test/loops/LoopHelpers.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
 */
/**
 * Misc utilities in JSR166 performance tests
 */

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

class LoopHelpers {

    static final SimpleRandom staticRNG = new SimpleRandom();

    // Some mindless computation to do between synchronizations...

    /**
     * generates 32 bit pseudo-random numbers.
     * Adapted from http://www.snippets.org
     */
    public static int compute1(int x) {
        int lo = 16807 * (x & 0xFFFF);
        int hi = 16807 * (x >>> 16);
        lo += (hi & 0x7FFF) << 16;
        if ((lo & 0x80000000) != 0) {
            lo &= 0x7fffffff;
            ++lo;
        }
        lo += hi >>> 15;
        if (lo == 0 || (lo & 0x80000000) != 0) {
            lo &= 0x7fffffff;
            ++lo;
        }
        return lo;
    }

    /**
     *  Computes a linear congruential random number a random number
     *  of times.
     */
    public static int compute2(int x) {
        int loops = (x >>> 4) & 7;
        while (loops-- > 0) {
            x = (x * 2147483647) % 16807;
        }
        return x;
    }

    /**
     * Yet another random number generator
     */
    public static int compute3(int x) {
        int t = (x % 127773) * 16807 - (x / 127773) * 2836;
        return (t > 0) ? t : t + 0x7fffffff;
    }

    /**
     * Yet another random number generator
     */
    public static int compute4(int x) {
        return x * 134775813 + 1;
    }


    /**
     * Yet another random number generator
     */
    public static int compute5(int x) {
        return 36969 * (x & 65535) + (x >> 16);
    }

    /**
     * Marsaglia xorshift (1, 3, 10)
     */
    public static int compute6(int seed) {
        seed ^= seed << 1;
        seed ^= seed >>> 3;
        seed ^= (seed << 10);
        return seed;
    }

    /**
     * Marsaglia xorshift (6, 21, 7)
     */
    public static int compute7(int y) {
        y ^= y << 6;
        y ^= y >>> 21;
        y ^= (y << 7);
        return y;
    }

    // FNV: (x ^ 0x811c9dc5) * 0x01000193;  15485863;

    /**
     * Marsaglia xorshift for longs
     */
    public static long compute8(long x) {
        x ^= x << 13;
        x ^= x >>> 7;
        x ^= (x << 17);
        return x;
    }

    public static final class XorShift32Random {
        static final AtomicInteger seq = new AtomicInteger(8862213);
        int x = -1831433054;
        public XorShift32Random(int seed) { x = seed;  }
        public XorShift32Random() {
            this((int) System.nanoTime() + seq.getAndAdd(129));
        }
        public int next() {
            x ^= x << 6;
            x ^= x >>> 21;
            x ^= (x << 7);
            return x;
        }
    }


    /** Multiplication-free RNG from Marsaglia "Xorshift RNGs" paper */
    public static final class MarsagliaRandom {
        static final AtomicInteger seq = new AtomicInteger(3122688);
        int x;
        int y = 842502087;
        int z = -715159705;
        int w = 273326509;
        public MarsagliaRandom(int seed) { x = seed; }
        public MarsagliaRandom() {
            this((int) System.nanoTime() + seq.getAndAdd(129));
        }
        public int next() {
            int t = x ^ (x << 11);
            x = y;
            y = z;
            z = w;
            return w = (w ^ (w >>> 19) ^ (t ^ (t >>> 8)));
        }
    }

    /**
     * Unsynchronized version of java.util.Random algorithm.
     */
    public static final class SimpleRandom {
        private static final long multiplier = 0x5DEECE66DL;
        private static final long addend = 0xBL;
        private static final long mask = (1L << 48) - 1;
        static final AtomicLong seq = new AtomicLong( -715159705);
        private long seed;

        SimpleRandom(long s) {
            seed = s;
        }

        SimpleRandom() {
            seed = System.nanoTime() + seq.getAndAdd(129);
        }

        public void setSeed(long s) {
            seed = s;
        }

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

    public static class BarrierTimer implements Runnable {
        volatile boolean started;
        volatile long startTime;
        volatile long endTime;
        public void run() {
            long t = System.nanoTime();
            if (!started) {
                started = true;
                startTime = t;
            } else
                endTime = t;
        }
        public void clear() {
            started = false;
        }
        public long getTime() {
            return endTime - startTime;
        }
    }

    public static String rightJustify(long n) {
        // There's probably a better way to do this...
        String field = "         ";
        String num = Long.toString(n);
        if (num.length() >= field.length())
            return num;
        StringBuffer b = new StringBuffer(field);
        b.replace(b.length()-num.length(), b.length(), num);
        return b.toString();
    }

}
Revision:	1.10
Committed:	Mon Sep 27 19:15:15 2010 UTC (13 years, 7 months ago) by jsr166
Branch:	MAIN
Changes since 1.9:	+3 -3 lines
Log Message:	use blessed declaration modifier order
#	User	Rev	Content
1	dl	1.2	/*
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	dl	1.1	/**
7			* Misc utilities in JSR166 performance tests
8			*/
9
10			import java.util.concurrent.*;
11			import java.util.concurrent.atomic.*;
12
13			class LoopHelpers {
14
15			static final SimpleRandom staticRNG = new SimpleRandom();
16
17			// Some mindless computation to do between synchronizations...
18
19			/**
20	jsr166	1.7	* generates 32 bit pseudo-random numbers.
21	dl	1.1	* Adapted from http://www.snippets.org
22			*/
23	jsr166	1.7	public static int compute1(int x) {
24	dl	1.1	int lo = 16807 * (x & 0xFFFF);
25			int hi = 16807 * (x >>> 16);
26			lo += (hi & 0x7FFF) << 16;
27			if ((lo & 0x80000000) != 0) {
28			lo &= 0x7fffffff;
29			++lo;
30			}
31			lo += hi >>> 15;
32			if (lo == 0 \|\| (lo & 0x80000000) != 0) {
33			lo &= 0x7fffffff;
34			++lo;
35			}
36			return lo;
37			}
38
39			/**
40			* Computes a linear congruential random number a random number
41			* of times.
42			*/
43	jsr166	1.7	public static int compute2(int x) {
44	dl	1.1	int loops = (x >>> 4) & 7;
45			while (loops-- > 0) {
46			x = (x * 2147483647) % 16807;
47			}
48			return x;
49			}
50
51			/**
52			* Yet another random number generator
53			*/
54	jsr166	1.7	public static int compute3(int x) {
55	dl	1.1	int t = (x % 127773) * 16807 - (x / 127773) * 2836;
56	jsr166	1.8	return (t > 0) ? t : t + 0x7fffffff;
57	dl	1.1	}
58
59			/**
60			* Yet another random number generator
61			*/
62	jsr166	1.7	public static int compute4(int x) {
63	dl	1.1	return x * 134775813 + 1;
64			}
65
66
67			/**
68			* Yet another random number generator
69			*/
70	jsr166	1.7	public static int compute5(int x) {
71	dl	1.1	return 36969 * (x & 65535) + (x >> 16);
72			}
73
74	dl	1.3	/**
75			* Marsaglia xorshift (1, 3, 10)
76			*/
77	jsr166	1.7	public static int compute6(int seed) {
78			seed ^= seed << 1;
79			seed ^= seed >>> 3;
80	dl	1.4	seed ^= (seed << 10);
81			return seed;
82	dl	1.3	}
83
84			/**
85			* Marsaglia xorshift (6, 21, 7)
86			*/
87			public static int compute7(int y) {
88	jsr166	1.7	y ^= y << 6;
89			y ^= y >>> 21;
90	dl	1.3	y ^= (y << 7);
91			return y;
92			}
93
94	dl	1.6	// FNV: (x ^ 0x811c9dc5) * 0x01000193; 15485863;
95	dl	1.3
96			/**
97			* Marsaglia xorshift for longs
98			*/
99	jsr166	1.7	public static long compute8(long x) {
100			x ^= x << 13;
101			x ^= x >>> 7;
102	dl	1.3	x ^= (x << 17);
103			return x;
104			}
105
106	dl	1.4	public static final class XorShift32Random {
107			static final AtomicInteger seq = new AtomicInteger(8862213);
108			int x = -1831433054;
109			public XorShift32Random(int seed) { x = seed; }
110	jsr166	1.7	public XorShift32Random() {
111	jsr166	1.9	this((int) System.nanoTime() + seq.getAndAdd(129));
112	dl	1.4	}
113			public int next() {
114	jsr166	1.7	x ^= x << 6;
115			x ^= x >>> 21;
116	dl	1.4	x ^= (x << 7);
117			return x;
118			}
119			}
120
121	dl	1.3
122			/** Multiplication-free RNG from Marsaglia "Xorshift RNGs" paper */
123	dl	1.4	public static final class MarsagliaRandom {
124			static final AtomicInteger seq = new AtomicInteger(3122688);
125	dl	1.3	int x;
126			int y = 842502087;
127	dl	1.4	int z = -715159705;
128	dl	1.3	int w = 273326509;
129	dl	1.4	public MarsagliaRandom(int seed) { x = seed; }
130	jsr166	1.7	public MarsagliaRandom() {
131	jsr166	1.9	this((int) System.nanoTime() + seq.getAndAdd(129));
132	dl	1.4	}
133	dl	1.3	public int next() {
134			int t = x ^ (x << 11);
135	jsr166	1.7	x = y;
136			y = z;
137	dl	1.3	z = w;
138	dl	1.4	return w = (w ^ (w >>> 19) ^ (t ^ (t >>> 8)));
139	dl	1.3	}
140			}
141	dl	1.1
142			/**
143	dl	1.4	* Unsynchronized version of java.util.Random algorithm.
144	dl	1.1	*/
145	dl	1.4	public static final class SimpleRandom {
146	jsr166	1.10	private static final long multiplier = 0x5DEECE66DL;
147			private static final long addend = 0xBL;
148			private static final long mask = (1L << 48) - 1;
149	dl	1.4	static final AtomicLong seq = new AtomicLong( -715159705);
150			private long seed;
151
152			SimpleRandom(long s) {
153			seed = s;
154			}
155
156			SimpleRandom() {
157			seed = System.nanoTime() + seq.getAndAdd(129);
158			}
159	dl	1.1
160			public void setSeed(long s) {
161			seed = s;
162			}
163
164			public int next() {
165			long nextseed = (seed * multiplier + addend) & mask;
166			seed = nextseed;
167	jsr166	1.9	return ((int) (nextseed >>> 17)) & 0x7FFFFFFF;
168	dl	1.1	}
169			}
170
171			public static class BarrierTimer implements Runnable {
172	dl	1.5	volatile boolean started;
173			volatile long startTime;
174			volatile long endTime;
175	dl	1.1	public void run() {
176			long t = System.nanoTime();
177	dl	1.5	if (!started) {
178			started = true;
179	dl	1.1	startTime = t;
180	dl	1.5	} else
181	dl	1.1	endTime = t;
182			}
183			public void clear() {
184	dl	1.5	started = false;
185	dl	1.1	}
186			public long getTime() {
187			return endTime - startTime;
188			}
189			}
190
191			public static String rightJustify(long n) {
192			// There's probably a better way to do this...
193			String field = " ";
194			String num = Long.toString(n);
195			if (num.length() >= field.length())
196			return num;
197			StringBuffer b = new StringBuffer(field);
198			b.replace(b.length()-num.length(), b.length(), num);
199			return b.toString();
200			}
201	jsr166	1.7
202	dl	1.1	}