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 y) { 
        y ^= y << 1; 
        y ^= y >>> 3; 
        y ^= (y << 10);
        return y;
    }

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

    public static final long compute8InitialValue = 88172645463325252L;

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


    /** Multiplication-free RNG from Marsaglia "Xorshift RNGs" paper */
    public static class MarsagliaRandom {
        int x;
        int y = 842502087;
        int z = (int)(3579807591L & 0xffff);
        int w = 273326509;
        public MarsagliaRandom(int seed) { x = seed;  }
        public MarsagliaRandom() { this((int)System.nanoTime()); }
        public int next() {
            int t = x ^ (x << 11);
            x = y; 
            y = z; 
            z = w;
            return w = (w ^ (w >>> 19)) ^ (t ^ (t >>> 8));
        }
    }

    /**
     * An actually useful random number generator, but unsynchronized.
     * Basically same as java.util.Random.
     */
    public static 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(1);
        private long seed = System.nanoTime() + seq.getAndIncrement();

        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 {
        public volatile long startTime;
        public volatile long endTime;
        public void run() {
            long t = System.nanoTime();
            if (startTime == 0)
                startTime = t;
            else
                endTime = t;
        }
        public void clear() {
            startTime = 0;
            endTime = 0;
        }
        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:	1.3
Committed:	Fri Jun 10 15:45:19 2005 UTC (18 years, 11 months ago) by dl
Branch:	MAIN
Changes since 1.2:	+49 -0 lines
Log Message:	Add CAS timing test; use cheaper RNGs in others
#	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	* 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	/**
75	* Marsaglia xorshift (1, 3, 10)
76	*/
77	public static int compute6(int y) {
78	y ^= y << 1;
79	y ^= y >>> 3;
80	y ^= (y << 10);
81	return y;
82	}
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	public static final long compute8InitialValue = 88172645463325252L;
95
96	/**
97	* Marsaglia xorshift for longs
98	*/
99	public static long compute8(long x) {
100	x ^= x << 13;
101	x ^= x >>> 7;
102	x ^= (x << 17);
103	return x;
104	}
105
106
107	/** Multiplication-free RNG from Marsaglia "Xorshift RNGs" paper */
108	public static class MarsagliaRandom {
109	int x;
110	int y = 842502087;
111	int z = (int)(3579807591L & 0xffff);
112	int w = 273326509;
113	public MarsagliaRandom(int seed) { x = seed; }
114	public MarsagliaRandom() { this((int)System.nanoTime()); }
115	public int next() {
116	int t = x ^ (x << 11);
117	x = y;
118	y = z;
119	z = w;
120	return w = (w ^ (w >>> 19)) ^ (t ^ (t >>> 8));
121	}
122	}
123
124	/**
125	* An actually useful random number generator, but unsynchronized.
126	* Basically same as java.util.Random.
127	*/
128	public static class SimpleRandom {
129	private final static long multiplier = 0x5DEECE66DL;
130	private final static long addend = 0xBL;
131	private final static long mask = (1L << 48) - 1;
132	static final AtomicLong seq = new AtomicLong(1);
133	private long seed = System.nanoTime() + seq.getAndIncrement();
134
135	public void setSeed(long s) {
136	seed = s;
137	}
138
139	public int next() {
140	long nextseed = (seed * multiplier + addend) & mask;
141	seed = nextseed;
142	return ((int)(nextseed >>> 17)) & 0x7FFFFFFF;
143	}
144	}
145
146	public static class BarrierTimer implements Runnable {
147	public volatile long startTime;
148	public volatile long endTime;
149	public void run() {
150	long t = System.nanoTime();
151	if (startTime == 0)
152	startTime = t;
153	else
154	endTime = t;
155	}
156	public void clear() {
157	startTime = 0;
158	endTime = 0;
159	}
160	public long getTime() {
161	return endTime - startTime;
162	}
163	}
164
165	public static String rightJustify(long n) {
166	// There's probably a better way to do this...
167	String field = " ";
168	String num = Long.toString(n);
169	if (num.length() >= field.length())
170	return num;
171	StringBuffer b = new StringBuffer(field);
172	b.replace(b.length()-num.length(), b.length(), num);
173	return b.toString();
174	}
175
176	}