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@tgkprog
Created March 9, 2015 08:15
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Memory - function lcoals - get cleaned up?
package test;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
/**
Run with param 1 and 2 or change type to "2" and "1"
Available memory changes, used jconsole to change force garbage collection.
See video https://www.youtube.com/watch?v=MadBdryX8uk
*/
public class ObjectLife {
public static void main(String[] args) {
// simple multi thread to mimic web app
// ThreadPoolExecutor pool = new ThreadPoolExecutor(5, 3, 110, null, null);
Executor pool = Executors.newFixedThreadPool(3);
String type = "1";
if (args.length > 0) {
type = args[0];
}
Work w = null;
if ("1".equals(type)) {
w = new Worker();
} else {
w = new Worker2();
}
w.init(2);
System.out.println("w type " + w.getClass().getName());
Watch.me.print();
pool.execute(w);
pool.execute(Watch.me);
}
}
class Watch implements Runnable {
long prev = 0;
static Watch me = new Watch();
@Override
public void run() {
while (true) {
try {
Thread.sleep(1100);
} catch (InterruptedException e) {
System.out.println("Intrpt thread " + e);
}
print();
}
}
public void print() {
Runtime r = Runtime.getRuntime();
long free = r.freeMemory();
System.out.println("Free " + free + ", delta " + (free - prev));
System.out.println(", av " + r.maxMemory());
prev = free;
}
}
class Work implements Runnable {
double val = 0;
double val3 = 0;
public void init(double val) {
this.val = val;
}
void do2() {
}
@Override
public void run() {
int cnt = 0;
while (++cnt < 175) {
do2();
try {
Thread.sleep(100);
} catch (InterruptedException e) {
System.out.println("Intrpt thread " + e);
}
}
System.gc();
System.out.println("Type, v3, : " + this.getClass().getName());
Watch.me.print();
}
}
class Worker extends Work {
public void do2() {
double local = ++val;
double local2 = local * 2;
System.out.println(" local " + local + " double " + local2);
val3 = local2 + 1;
}
}
class Worker2 extends Work {
public void do2() {
System.out.println(" local " + ++val + " double " + (val * 2));
val3 = (val * 2) + 1;
}
}
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