Name: nt126004 Date: 09/18/2001


java version "1.3.1_01"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.1_01)
Java HotSpot(TM) Client VM (build 1.3.1_01, mixed mode)

It seems that ObjectOutputStream has some kind of memory leak, which causes
programs that uses it intensively to fail.
Here is little example that provides more explanation:

[javacode]
import java.net.*;
import java.io.*;

public class OutOfMemoryIssue implements Runnable
{
Socket clientside;
static final int m_Size = 300000;
public static void main(String[] args) {
try
{
ServerSocket server = new ServerSocket(17000);
Thread connector = new Thread(new OutOfMemoryIssue());
connector.start();
Socket serverside = server.accept();
// InputStream is = serverside.getInputStream();
ObjectInputStream is = new ObjectInputStream
(serverside.getInputStream());
int i = 0;
byte[] data = new byte[m_Size];
try
{
while(true)
{
// is.read(data);
data = (byte[])is.readObject();
i++;
}
}
catch (Exception ex)
{
System.out.println("exc:"+ex);
System.out.println("exited at:"+i);
}
connector.join();
is.close();
serverside.close();
server.close();
}
catch(Exception ex)
{
System.out.println(ex);
ex.printStackTrace();
}
}

public void run()
{
// only for connecting to the server
// OutputStream os = null;
ObjectOutputStream os = null;
int i = 0;
try
{
clientside = new Socket("localhost", 17000);
// os = new clientside.getOutputStream();
os = new ObjectOutputStream(clientside.getOutputStream
());

Thread.sleep(1000);
while(true)
{
// os.write(new byte[m_Size]);
os.writeObject(new byte[m_Size]);
i++;
}
}
catch(Exception ex)
{
System.out.println("exc:"+ex);
}
catch(OutOfMemoryError er)
{
System.out.println("exc:"+er);
}
System.out.println("run() exited at:"+i);

try
{
os.close();
clientside.close();
}
catch (IOException ex)
{
}
}
}
[/javacode]

it creates a socket pair and a thread, that writes till some exception
(OutOfMemoryError) happened.

So here is output it produces on my computer:
[javacode]
exc:java.lang.OutOfMemoryError
run() exited at:110
exc:java.io.EOFException: Expecting code
exited at:110
[/javacode]
It means that while loop executed 110 times and … BUM :)
  Interesting that if I use standard write/read (even of
ObjectOutputStream/ObjectInputStream) pair instead of writeObject/readObject,
nothing terrible happens (no memory leaks etc).

Please let me know if I do something wrong.

Thank you in advance,
Alexey.
(Review ID: 132121)
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