test/loops/TimeUnitLoops.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/publicdomain/zero/1.0/
 */
import java.util.concurrent.*;

public class TimeUnitLoops {

    static final LoopHelpers.SimpleRandom rng = new LoopHelpers.SimpleRandom();

    /**
     * False value allows aggressive inlining of cvt() calls from
     * test(). True value prevents any inlining, requiring virtual
     * method dispatch.
     */
    static final boolean PREVENT_INLINING = true;

    // The following all are used by inlining prevention clause:
    static int index = 0;
    static final int NUNITS = 100;
    static final TimeUnit[] units = new TimeUnit[NUNITS];
    static {
        TimeUnit[] v = TimeUnit.values();
        for (int i = 0; i < NUNITS; ++i)
            units[i] = v[rng.next() % v.length];
    }

    public static void main(String[] args) throws Exception {
        long start = System.currentTimeMillis();
        long s = 0;
        for (int i = 0; i < 100; ++i) {
            s += test();
            if (s == start) System.out.println(" ");
        }
        long end = System.currentTimeMillis();
        System.out.println("Time: " + (end - start) + " ms");
    }

    static long test() {
        long sum = 0;
        int x = rng.next();
        for (int i = 0; i < 1000000; ++i) {
            long l = (long) x + (long) x;
            sum += cvt(l, TimeUnit.SECONDS);
            sum += TimeUnit.MILLISECONDS.toMicros(l+2);
            sum += cvt(l+17, TimeUnit.NANOSECONDS);
            sum += cvt(l+42, TimeUnit.MILLISECONDS);
            x = LoopHelpers.compute4(x);
        }
        return sum + x;
    }

    static long cvt(long d, TimeUnit u) {
        if (PREVENT_INLINING) {
            u = units[index];
            index = (index+1) % NUNITS;
        }

        return u.toNanos(d);
    }
}
Revision:	1.5
Committed:	Wed Dec 31 16:44:01 2014 UTC (9 years, 4 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.4:	+0 -1 lines
Log Message:	remove unused imports
#	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	jsr166	1.4	* http://creativecommons.org/publicdomain/zero/1.0/
5	dl	1.2	*/
6	dl	1.1	import java.util.concurrent.*;
7
8			public class TimeUnitLoops {
9
10			static final LoopHelpers.SimpleRandom rng = new LoopHelpers.SimpleRandom();
11
12			/**
13			* False value allows aggressive inlining of cvt() calls from
14			* test(). True value prevents any inlining, requiring virtual
15			* method dispatch.
16			*/
17			static final boolean PREVENT_INLINING = true;
18
19			// The following all are used by inlining prevention clause:
20			static int index = 0;
21			static final int NUNITS = 100;
22			static final TimeUnit[] units = new TimeUnit[NUNITS];
23			static {
24			TimeUnit[] v = TimeUnit.values();
25			for (int i = 0; i < NUNITS; ++i)
26			units[i] = v[rng.next() % v.length];
27			}
28
29			public static void main(String[] args) throws Exception {
30			long start = System.currentTimeMillis();
31			long s = 0;
32			for (int i = 0; i < 100; ++i) {
33			s += test();
34			if (s == start) System.out.println(" ");
35			}
36			long end = System.currentTimeMillis();
37			System.out.println("Time: " + (end - start) + " ms");
38			}
39
40			static long test() {
41			long sum = 0;
42			int x = rng.next();
43			for (int i = 0; i < 1000000; ++i) {
44	jsr166	1.3	long l = (long) x + (long) x;
45	dl	1.1	sum += cvt(l, TimeUnit.SECONDS);
46			sum += TimeUnit.MILLISECONDS.toMicros(l+2);
47			sum += cvt(l+17, TimeUnit.NANOSECONDS);
48			sum += cvt(l+42, TimeUnit.MILLISECONDS);
49			x = LoopHelpers.compute4(x);
50			}
51			return sum + x;
52			}
53
54			static long cvt(long d, TimeUnit u) {
55			if (PREVENT_INLINING) {
56			u = units[index];
57			index = (index+1) % NUNITS;
58			}
59
60			return u.toNanos(d);
61			}
62			}