LoopHelpers.java revision 3984
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw/*
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw *
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * This code is free software; you can redistribute it and/or modify it
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * under the terms of the GNU General Public License version 2 only, as
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * published by the Free Software Foundation.
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw *
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * This code is distributed in the hope that it will be useful, but WITHOUT
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * version 2 for more details (a copy is included in the LICENSE file that
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * accompanied this code).
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw *
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * You should have received a copy of the GNU General Public License version
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * 2 along with this work; if not, write to the Free Software Foundation,
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw *
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * or visit www.oracle.com if you need additional information or have any
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * questions.
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw */
148c5f43199ca0b43fc8e3b643aab11cd66ea327Alan Wright
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross/*
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * This file is available under and governed by the GNU General Public
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * License version 2 only, as published by the Free Software Foundation.
bbf6f00c25b6a2bed23c35eac6d62998ecdb338cJordan Brown * However, the following notice accompanied the original version of this
cb174861876aea6950a7ab4ce944aff84b1914cdjoyce mcintosh * file:
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw *
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross * Written by Doug Lea with assistance from members of JCP JSR-166
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross * Expert Group and released to the public domain, as explained at
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross * http://creativecommons.org/publicdomain/zero/1.0/
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross */
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross/**
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross * Misc utilities in JSR166 performance tests
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross */
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Rossimport java.util.concurrent.*;
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Rossimport java.util.concurrent.atomic.*;
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Rossclass LoopHelpers {
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross // Some mindless computation to do between synchronizations...
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross /**
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross * generates 32 bit pseudo-random numbers.
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross * Adapted from http://www.snippets.org
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross */
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross public static int compute1(int x) {
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross int lo = 16807 * (x & 0xFFFF);
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross int hi = 16807 * (x >>> 16);
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross lo += (hi & 0x7FFF) << 16;
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross if ((lo & 0x80000000) != 0) {
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross lo &= 0x7fffffff;
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross ++lo;
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw }
c8ec8eea9849cac239663c46be8a7f5d2ba7ca00jose borrego lo += hi >>> 15;
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw if (lo == 0 || (lo & 0x80000000) != 0) {
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw lo &= 0x7fffffff;
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw ++lo;
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw }
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw return lo;
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw }
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw /**
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * Computes a linear congruential random number a random number
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * of times.
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw */
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw public static int compute2(int x) {
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw int loops = (x >>> 4) & 7;
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw while (loops-- > 0) {
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw x = (x * 2147483647) % 16807;
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw }
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw return x;
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw }
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw /**
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * An actually useful random number generator, but unsynchronized.
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw * Basically same as java.util.Random.
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw */
7b59d02d2a384be9a08087b14defadd214b3c1ddjb public static class SimpleRandom {
7b59d02d2a384be9a08087b14defadd214b3c1ddjb private static final long multiplier = 0x5DEECE66DL;
7b59d02d2a384be9a08087b14defadd214b3c1ddjb private static final long addend = 0xBL;
7b59d02d2a384be9a08087b14defadd214b3c1ddjb private static final long mask = (1L << 48) - 1;
7b59d02d2a384be9a08087b14defadd214b3c1ddjb static final AtomicLong seq = new AtomicLong(1);
7b59d02d2a384be9a08087b14defadd214b3c1ddjb private long seed = System.nanoTime() + seq.getAndIncrement();
7b59d02d2a384be9a08087b14defadd214b3c1ddjb
7b59d02d2a384be9a08087b14defadd214b3c1ddjb public void setSeed(long s) {
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb seed = s;
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw }
148c5f43199ca0b43fc8e3b643aab11cd66ea327Alan Wright
148c5f43199ca0b43fc8e3b643aab11cd66ea327Alan Wright public int next() {
7b59d02d2a384be9a08087b14defadd214b3c1ddjb long nextseed = (seed * multiplier + addend) & mask;
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw seed = nextseed;
7b59d02d2a384be9a08087b14defadd214b3c1ddjb return ((int)(nextseed >>> 17)) & 0x7FFFFFFF;
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw }
148c5f43199ca0b43fc8e3b643aab11cd66ea327Alan Wright }
148c5f43199ca0b43fc8e3b643aab11cd66ea327Alan Wright
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw public static class BarrierTimer implements Runnable {
148c5f43199ca0b43fc8e3b643aab11cd66ea327Alan Wright public volatile long startTime;
148c5f43199ca0b43fc8e3b643aab11cd66ea327Alan Wright public volatile long endTime;
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw public void run() {
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb long t = System.nanoTime();
148c5f43199ca0b43fc8e3b643aab11cd66ea327Alan Wright if (startTime == 0)
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb startTime = t;
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb else
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb endTime = t;
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb }
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb public void clear() {
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb startTime = 0;
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb endTime = 0;
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb }
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb public long getTime() {
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb return endTime - startTime;
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb }
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb }
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross public static String rightJustify(long n) {
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb // There's probably a better way to do this...
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb String field = " ";
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross String num = Long.toString(n);
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross if (num.length() >= field.length())
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross return num;
faa1795a28a5c712eed6d0a3f84d98c368a316c6jb StringBuffer b = new StringBuffer(field);
a90cf9f29973990687fa61de9f1f6ea22e924e40Gordon Ross b.replace(b.length()-num.length(), b.length(), num);
c8ec8eea9849cac239663c46be8a7f5d2ba7ca00jose borrego return b.toString();
7b59d02d2a384be9a08087b14defadd214b3c1ddjb }
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw}
da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0amw