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/licenses/publicdomain |
5 |
*/ |
6 |
|
7 |
import java.util.*; |
8 |
import java.util.concurrent.*; |
9 |
import java.util.concurrent.locks.*; |
10 |
import java.util.concurrent.atomic.*; |
11 |
|
12 |
public class UnboundedQueueFillEmptyLoops { |
13 |
static int maxSize = 10000; |
14 |
static Random rng = new Random(3153122688L); |
15 |
static volatile int total; |
16 |
static Integer[] numbers; |
17 |
|
18 |
public static void main(String[] args) throws Exception { |
19 |
Class klass = null; |
20 |
if (args.length > 0) { |
21 |
try { |
22 |
klass = Class.forName(args[0]); |
23 |
} catch(ClassNotFoundException e) { |
24 |
throw new RuntimeException("Class " + args[0] + " not found."); |
25 |
} |
26 |
} |
27 |
|
28 |
if (args.length > 2) |
29 |
maxSize = Integer.parseInt(args[2]); |
30 |
|
31 |
System.out.print("Class: " + klass.getName()); |
32 |
System.out.println(" size: " + maxSize); |
33 |
|
34 |
numbers = new Integer[maxSize]; |
35 |
for (int i = 0; i < maxSize; ++i) |
36 |
numbers[i] = rng.nextInt(128); |
37 |
|
38 |
oneRun(klass, maxSize); |
39 |
Thread.sleep(100); |
40 |
oneRun(klass, maxSize); |
41 |
Thread.sleep(100); |
42 |
oneRun(klass, maxSize); |
43 |
|
44 |
if (total == 0) System.out.print(" "); |
45 |
} |
46 |
|
47 |
static void oneRun(Class klass, int n) throws Exception { |
48 |
Queue<Integer> q = (Queue<Integer>)klass.newInstance(); |
49 |
int sum = total; |
50 |
int m = rng.nextInt(numbers.length); |
51 |
long startTime = System.nanoTime(); |
52 |
for (int k = 0; k < n; ++k) { |
53 |
for (int i = 0; i < k; ++i) { |
54 |
if (m >= numbers.length) |
55 |
m = 0; |
56 |
q.offer(numbers[m++]); |
57 |
} |
58 |
Integer p; |
59 |
while ((p = q.poll()) != null) |
60 |
sum += p.intValue(); |
61 |
} |
62 |
total += sum; |
63 |
long endTime = System.nanoTime(); |
64 |
long time = endTime - startTime; |
65 |
double secs = (double)(time) / 1000000000.0; |
66 |
System.out.println("Time: " + secs); |
67 |
} |
68 |
|
69 |
} |