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;
    }


    /**
     * 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 final static long multiplier = 0x5DEECE66DL;
        private final static long addend = 0xBL;
        private final static 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:	1.5
Committed:	Thu Sep 15 16:55:40 2005 UTC (18 years, 8 months ago) by dl
Branch:	MAIN
Changes since 1.4:	+7 -6 lines
Log Message:	Misc minor test improvements
#	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			* generates 32 bit pseudo-random numbers.
21			* Adapted from http://www.snippets.org
22			*/
23			public static int compute1(int x) {
24			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			public static int compute2(int x) {
44			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			public static int compute3(int x) {
55			int t = (x % 127773) * 16807 - (x / 127773) * 2836;
56			return (t > 0)? t : t + 0x7fffffff;
57			}
58
59			/**
60			* Yet another random number generator
61			*/
62			public static int compute4(int x) {
63			return x * 134775813 + 1;
64			}
65
66
67			/**
68			* Yet another random number generator
69			*/
70			public static int compute5(int x) {
71			return 36969 * (x & 65535) + (x >> 16);
72			}
73
74	dl	1.3	/**
75			* Marsaglia xorshift (1, 3, 10)
76			*/
77	dl	1.4	public static int compute6(int seed) {
78			seed ^= seed << 1;
79			seed ^= seed >>> 3;
80			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			y ^= y << 6;
89			y ^= y >>> 21;
90			y ^= (y << 7);
91			return y;
92			}
93
94
95			/**
96			* Marsaglia xorshift for longs
97			*/
98			public static long compute8(long x) {
99			x ^= x << 13;
100			x ^= x >>> 7;
101			x ^= (x << 17);
102			return x;
103			}
104
105	dl	1.4	public static final class XorShift32Random {
106			static final AtomicInteger seq = new AtomicInteger(8862213);
107			int x = -1831433054;
108			public XorShift32Random(int seed) { x = seed; }
109			public XorShift32Random() {
110			this((int)System.nanoTime() + seq.getAndAdd(129));
111			}
112			public int next() {
113			x ^= x << 6;
114			x ^= x >>> 21;
115			x ^= (x << 7);
116			return x;
117			}
118			}
119
120	dl	1.3
121			/** Multiplication-free RNG from Marsaglia "Xorshift RNGs" paper */
122	dl	1.4	public static final class MarsagliaRandom {
123			static final AtomicInteger seq = new AtomicInteger(3122688);
124	dl	1.3	int x;
125			int y = 842502087;
126	dl	1.4	int z = -715159705;
127	dl	1.3	int w = 273326509;
128	dl	1.4	public MarsagliaRandom(int seed) { x = seed; }
129			public MarsagliaRandom() {
130			this((int)System.nanoTime() + seq.getAndAdd(129));
131			}
132	dl	1.3	public int next() {
133			int t = x ^ (x << 11);
134			x = y;
135			y = z;
136			z = w;
137	dl	1.4	return w = (w ^ (w >>> 19) ^ (t ^ (t >>> 8)));
138	dl	1.3	}
139			}
140	dl	1.1
141			/**
142	dl	1.4	* Unsynchronized version of java.util.Random algorithm.
143	dl	1.1	*/
144	dl	1.4	public static final class SimpleRandom {
145	dl	1.1	private final static long multiplier = 0x5DEECE66DL;
146			private final static long addend = 0xBL;
147			private final static long mask = (1L << 48) - 1;
148	dl	1.4	static final AtomicLong seq = new AtomicLong( -715159705);
149			private long seed;
150
151			SimpleRandom(long s) {
152			seed = s;
153			}
154
155			SimpleRandom() {
156			seed = System.nanoTime() + seq.getAndAdd(129);
157			}
158	dl	1.1
159			public void setSeed(long s) {
160			seed = s;
161			}
162
163			public int next() {
164			long nextseed = (seed * multiplier + addend) & mask;
165			seed = nextseed;
166			return ((int)(nextseed >>> 17)) & 0x7FFFFFFF;
167			}
168			}
169
170			public static class BarrierTimer implements Runnable {
171	dl	1.5	volatile boolean started;
172			volatile long startTime;
173			volatile long endTime;
174	dl	1.1	public void run() {
175			long t = System.nanoTime();
176	dl	1.5	if (!started) {
177			started = true;
178	dl	1.1	startTime = t;
179	dl	1.5	} else
180	dl	1.1	endTime = t;
181			}
182			public void clear() {
183	dl	1.5	started = false;
184	dl	1.1	}
185			public long getTime() {
186			return endTime - startTime;
187			}
188			}
189
190			public static String rightJustify(long n) {
191			// There's probably a better way to do this...
192			String field = " ";
193			String num = Long.toString(n);
194			if (num.length() >= field.length())
195			return num;
196			StringBuffer b = new StringBuffer(field);
197			b.replace(b.length()-num.length(), b.length(), num);
198			return b.toString();
199			}
200
201			}