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Date:      Thu, 16 Dec 1999 00:58:19 +0100 (MET)
From:      Rolf Grossmann <grossman@securitas.net>
To:        freebsd-java@FreeBSD.org
Cc:        java-port@FreeBSD.org
Subject:   Duplicate Class initialization?
Message-ID:  <199912152358.AAA23703@blue.securitas.net>
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--7jGBHTmUit
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Hi all,

I'm having a small problem (what seems to be a bug) with the FreeBSD JDK.
The static initializer for a class is called the first time when that
class is referenced from a third class that is loaded dynamically and
a second time after a socket connection has been accepted and the class
is referenced from the main program. The exact scenario can be seen from
the attached test case. It is the simplest test case I was able to figure
out. It does not happen when you access the Class directly before (or
without) accepting the socket.

To verify the problem, compile the 3 attached classes and run java Main.
You will see the classes being initialized. From another shell, make a
socket connection to port 2222 on that host. Wonder why Class1 is
being initialized again.

The problem does not occur on Solaris, so I guess it's FreeBSD specific.
It also does not happen when using TYA. I'm using the
jdk1.1.8_ELF.V1999-11-9 on FreeBSD 3.3-STABLE (as of 2-3 months ago).

Bye, Rolf

--7jGBHTmUit
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Content-Description: Main.java
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	filename="Main.java"
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import java.lang.Class;
import java.net.*;
import java.io.*;

class Main {
public static void main (String args[]) {
    ServerSocket sock;

    try {
	sock = new ServerSocket(2222);
    } catch(IOException e) {
	System.exit(1);		// Security may prevent exit ...
	return;			// but not return
    }

    try {
	Class.forName("Class2");
    } catch(ClassNotFoundException e) {
    }

    try {
	Socket s = sock.accept();
	Class1.fn();
    } catch(IOException e) {}

}

}

--7jGBHTmUit
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Content-Description: Class1.java
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	filename="Class1.java"
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import java.util.Vector;

class Class1 {
private static Vector v = new Vector();

static {
    System.out.println("Init Class1");
}
    
public static void register(Class2 c) {
    v.addElement(c);
    System.out.println("register");
}

public static void fn() {}

}

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Content-Description: Class2.java
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	filename="Class2.java"
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class Class2 {

static {
    System.out.println("Start Class2");
    Class1.register(new Class2());
    System.out.println("End Class2");
}
    
private Class2() {
}

/* ... */

}

--7jGBHTmUit--


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