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/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
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* Expert Group and released to the public domain, as explained at |
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* http://creativecommons.org/publicdomain/zero/1.0/ |
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*/ |
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|
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import java.util.*; |
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import java.util.concurrent.*; |
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|
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public class MapLoops { |
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static int nkeys = 1000; |
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static int pinsert = 60; |
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static int premove = 2; |
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static int maxThreads = 100; |
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static int nops = 1000000; |
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static int removesPerMaxRandom; |
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static int insertsPerMaxRandom; |
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|
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static final ExecutorService pool = Executors.newCachedThreadPool(); |
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|
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public static void main(String[] args) throws Exception { |
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|
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Class mapClass = null; |
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if (args.length > 0) { |
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try { |
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mapClass = Class.forName(args[0]); |
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} catch (ClassNotFoundException e) { |
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throw new RuntimeException("Class " + args[0] + " not found."); |
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} |
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} |
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else |
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mapClass = java.util.concurrent.ConcurrentHashMap.class; |
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|
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if (args.length > 1) |
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maxThreads = Integer.parseInt(args[1]); |
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|
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if (args.length > 2) |
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nkeys = Integer.parseInt(args[2]); |
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|
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if (args.length > 3) |
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pinsert = Integer.parseInt(args[3]); |
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|
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if (args.length > 4) |
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premove = Integer.parseInt(args[4]); |
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|
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if (args.length > 5) |
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nops = Integer.parseInt(args[5]); |
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|
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// normalize probabilities wrt random number generator |
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removesPerMaxRandom = (int)(((double)premove/100.0 * 0x7FFFFFFFL)); |
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insertsPerMaxRandom = (int)(((double)pinsert/100.0 * 0x7FFFFFFFL)); |
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|
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System.out.print("Class: " + mapClass.getName()); |
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System.out.print(" threads: " + maxThreads); |
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System.out.print(" size: " + nkeys); |
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System.out.print(" ins: " + pinsert); |
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System.out.print(" rem: " + premove); |
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System.out.print(" ops: " + nops); |
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System.out.println(); |
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|
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int k = 1; |
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int warmups = 2; |
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for (int i = 1; i <= maxThreads;) { |
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Thread.sleep(100); |
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test(i, nkeys, mapClass); |
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if (warmups > 0) |
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--warmups; |
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else if (i == k) { |
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k = i << 1; |
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i = i + (i >>> 1); |
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} |
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else if (i == 1 && k == 2) { |
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i = k; |
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warmups = 1; |
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} |
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else |
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i = k; |
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} |
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pool.shutdown(); |
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} |
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|
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static Integer[] makeKeys(int n) { |
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LoopHelpers.SimpleRandom rng = new LoopHelpers.SimpleRandom(); |
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Integer[] key = new Integer[n]; |
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for (int i = 0; i < key.length; ++i) |
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key[i] = new Integer(rng.next()); |
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return key; |
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} |
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|
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static void shuffleKeys(Integer[] key) { |
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Random rng = new Random(); |
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for (int i = key.length; i > 1; --i) { |
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int j = rng.nextInt(i); |
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Integer tmp = key[j]; |
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key[j] = key[i-1]; |
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key[i-1] = tmp; |
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} |
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} |
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|
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static void test(int i, int nkeys, Class mapClass) throws Exception { |
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System.out.print("Threads: " + i + "\t:"); |
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Map<Integer, Integer> map = (Map<Integer,Integer>)mapClass.newInstance(); |
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Integer[] key = makeKeys(nkeys); |
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// Uncomment to start with a non-empty table |
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// for (int j = 0; j < nkeys; j += 4) // start 1/4 occupied |
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// map.put(key[j], key[j]); |
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shuffleKeys(key); |
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LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer(); |
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CyclicBarrier barrier = new CyclicBarrier(i+1, timer); |
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for (int t = 0; t < i; ++t) |
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pool.execute(new Runner(t, map, key, barrier)); |
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barrier.await(); |
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barrier.await(); |
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long time = timer.getTime(); |
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long tpo = time / (i * (long) nops); |
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System.out.print(LoopHelpers.rightJustify(tpo) + " ns per op"); |
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double secs = (double) time / 1000000000.0; |
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System.out.println("\t " + secs + "s run time"); |
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map.clear(); |
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} |
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|
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static class Runner implements Runnable { |
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final Map<Integer,Integer> map; |
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final Integer[] key; |
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final LoopHelpers.SimpleRandom rng; |
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final CyclicBarrier barrier; |
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int position; |
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int total; |
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|
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Runner(int id, Map<Integer,Integer> map, Integer[] key, CyclicBarrier barrier) { |
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this.map = map; |
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this.key = key; |
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this.barrier = barrier; |
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position = key.length / 2; |
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rng = new LoopHelpers.SimpleRandom((id + 1) * 8862213513L); |
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rng.next(); |
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} |
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|
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int step() { |
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// random-walk around key positions, bunching accesses |
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int r = rng.next(); |
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position += (r & 7) - 3; |
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while (position >= key.length) position -= key.length; |
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while (position < 0) position += key.length; |
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|
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Integer k = key[position]; |
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Integer x = map.get(k); |
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|
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if (x != null) { |
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if (x.intValue() != k.intValue()) |
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throw new Error("bad mapping: " + x + " to " + k); |
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|
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if (r < removesPerMaxRandom) { |
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if (map.remove(k) != null) { |
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position = total % key.length; // move from position |
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return 2; |
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} |
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} |
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} |
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else if (r < insertsPerMaxRandom) { |
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++position; |
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map.put(k, k); |
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return 2; |
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} |
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|
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// Uncomment to add a little computation between accesses |
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// total += LoopHelpers.compute1(k.intValue()); |
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total += r; |
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return 1; |
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} |
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|
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public void run() { |
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try { |
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barrier.await(); |
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int ops = nops; |
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while (ops > 0) |
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ops -= step(); |
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barrier.await(); |
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} |
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catch (Exception ex) { |
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ex.printStackTrace(); |
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} |
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} |
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} |
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} |
