concurrent/BlockingQueue/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/publicdomain/zero/1.0/
 */

/**
 * Misc utilities in JSR166 performance tests
 */
class LoopHelpers {

    // 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;
    }

    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;
        StringBuilder b = new StringBuilder(field);
        b.replace(b.length()-num.length(), b.length(), num);
        return b.toString();
    }

}
Revision:	1.10
Committed:	Sun Jan 7 22:18:01 2018 UTC (6 years, 4 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.9:	+1 -1 lines
Log Message:	s/StringBuffer/StringBuilder/
#	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/publicdomain/zero/1.0/
5	*/
6
7	/**
8	* Misc utilities in JSR166 performance tests
9	*/
10	class LoopHelpers {
11
12	// Some mindless computation to do between synchronizations...
13
14	/**
15	* generates 32 bit pseudo-random numbers.
16	* Adapted from http://www.snippets.org
17	*/
18	public static int compute1(int x) {
19	int lo = 16807 * (x & 0xFFFF);
20	int hi = 16807 * (x >>> 16);
21	lo += (hi & 0x7FFF) << 16;
22	if ((lo & 0x80000000) != 0) {
23	lo &= 0x7fffffff;
24	++lo;
25	}
26	lo += hi >>> 15;
27	if (lo == 0 \|\| (lo & 0x80000000) != 0) {
28	lo &= 0x7fffffff;
29	++lo;
30	}
31	return lo;
32	}
33
34	/**
35	* Computes a linear congruential random number a random number
36	* of times.
37	*/
38	public static int compute2(int x) {
39	int loops = (x >>> 4) & 7;
40	while (loops-- > 0) {
41	x = (x * 2147483647) % 16807;
42	}
43	return x;
44	}
45
46	public static class BarrierTimer implements Runnable {
47	public volatile long startTime;
48	public volatile long endTime;
49	public void run() {
50	long t = System.nanoTime();
51	if (startTime == 0)
52	startTime = t;
53	else
54	endTime = t;
55	}
56	public void clear() {
57	startTime = 0;
58	endTime = 0;
59	}
60	public long getTime() {
61	return endTime - startTime;
62	}
63	}
64
65	public static String rightJustify(long n) {
66	// There's probably a better way to do this...
67	String field = " ";
68	String num = Long.toString(n);
69	if (num.length() >= field.length())
70	return num;
71	StringBuilder b = new StringBuilder(field);
72	b.replace(b.length()-num.length(), b.length(), num);
73	return b.toString();
74	}
75
76	}