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root/jsr166/jsr166/src/test/extra166y/DoubleCumulateDemo.java
Revision: 1.1
Committed: Sun Nov 1 22:00:35 2009 UTC (14 years, 6 months ago) by dl
Branch: MAIN
Log Message:
Move tests for extra166y

File Contents

# 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    
8     import jsr166y.*;
9     import extra166y.*;
10     import static extra166y.Ops.*;
11     import java.util.*;
12     import java.util.concurrent.*;
13    
14     public class DoubleCumulateDemo {
15     static final int NCPU = Runtime.getRuntime().availableProcessors();
16     /** for time conversion */
17     static final long NPS = (1000L * 1000 * 1000);
18    
19     static boolean check = false; // true;
20    
21     public static void main(String[] args) throws Exception {
22     check = args.length > 0;
23     int n = 1 << 19;
24     int reps = 1 << 9;
25     int tests = 4;
26     double[] array = new double[n];
27     long last, now;
28     double elapsed;
29    
30     for (int j = 0; j < tests; ++j) {
31     fill(array);
32     last = System.nanoTime();
33     for (int k = 0; k < reps; ++k) {
34     seqCumulate(array);
35     if (k == 0 && check)
36     check(array);
37     }
38     now = System.nanoTime();
39     elapsed = (double)(now - last) / (NPS);
40     System.out.printf("seq : %9.5f\n", elapsed);
41     }
42    
43     ForkJoinPool fjp = new ForkJoinPool(2);
44     for (int i = 2; i <= NCPU; i <<= 1) {
45     fjp.setParallelism(i);
46     oneRun(fjp, array, i, reps, tests);
47     }
48     for (int i = NCPU; i >= 1; i >>>= 1) {
49     fjp.setParallelism(i);
50     oneRun(fjp, array, i, reps, tests);
51     }
52     fjp.shutdown();
53     }
54    
55     static void oneRun(ForkJoinPool fjp,
56     double[] array, int nthreads,
57     int reps, int tests) throws Exception {
58     ParallelDoubleArray pa = ParallelDoubleArray.createUsingHandoff(array, fjp);
59     long last, now;
60     long steals = fjp.getStealCount();
61     // long syncs = fjp.getSyncCount();
62     for (int j = 0; j < tests; ++j) {
63     fill(array);
64     last = System.nanoTime();
65     for (int k = 0; k < reps; ++k) {
66     pa.cumulateSum();
67     if (k == 0 && check)
68     check(array);
69     }
70     now = System.nanoTime();
71     double elapsed = (double)(now - last) / (NPS);
72     last = now;
73     long sc = fjp.getStealCount();
74     long scount = (sc - steals) / reps;
75     steals = sc;
76     // long tc = fjp.getSyncCount();
77     // long tcount = (tc - syncs) / reps;
78     // syncs = tc;
79    
80     // System.out.printf("ps %2d: %9.5f Steals:%6d Syncs %6d\n", nthreads, elapsed, scount, tcount);
81     System.out.printf("ps %2d: %9.5f Steals:%6d\n", nthreads, elapsed, scount);
82     }
83     Thread.sleep(100);
84     }
85    
86     static void check(double[] array) {
87     for (int i = 0; i < array.length; ++i) {
88     double sum = i + 1;
89     if (array[i] != sum) {
90     System.out.println("i: " + i + " sum: " + sum + " element:" + array[i]);
91     throw new Error();
92     }
93     }
94     // System.out.print("*");
95     }
96    
97     static void fill(double[] array) {
98     for (int i = 0; i < array.length; ++i)
99     array[i] = 1;
100     }
101    
102     static double seqCumulate(double[] array) {
103     double sum = 0;
104     for (int i = 0; i < array.length; ++i)
105     sum = array[i] += sum;
106     return sum;
107     }
108     }