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Comparing jsr166/src/test/loops/LoopHelpers.java (file contents):
Revision 1.3 by dl, Fri Jun 10 15:45:19 2005 UTC vs.
Revision 1.13 by jsr166, Sat Feb 16 20:50:29 2013 UTC

# Line 1 | Line 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 < * Misc utilities in JSR166 performance tests
4 > * http://creativecommons.org/publicdomain/zero/1.0/
5   */
6  
7   import java.util.concurrent.*;
8   import java.util.concurrent.atomic.*;
9  
10 + /**
11 + * Misc utilities in JSR166 performance tests
12 + */
13   class LoopHelpers {
14  
15      static final SimpleRandom staticRNG = new SimpleRandom();
# Line 17 | Line 17 | class LoopHelpers {
17      // Some mindless computation to do between synchronizations...
18  
19      /**
20 <     * generates 32 bit pseudo-random numbers.
20 >     * generates 32 bit pseudo-random numbers.
21       * Adapted from http://www.snippets.org
22       */
23 <    public static int compute1(int x) {
23 >    public static int compute1(int x) {
24          int lo = 16807 * (x & 0xFFFF);
25          int hi = 16807 * (x >>> 16);
26          lo += (hi & 0x7FFF) << 16;
# Line 40 | Line 40 | class LoopHelpers {
40       *  Computes a linear congruential random number a random number
41       *  of times.
42       */
43 <    public static int compute2(int x) {
43 >    public static int compute2(int x) {
44          int loops = (x >>> 4) & 7;
45          while (loops-- > 0) {
46              x = (x * 2147483647) % 16807;
# Line 51 | Line 51 | class LoopHelpers {
51      /**
52       * Yet another random number generator
53       */
54 <    public static int compute3(int x) {
54 >    public static int compute3(int x) {
55          int t = (x % 127773) * 16807 - (x / 127773) * 2836;
56 <        return (t > 0)? t : t + 0x7fffffff;
56 >        return (t > 0) ? t : t + 0x7fffffff;
57      }
58  
59      /**
60       * Yet another random number generator
61       */
62 <    public static int compute4(int x) {
62 >    public static int compute4(int x) {
63          return x * 134775813 + 1;
64      }
65  
# Line 67 | Line 67 | class LoopHelpers {
67      /**
68       * Yet another random number generator
69       */
70 <    public static int compute5(int x) {
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;
77 >    public static int compute6(int seed) {
78 >        seed ^= seed << 1;
79 >        seed ^= seed >>> 3;
80 >        seed ^= (seed << 10);
81 >        return seed;
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;
88 >        y ^= y << 6;
89 >        y ^= y >>> 21;
90          y ^= (y << 7);
91          return y;
92      }
93  
94 <    public static final long compute8InitialValue = 88172645463325252L;
94 >    // FNV: (x ^ 0x811c9dc5) * 0x01000193;  15485863;
95  
96      /**
97       * Marsaglia xorshift for longs
98       */
99 <    public static long compute8(long x) {
100 <        x ^= x << 13;
101 <        x ^= x >>> 7;
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 +    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 +        public XorShift32Random() {
111 +            this((int) System.nanoTime() + seq.getAndAdd(129));
112 +        }
113 +        public int next() {
114 +            x ^= x << 6;
115 +            x ^= x >>> 21;
116 +            x ^= (x << 7);
117 +            return x;
118 +        }
119 +    }
120 +
121  
122      /** Multiplication-free RNG from Marsaglia "Xorshift RNGs" paper */
123 <    public static class MarsagliaRandom {
123 >    public static final class MarsagliaRandom {
124 >        static final AtomicInteger seq = new AtomicInteger(3122688);
125          int x;
126          int y = 842502087;
127 <        int z = (int)(3579807591L & 0xffff);
127 >        int z = -715159705;
128          int w = 273326509;
129 <        public MarsagliaRandom(int seed) { x = seed;  }
130 <        public MarsagliaRandom() { this((int)System.nanoTime()); }
129 >        public MarsagliaRandom(int seed) { x = seed; }
130 >        public MarsagliaRandom() {
131 >            this((int) System.nanoTime() + seq.getAndAdd(129));
132 >        }
133          public int next() {
134              int t = x ^ (x << 11);
135 <            x = y;
136 <            y = z;
135 >            x = y;
136 >            y = z;
137              z = w;
138 <            return w = (w ^ (w >>> 19)) ^ (t ^ (t >>> 8));
138 >            return w = (w ^ (w >>> 19) ^ (t ^ (t >>> 8)));
139          }
140      }
141  
142      /**
143 <     * An actually useful random number generator, but unsynchronized.
126 <     * Basically same as java.util.Random.
143 >     * Unsynchronized version of java.util.Random algorithm.
144       */
145 <    public static class SimpleRandom {
146 <        private final static long multiplier = 0x5DEECE66DL;
147 <        private final static long addend = 0xBL;
148 <        private final static long mask = (1L << 48) - 1;
149 <        static final AtomicLong seq = new AtomicLong(1);
150 <        private long seed = System.nanoTime() + seq.getAndIncrement();
145 >    public static final class SimpleRandom {
146 >        private static final long multiplier = 0x5DEECE66DL;
147 >        private static final long addend = 0xBL;
148 >        private static final long mask = (1L << 48) - 1;
149 >        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  
160          public void setSeed(long s) {
161              seed = s;
# Line 139 | Line 164 | class LoopHelpers {
164          public int next() {
165              long nextseed = (seed * multiplier + addend) & mask;
166              seed = nextseed;
167 <            return ((int)(nextseed >>> 17)) & 0x7FFFFFFF;
167 >            return ((int) (nextseed >>> 17)) & 0x7FFFFFFF;
168          }
169      }
170  
171      public static class BarrierTimer implements Runnable {
172 <        public volatile long startTime;
173 <        public volatile long endTime;
172 >        volatile boolean started;
173 >        volatile long startTime;
174 >        volatile long endTime;
175          public void run() {
176              long t = System.nanoTime();
177 <            if (startTime == 0)
177 >            if (!started) {
178 >                started = true;
179                  startTime = t;
180 <            else
180 >            } else
181                  endTime = t;
182          }
183          public void clear() {
184 <            startTime = 0;
158 <            endTime = 0;
184 >            started = false;
185          }
186          public long getTime() {
187              return endTime - startTime;
# Line 172 | Line 198 | class LoopHelpers {
198          b.replace(b.length()-num.length(), b.length(), num);
199          return b.toString();
200      }
201 <  
201 >
202   }

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