Hi, all.
I found BasePooledObjectFactory.validateObject() of commons-pool
sometimes called
on unexpected timing and I cannot identify the cause.
So I would like to ask some advice.
I've configured the pool so as to the validateObject() would be
invoked only on instance
creation, but sometimes it was invoked for "non-fresh" instance on borrowing.
I also attach small reproduction code below.
Can anyone tell it is because some lack of configurations, or, actual
pool's bug?
Thanks in advance.
----
Noriyuki Torii
----
import java.io.*;
import java.util.*;
import org.apache.commons.pool2.*;
import org.apache.commons.pool2.impl.*;
public class reproduction
{
private static class MyPooledObj
{
volatile int i = 0;
final String uuid = UUID.randomUUID().toString();
}
private static class MyFactory extends BasePooledObjectFactory<MyPooledObj>
{
@Override
public MyPooledObj create() {
return new MyPooledObj();
}
@Override
public PooledObject<MyPooledObj> wrap(MyPooledObj o) {
return new DefaultPooledObject<MyPooledObj>(o);
}
@Override
public boolean validateObject(PooledObject<MyPooledObj> o) {
MyPooledObj myobj = o.getObject();
synchronized (myobj) {
myobj.i++;
}
System.out.println("Validated.");
return true;
}
}
public static void main(String[] args)
throws Exception
{
GenericObjectPoolConfig poolCfg = new GenericObjectPoolConfig() ;
poolCfg.setMaxTotal(1);
poolCfg.setMaxIdle(1);
poolCfg.setBlockWhenExhausted(true);
poolCfg.setMaxWaitMillis(10000);
poolCfg.setTestOnCreate(true); // should be validated only on creation
poolCfg.setTestOnBorrow(false);
poolCfg.setTestOnReturn(false);
poolCfg.setTestWhileIdle(false);
final GenericObjectPool<MyPooledObj> pool =
new GenericObjectPool<MyPooledObj>(new MyFactory(), poolCfg);
final MyPooledObj o = pool.borrowObject();
System.out.printf("%d: %s\n", o.i, o.uuid);
Timer t = new Timer();
t.schedule
(new TimerTask() {
public void run() {
pool.returnObject(o);
}
}, 3000);
// validation will occur again for non-fresh instance,
// confirmed on commons-pool2-2.2 with jdk1.7.0_55
MyPooledObj o2 = pool.borrowObject();
System.out.printf("%d: %s\n", o2.i, o2.uuid);
pool.returnObject(o2);
pool.close();
t.cancel();
}
}
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
