1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
package org.openslx.util;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Executors;
import java.util.concurrent.RejectedExecutionHandler;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
/**
* Grows to maximum pool size before queueing. See
* http://stackoverflow.com/a/20153234/2043481
*/
public class GrowingThreadPoolExecutor extends ThreadPoolExecutor {
private int userSpecifiedCorePoolSize;
private int taskCount;
/**
* The default rejected execution handler
*/
private static final RejectedExecutionHandler defaultHandler =
new AbortPolicy();
public GrowingThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime,
TimeUnit unit, BlockingQueue<Runnable> workQueue) {
this(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, defaultHandler);
}
public GrowingThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit,
BlockingQueue<Runnable> workQueue, ThreadFactory threadFactory) {
this(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, threadFactory, defaultHandler);
}
public GrowingThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit,
BlockingQueue<Runnable> workQueue, RejectedExecutionHandler handler) {
this(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, Executors.defaultThreadFactory(),
handler);
}
public GrowingThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit,
BlockingQueue<Runnable> workQueue, ThreadFactory threadFactory, RejectedExecutionHandler handler) {
super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, threadFactory, handler);
userSpecifiedCorePoolSize = corePoolSize;
}
@Override
public void execute(Runnable runnable) {
synchronized (this) {
taskCount++;
setCorePoolSizeToTaskCountWithinBounds();
}
super.execute(runnable);
}
@Override
protected void afterExecute(Runnable runnable, Throwable throwable) {
super.afterExecute(runnable, throwable);
synchronized (this) {
taskCount--;
setCorePoolSizeToTaskCountWithinBounds();
}
}
private void setCorePoolSizeToTaskCountWithinBounds() {
int threads = taskCount;
if (threads < userSpecifiedCorePoolSize)
threads = userSpecifiedCorePoolSize;
if (threads > getMaximumPoolSize())
threads = getMaximumPoolSize();
super.setCorePoolSize(threads);
}
public void setCorePoolSize(int corePoolSize) {
synchronized (this) {
userSpecifiedCorePoolSize = corePoolSize;
}
}
@Override
public int getCorePoolSize() {
synchronized (this) {
return userSpecifiedCorePoolSize;
}
}
}
|
