Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!infonode!doyled.b23b.ingr!doyle
From: doyle@doyled.b23b.ingr (Doyle C. Davidson)
Newsgroups: comp.windows.x
Subject: Xt Resource Cache Counting
Keywords: Xt resources
Message-ID: <1991Jun27.213802.28113@infonode.ingr.com>
Date: 27 Jun 91 21:38:02 GMT
Sender: usenet@infonode.ingr.com (Usenet Administrator)
Reply-To: doyle@doyled.b23b.ingr.com
Organization: Intergraph Corporation - Third Party Software
Lines: 35

Regarding resource cache counting:

Say I have a widget of class fooClass with an XtNforeground resource.

Suppose I want to change the foreground color (let's say I want to
blink the widget) so I get an alternate color via:

    XtConvertAndStore(w, XtRString, &src, XtRPixel, &dest);

Xt adds a XtNdestroyCallback to the widget to decrement the
resource's reference count and free the cached resource if zero.
Right?

To use the same color for a second widget, I must then call
XtConvertAndStore again if I want to properly maintain the
resource cache count.  Correct?

Because, if I don't, and I destroy the first widget (the one
used in the XtConvertAndStore) my reference count could
possible reach zero even though the second widget still
may use that secondary pixel value.

Doyle 
    "I fear explanations explanatory of things explained." -- unknown
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