/*
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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/*
* This file is available under and governed by the GNU General Public
* License version 2 only, as published by the Free Software Foundation.
* However, the following notice accompanied the original version of this
* file:
*
* 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/
*/
/*
* @test
* @bug 4486658
* @compile -source 1.5 MapLoops.java
* @run main/timeout=4700 MapLoops
* @summary Exercise multithreaded maps, by default ConcurrentHashMap.
* Multithreaded hash table test. Each thread does a random walk
* though elements of "key" array. On each iteration, it checks if
* table includes key. If absent, with probability pinsert it
* inserts it, and if present, with probability premove it removes
* it. (pinsert and premove are expressed as percentages to simplify
* parsing from command line.)
*/
import java.util.*;
import java.util.concurrent.*;
public class MapLoops {
static final int NKEYS = 100000;
static int pinsert = 60;
static int premove = 2;
static int maxThreads = 5;
static int nops = 1000000;
static int removesPerMaxRandom;
static int insertsPerMaxRandom;
static final ExecutorService pool = Executors.newCachedThreadPool();
public static void main(String[] args) throws Exception {
Class mapClass = null;
if (args.length > 0) {
try {
mapClass = Class.forName(args[0]);
} catch (ClassNotFoundException e) {
throw new RuntimeException("Class " + args[0] + " not found.");
}
}
else
mapClass = RWMap.class;
if (args.length > 1)
maxThreads = Integer.parseInt(args[1]);
if (args.length > 2)
nops = Integer.parseInt(args[2]);
if (args.length > 3)
pinsert = Integer.parseInt(args[3]);
if (args.length > 4)
premove = Integer.parseInt(args[4]);
// normalize probabilities wrt random number generator
removesPerMaxRandom = (int)(((double)premove/100.0 * 0x7FFFFFFFL));
insertsPerMaxRandom = (int)(((double)pinsert/100.0 * 0x7FFFFFFFL));
System.out.println("Using " + mapClass.getName());
Random rng = new Random(315312);
Integer[] key = new Integer[NKEYS];
for (int i = 0; i < key.length; ++i)
key[i] = new Integer(rng.nextInt());
// warmup
System.out.println("Warmup...");
for (int k = 0; k < 2; ++k) {
Map<Integer, Integer> map = (Map<Integer,Integer>)mapClass.newInstance();
LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
CyclicBarrier barrier = new CyclicBarrier(1, timer);
new Runner(map, key, barrier).run();
map.clear();
Thread.sleep(100);
}
for (int i = 1; i <= maxThreads; i += (i+1) >>> 1) {
System.out.print("Threads: " + i + "\t:");
Map<Integer, Integer> map = (Map<Integer,Integer>)mapClass.newInstance();
LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
CyclicBarrier barrier = new CyclicBarrier(i+1, timer);
for (int k = 0; k < i; ++k)
pool.execute(new Runner(map, key, barrier));
barrier.await();
barrier.await();
long time = timer.getTime();
long tpo = time / (i * (long)nops);
System.out.print(LoopHelpers.rightJustify(tpo) + " ns per op");
double secs = (double)(time) / 1000000000.0;
System.out.println("\t " + secs + "s run time");
map.clear();
}
pool.shutdown();
if (! pool.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS))
throw new Error();
}
static class Runner implements Runnable {
final Map<Integer,Integer> map;
final Integer[] key;
final LoopHelpers.SimpleRandom rng = new LoopHelpers.SimpleRandom();
final CyclicBarrier barrier;
int position;
int total;
Runner(Map<Integer,Integer> map, Integer[] key, CyclicBarrier barrier) {
this.map = map;
this.key = key;
this.barrier = barrier;
position = key.length / 2;
}
int step() {
// random-walk around key positions, bunching accesses
int r = rng.next();
position += (r & 7) - 3;
while (position >= key.length) position -= key.length;
while (position < 0) position += key.length;
Integer k = key[position];
Integer x = map.get(k);
if (x != null) {
if (x.intValue() != k.intValue())
throw new Error("bad mapping: " + x + " to " + k);
if (r < removesPerMaxRandom) {
// get awy from this position
position = r % key.length;
map.remove(k);
return 2;
}
else
total += LoopHelpers.compute2(LoopHelpers.compute1(x.intValue()));
}
else {
if (r < insertsPerMaxRandom) {
map.put(k, k);
return 2;
}
}
return 1;
}
public void run() {
try {
barrier.await();
int ops = nops;
while (ops > 0)
ops -= step();
barrier.await();
}
catch (Exception ex) {
ex.printStackTrace();
}
}
}
}