Name: dbT83986 Date: 05/30/99


I have been trying to install jdk1.2.1 (and I've tried 1.2) as a pluggable VM in
VisualCafe. So far I have failed to "Step-Into" a program. In trying to get things
to work I have uninstalled VisualCafe and all previously installed JDKs (and
cleaned out the JavaSoft registry entries) and 'clean' installed JDK 1.2.

I have not been able to get JDB to locally on my Win 95 portable. I have since
reinstalled VisualCafe aswell. The transcript below shows the results of two
attempts to run JDB, firstly using the java environment installed by VisualCafe,
which works as expected, and secondly by invoking \jdk1.2\bin\jdb
to force the JDK 1.2 version to run. This second invocation pauses for a long
while before emitting the "[debugger....]" message and then hangs around
doing nothing. CTL-C is require to get the command prompt back.

[Start of Transcript]
C:\USERS\SKW\Java>set CLASSPATH=

C:\USERS\SKW\Java>jdb -dbgtrace Play
Symantec Java! JustInTime Compiler Version 3.10.107(i) for JDK 1.1.x
Copyright (C) 1996-99 Symantec Corporation

Initializing jdb...
[debugger: starting child: C:\VISUAL~1\JAVA\BIN\JAVA_G.EXE -debug -debugport -1
-ms16m -Djava.compiler=NONE symantec.tools.debug.EmptyApp]
[debugger: connected]
[debugger: connected to Symantec debug VM or runtime]
[debugger: loading classes ...]
[debugger: reading 75 classes...]
0xe9d528:class(Play)
> exit
[debugger: close(true)]

C:\USERS\SKW\Java>\jdk1.2\bin\jdb -dbgtrace Play
Initializing jdb...
[debugger: starting child: C:\JDK1.2\JRE\bin\java -Xdebug -Djava.compiler=NONE
-Xbootclasspath/a:C:\JDK1.2\lib\tools.jar sun.tools.agent.EmptyApp]
[debugger: password returned: [Internal debug-agent error: **Failed to create po
rt]
]
java.lang.NullPointerException
        at sun.tools.agent.Agent.run(Agent.java:324)
        at java.lang.Thread.run(Thread.java:479)
Failed accessing debugging session on obskw.hpl.hp.com: invalid password.

C:\USERS\SKW\Java>
[End of Transcript]

I have also tried running jdk1.2 java.exe in debug mode with similar results:

[Start of Transcript]
C:\USERS\SKW\Java>\jdk1.2\bin\java -Xdebug -Djava.compiler=NONE -Xbootclasspath/
a:c:\jdk1.2\lib\tools.jar sun.tools.agent.EmptyApp
[Internal debug-agent error: **Failed to create port
]
java.lang.NullPointerException
        at sun.tools.agent.Agent.run(Agent.java:324)
        at java.lang.Thread.run(Thread.java:479)

C:\USERS\SKW\Java>
[End of Transcript]

Whereas extract the corresponding fragment from the Symantec supplied jdb
invocation yields the expected password etc.

[Start of Transcript]
C:\USERS\SKW\Java>java_g -debug -debugport -1 -ms16m -Djava.compiler=NONE symant
ec.tools.debug.EmptyApp
Agent password=/$$VEDbgLocalComm$localhost$channel$$42243

C:\USERS\SKW\Java>
[End of Transcript]

This failure occurs with the ubiqitous "Hello World" program and it is evident that it occurs
before the JVM ever gets to try executing the intended class file (hence no code sample).

This problem was reported on Deja sometime ago without response. I have tried to contact the person that submitted the problem then to see if they managed to get past it... no response as yet.

[Extract from News Thread]
Subject: Debugger hangs
Date: 1998/10/20
Author: Steven C. Bond <###@###.###>
   Posting History
 
I invoked jdb with the following:
 
jdb -dbgtrace -classpath <classpath> filename
Initializing jdb...
 
[debugger: starting child c:\jdk1.2beta4\jre\bin\java -
Xdebug -DJava.compiler=NONE -classpath
<classpath> -Xsysclasspath/a:C\JDK1.2BETA4\lib\tools.jar
sun.tools.agent.EmptyApp]
[debugger: password returned: [Internal debug-agent error: **Failed to create port]]
Failed accessing debugging session on dg3.gestalt-tech.com: invalid password.
 
java.lang.NullPointerException
at sun.tools.agent.Agent.run(Agent.java:318)
at java.lang.Thread.run(Thread.java:475)
 
... and then it hangs
 
This only happens on one particular machine. Other machines in the area
don't have this
problem. What do I need to change on the machine to get past this
 
[End of News Extract]

Things that have occurred to me a possible contributing factors:

1) Windows 95 Networking :-)

2) I'm using a portable whose address is dynamically configured. Currently it is
on 15.144.91.165 (dhcp-91-165.hpl.hp.com). However, the hostname is reported,
as configured in the TCP/DNS setup panel, as obskw.hpl.hp.com which itself
resolves to the (different) IP address that I get when I dial-in. I did try
reconfiguring the hostname to dhcp-91-165 but this did not solve the problem.




3) I am not aways connected to the network.

I've just about run out of things to try and I have very little hair left.

Any help greatfully received.

Thanks

Stuart Williams
HP Labs, Bristol, UK.
Tel: +44 117 3128285
(Review ID: 83618)
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