tcljava-dev

[tcljava-dev] TclBlend Core Dump

[Bruce C. <bru...@ya...>]

Thank you for your response and willingness to help.

I have this problem in a very small box. 

Behavior:

When making a Tcl "package" and a command extension using an outside SNMP implementation, the command causes a core dump. The same implementation in JACL works fine. I reduced the problem to a few dependencies in the Java made package. They are:

Use the package command in Java

Throw an exception



Files:

Filename: PTLCommands.java

import tcl.lang.*; 

public class PTLCommands extends Extension {

public void init(Interp interp) {

interp.createCommand("sayhello", new SayhelloCmd());

}

}

Filename: SayhelloCmd.java

import tcl.lang.*;

import snmp.*;

class SayhelloCmd implements Command {

public void cmdProc(Interp interp, TclObject argv[]) {

try {

SNMPsample comInterface = new SNMPsample();

}

catch(Exception e) {

}

}

}

Filename: SNMPsample.java

package snmp;

import java.net.*;

public class SNMPsample {

public SNMPsample() 

throws SocketException {

}

}

Filename: a.tcl

package require java

java::load -classpath . PTLCommands

Steps:

Get to the tclsh prompt

%source a.tcl

%exit

A core dump is produced. I suspect that the Tcl package command and the Java package command are conflicting. I am under the impression that the TclBlend environment allows for Java and tcl commands to co-exist.


		
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Re: [tcljava-dev] TclBlend Core Dump

[Mo D. <md...@un...>]

On Wed, 25 Aug 2004 14:06:25 -0700 (PDT)
Bruce Chidester <bru...@ya...> wrote:

> 
> Thank you for your response and willingness to help.
> 
> I have this problem in a very small box. 
> 
> Behavior:
> 
> When making a Tcl "package" and a command extension using an outside SNMP implementation, the command causes a core dump. The same implementation in JACL works fine. I reduced the problem to a few dependencies in the Java made package. They are:

Here is the crash I got when I tried your example:

Exception in thread "main" java.lang.NoClassDefFoundError: snmp/SNMPsample
JavaCmdProc : unexpected pending exception
SIGABRT 6 (*) abort process
        stackpointer=0xbfffe48c

Full thread dump Classic VM (J2RE 1.3.0 IBM build cxdev-20000502, native threads):
    "Finalizer" (TID:0x40408708, sys_thread_t:0x829a9d0, state:CW, native ID:0x1005) prio=8


The problem in this example is that the class should be defined in a dir named snmp
not in the same dir. I assume you built with "javac *.java" and it put the class files
in the current dir.

You can work around the crash like so:

% javac -d tmp PTLCommands.java SayhelloCmd.java SNMPsample.java
% find tmp
tmp
tmp/PTLCommands.class
tmp/SayhelloCmd.class
tmp/snmp
tmp/snmp/SNMPsample.class

Then change the a.tcl file to:

java::load -classpath tmp PTLCommands

That should avoid the crash, getting the code to not crash in the first place
is another issue, one that I will have to look into more.

cheers
Mo