Discussions related to Visual Prolog
Martin Meyer
VIP Member
Posts: 298
Joined: 14 Nov 2002 0:01

Variables Pending in Debugger Window

Unread post by Martin Meyer »

Hello Thomas,

when I am running the debugger I often see lines of the form "<Variable> pending..." in the Variables in the Current Clause window:

Variables in the Current Clause.jpg
Variables in the Current Clause.jpg (50.33 KiB) Viewed 946 times

It seems it happens randomly. But, once it has happened, it tends to be sticky. I.e. when I am going on stepping through the code, the display of the variable's values stays to be pending.

Is there a way how I can prevent displays being pending?
Regards Martin
User avatar
Thomas Linder Puls
VIP Member
Posts: 1245
Joined: 28 Feb 2000 0:01

Re: Variables Pending in Debugger Window

Unread post by Thomas Linder Puls »

Hi, Martin.

It has to do with a locked critical section. It is an unfortunate possibility after we have switched to "presenters". The debugger needs access to this critical section, but it can be locked by your program (which is unfortunately also braked). We use certain "tricks" to come out of this deadlock, but in your case it seems inadequate.

Can you send a Help -> Send Bug Report ... from the IDE when it happens (you can fx. write "Pending variables" in the comment field? That will give us some information to look at.

Does your program use multiple threads?
Regards Thomas Linder Puls
PDC
Martin Meyer
VIP Member
Posts: 298
Joined: 14 Nov 2002 0:01

Re: Variables Pending in Debugger Window

Unread post by Martin Meyer »

No, it does not use multiple threads. At least not in 'my' code. I am not sure whether there is some pfc predicate, which I am calling in my program, that internally makes use of multiple threading.
Regards Martin
Martin Meyer
VIP Member
Posts: 298
Joined: 14 Nov 2002 0:01

Re: Variables Pending in Debugger Window

Unread post by Martin Meyer »

I have sent a bug report from the IDE with comment "Pending variables".
Regards Martin
Martin Meyer
VIP Member
Posts: 298
Joined: 14 Nov 2002 0:01

Re: Variables Pending in Debugger Window

Unread post by Martin Meyer »

When I have sent the bug report, the Variables in the Current Clause was:

Variables in the Current Clause 2.jpg
Variables in the Current Clause 2.jpg (54.63 KiB) Viewed 915 times
Regards Martin
Martin Meyer
VIP Member
Posts: 298
Joined: 14 Nov 2002 0:01

Re: Variables Pending in Debugger Window

Unread post by Martin Meyer »

It seems pending variables do not appear that randomly as I told before. At certain places in my code the effect arises very likely, but at others never.
Regards Martin
User avatar
Thomas Linder Puls
VIP Member
Posts: 1245
Joined: 28 Feb 2000 0:01

Re: Variables Pending in Debugger Window

Unread post by Thomas Linder Puls »

Thank you, we will look at it.
Regards Thomas Linder Puls
PDC
Post Reply