Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!snorkelwacker!bloom-beacon!viking.UUCP!dpb
From: dpb@viking.UUCP (Don Bennett           433-3311, 408)
Newsgroups: comp.windows.x
Subject: Re: Motif XtDestroyWidget problem!
Message-ID: <9005282211.AA10524@viking.frame.com>
Date: 28 May 90 22:11:39 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 34


> XtDestroyWidget does not seem to work properly with Motif. For one thing
> Motif uses amazing amounts of memory for widgets; create a bulletin
> board with one button and 10 text widgets; you have used over 100K of memory
> (in Ultrix)! What is even worse is that you cannot seem to free this space!
> In a simple program where you create and destroy this set, each increment
> causes a memory leak of 66K. Has anybody else encountered this problem?
> The same problem occurs on Sparc's as well so it is not platform dependent.
> XtUnrealizeWidget or even trying to destory each child widget does not solve
> the problem. This makes the toolkit unusable in large applications. I have
> a complicated window with over 100 widgets and it allocates 2M of memory
> compared to DECwindows' 100K (at least DECwindows frees properly). Here is
> the sample code (when you press the main button, it should create and free
> a bulletin board):

The problem is not in Motif, it is a bug in the R3 intrinsics.

XtInstallAccelerators() merges the bulletin-board accelerators
into the translations of each of its children, and this merged table
is never freed. My fix was to:
(a) clear the source widget in the action record,
(b) cache the merged table,
(c) record the source widget in an application context,
(d) modify _XtTranslateEvent() to find the source widget in 
    the application context if necessary;
(e) Delete the context record when the destination widget is
    destroyed.

I'll send you the fix I use if you drop me a line.
No guarentees, but it works for me.

   Don Bennett           (408)433-3311
   dpb@frame.com
   Frame Technology