This post is to remind myself that when using Java thread Pool created by java.util.concurrent.ExecutorService to execute amount of threads, there is going to be no execution orders.
The following program is a proof:
package com.threads;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
/**
* Created by daiyan on 8/05/15.
*/
public class SampleThreadPool
{
private ExecutorService threadPools;
SampleThreadPool() throws InterruptedException
{
threadPools = Executors.newFixedThreadPool(50);
for (int i = 0; i < 100; i++)
{
threadPools.submit(new MyThread(i + ""));
}
threadPools.shutdown();
threadPools.awaitTermination(Long.MAX_VALUE, TimeUnit.DAYS);
}
class MyThread implements Runnable {
String message;
MyThread(String message) {
this.message = message;
}
@Override
public void run()
{
System.out.println(Thread.currentThread().getName() + ": " + message );
}
}
public static void main(String[] args) throws InterruptedException
{
SampleThreadPool sampleThreadPool = new SampleThreadPool();
while (!sampleThreadPool.threadPools.isTerminated())
{
}
}
}The result will look like this:
pool-1-thread-1: 0
pool-1-thread-4: 3
pool-1-thread-3: 2
pool-1-thread-2: 1
pool-1-thread-5: 4
pool-1-thread-6: 5
pool-1-thread-7: 6
pool-1-thread-8: 7
pool-1-thread-9: 8
pool-1-thread-10: 9
pool-1-thread-11: 10
pool-1-thread-12: 11
pool-1-thread-13: 12
pool-1-thread-14: 13
pool-1-thread-15: 14
pool-1-thread-16: 15
pool-1-thread-17: 16
pool-1-thread-18: 17
pool-1-thread-19: 18
pool-1-thread-20: 19
pool-1-thread-21: 20
pool-1-thread-22: 21
pool-1-thread-23: 22
pool-1-thread-24: 23
pool-1-thread-25: 24
pool-1-thread-26: 25
pool-1-thread-27: 26
pool-1-thread-28: 27
pool-1-thread-29: 28
pool-1-thread-30: 29
pool-1-thread-31: 30
pool-1-thread-32: 31
pool-1-thread-33: 32
pool-1-thread-34: 33
pool-1-thread-35: 34
pool-1-thread-36: 35
pool-1-thread-37: 36
pool-1-thread-38: 37
pool-1-thread-39: 38
pool-1-thread-40: 39
pool-1-thread-41: 40
pool-1-thread-42: 41
pool-1-thread-43: 42
pool-1-thread-44: 43
pool-1-thread-45: 44
pool-1-thread-46: 45
pool-1-thread-47: 46
pool-1-thread-48: 47
pool-1-thread-49: 48
pool-1-thread-50: 49
pool-1-thread-1: 50
pool-1-thread-4: 51
pool-1-thread-2: 54
pool-1-thread-50: 53
pool-1-thread-1: 52
pool-1-thread-8: 62
pool-1-thread-50: 61
pool-1-thread-3: 60
pool-1-thread-7: 59
pool-1-thread-2: 58
pool-1-thread-6: 57
pool-1-thread-5: 55
pool-1-thread-4: 56
pool-1-thread-5: 70
pool-1-thread-6: 69
pool-1-thread-2: 68
pool-1-thread-6: 73
pool-1-thread-7: 67
pool-1-thread-3: 66
pool-1-thread-50: 65
pool-1-thread-8: 64
pool-1-thread-1: 63
pool-1-thread-8: 79
pool-1-thread-50: 78
pool-1-thread-3: 77
pool-1-thread-7: 76
pool-1-thread-6: 75
pool-1-thread-2: 74
pool-1-thread-5: 72
pool-1-thread-4: 71
pool-1-thread-5: 87
pool-1-thread-2: 86
pool-1-thread-6: 85
pool-1-thread-7: 84
pool-1-thread-3: 83
pool-1-thread-50: 82
pool-1-thread-8: 81
pool-1-thread-8: 95
pool-1-thread-1: 80
pool-1-thread-8: 96
pool-1-thread-50: 94
pool-1-thread-3: 93
pool-1-thread-7: 92
pool-1-thread-6: 91
pool-1-thread-2: 90
pool-1-thread-5: 89
pool-1-thread-4: 88
pool-1-thread-50: 99
pool-1-thread-8: 98
pool-1-thread-1: 97