Tk_FreeXId(3) Tk (4.0) Tk_FreeXId(3)
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NAME
Tk_FreeXId - make X resource identifier available for reuse
SYNOPSIS
#include <tk.h>
Tk_FreeXId(display, id)
ARGUMENTS
Display *display (in) Display for which id was
allocated.
XID id (in) Identifier of X resource
(window, font, pixmap,
cursor, graphics context, or
colormap) that is no longer
in use.
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DESCRIPTION
The default allocator for resource identifiers provided by
Xlib is very simple-minded and does not allow resource
identifiers to be re-used. If a long-running application
reaches the end of the resource id space, it will generate
an X protocol error and crash. Tk replaces the default id
allocator with its own allocator, which allows identifiers
to be reused. In order for this to work, Tk_FreeXId must be
called to tell the allocator about resources that have been
freed. Tk automatically calls Tk_FreeXId whenever it frees
a resource, so if you use procedures like Tk_GetFontStruct,
Tk_GetGC, and Tk_GetPixmap then you need not call
Tk_FreeXId. However, if you allocate resources directly
from Xlib, for example by calling XCreatePixmap, then you
should call Tk_FreeXId when you call the corresponding Xlib
free procedure, such as XFreePixmap. If you don't call
Tk_FreeXId then the resource identifier will be lost, which
could cause problems if the application runs long enough to
lose all of the available identifiers.
KEYWORDS
resource identifier
Page 1 (printed 2/26/99)
