, zero);
86			long tmp = array[k];
87			array[k] = array[n - k - 1];
88			array[n - k - 1] = tmp;
89			}
90			now = System.nanoTime();
91			elapsed = (double)(now - last) / NPS;
92			last = now;
93			System.out.printf("poolSize %3d: %7.3f\n", fjp.getParallelism(), elapsed);
94			if (sum != seqsum) throw new Error("checksum");
95			}
96			for (int i = NCPU; i >= 1; i >>>= 1) {
97			resetSeeds(array, rseed);
98			long sum = 0;
99			fjp.setParallelism(i);
100			last = System.nanoTime();
101			for (int k = 0; k < reps; ++k) {
102			sum += pa.withMapping(getNext).reduce(accum, zero);
103			long tmp = array[k];
104			array[k] = array[n - k - 1];
105			array[n - k - 1] = tmp;
106			}
107			now = System.nanoTime();
108			elapsed = (double)(now - last) / NPS;
109			last = now;
110			System.out.printf("poolSize %3d: %7.3f\n", fjp.getParallelism(), elapsed);
111			if (sum != seqsum) throw new Error("checksum");
112			}
113			}
114			fjp.shutdownNow();
115			fjp.awaitTermination(1, TimeUnit.SECONDS);
116			Thread.sleep(100);
117			}
118
119			static void resetSeeds(long[] array, long s) {
120			for (int i = 0; i < array.length; ++i)
121			array[i] = s++;
122			}
123	jsr166	1.2
124	dl	1.1	}