| 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 |
import java.util.Random; |
| 8 |
import java.util.Queue; |
| 9 |
|
| 10 |
public class UnboundedQueueFillEmptyLoops { |
| 11 |
static int maxSize = 50000; |
| 12 |
static Random rng = new Random(3153122688L); |
| 13 |
static volatile int total; |
| 14 |
static Integer[] numbers; |
| 15 |
|
| 16 |
public static void main(String[] args) throws Exception { |
| 17 |
if (args.length < 1) { |
| 18 |
System.out.printf( |
| 19 |
"Usage: UnboundedQueueFillEmptyLoops className [maxSize]%n"); |
| 20 |
System.exit(1); |
| 21 |
} |
| 22 |
|
| 23 |
final Class<?> klass; |
| 24 |
try { |
| 25 |
klass = Class.forName(args[0]); |
| 26 |
} catch (ClassNotFoundException e) { |
| 27 |
throw new RuntimeException("Class " + args[0] + " not found."); |
| 28 |
} |
| 29 |
|
| 30 |
if (args.length > 1) |
| 31 |
maxSize = Integer.parseInt(args[1]); |
| 32 |
|
| 33 |
System.out.printf("Class: %s size: %d%n", klass.getName(), maxSize); |
| 34 |
|
| 35 |
numbers = new Integer[maxSize]; |
| 36 |
for (int i = 0; i < maxSize; ++i) |
| 37 |
numbers[i] = rng.nextInt(128); |
| 38 |
|
| 39 |
oneRun(klass, maxSize); |
| 40 |
Thread.sleep(100); |
| 41 |
oneRun(klass, maxSize); |
| 42 |
Thread.sleep(100); |
| 43 |
oneRun(klass, maxSize); |
| 44 |
|
| 45 |
if (total == 0) System.out.print(" "); |
| 46 |
} |
| 47 |
|
| 48 |
static void oneRun(Class<?> klass, int n) throws Exception { |
| 49 |
Queue<Integer> q = |
| 50 |
(Queue<Integer>) klass.getConstructor().newInstance(); |
| 51 |
int sum = total; |
| 52 |
int m = rng.nextInt(numbers.length); |
| 53 |
long startTime = System.nanoTime(); |
| 54 |
for (int k = 0; k < n; ++k) { |
| 55 |
for (int i = 0; i < k; ++i) { |
| 56 |
if (m >= numbers.length) |
| 57 |
m = 0; |
| 58 |
q.offer(numbers[m++]); |
| 59 |
} |
| 60 |
for (Integer p; (p = q.poll()) != null; ) |
| 61 |
sum += p.intValue(); |
| 62 |
} |
| 63 |
total += sum; |
| 64 |
long endTime = System.nanoTime(); |
| 65 |
long time = endTime - startTime; |
| 66 |
double secs = (double) time / 1000000000.0; |
| 67 |
System.out.println("Time: " + secs); |
| 68 |
} |
| 69 |
|
| 70 |
} |
