Maximum number of threads in a JVM
Out of curitosity, I thought it would be interesting to know the maximum number of threads I could squeeze out of a JVM on various platforms. From an old thread on Stack Overflow, I knew that different JVM implementations had different limits. So, I whipped up this little Java program and ran it on various platforms.
import java.util.concurrent.atomic.AtomicInteger;
public class ThreadCounter extends Thread {
private static final AtomicInteger count = new AtomicInteger();
public static void main(String[] args) {
while (true)
(new ThreadCounter()).start();
}
@Override
public void run() {
System.out.println(count.incrementAndGet());
while (true)
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
break;
}
}
} javac ThreadCounter.java
java -cp . ThreadCounter
The results:
| Hardware | OS | JVM | Count |
| 2010 i5 MBP, 4GB | OSX 10.6 | Apple 1.6.0_22-b04-307 | 2540 |
| Xeon 5120, 4GB | Debian Lenny 64-bit | Sun 1.6.0_12-b04 | 31618 |
| EC2 m1.small, 1.7GB | Ubuntu 10.04 32-bit | OpenJDK IcedTea6 1.8.2 | 7452 |
| Atom 330, 2GB | Windows XP SP3 | Sun 1.6.0_27-b07 | 5165 |
| EC2 c1.medium, 1.7GB | Ubuntu 10.04 32-bit | OpenJDK IcedTea6 1.8 | 7029 |
Interesting...