'\"
'\" Copyright (c) 1990 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: FreeXId.3,v 1.4 1999/04/21 21:53:21 rjohnson Exp $
'\" 
.so man.macros
.TH Tk_FreeXId 3 4.0 Tk "Tk Library Procedures"
.BS
.SH NAME
Tk_FreeXId \- make X resource identifier available for reuse
.SH SYNOPSIS
.nf
\fB#include <tk.h>\fR
.sp
\fBTk_FreeXId(\fIdisplay, id\fB)\fR
.SH ARGUMENTS
.AS Display *display out
.AP Display *display in
Display for which \fIid\fR was allocated.
.AP XID id in
Identifier of X resource (window, font, pixmap, cursor, graphics
context, or colormap) that is no longer in use.
.BE

.SH DESCRIPTION
.PP
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, \fBTk_FreeXId\fR must be called to
tell the allocator about resources that have been freed.
Tk automatically calls \fBTk_FreeXId\fR whenever it frees a
resource, so if you use procedures like \fBTk_GetFont\fR,
\fBTk_GetGC\fR, and \fBTk_GetPixmap\fR then you need not call
\fBTk_FreeXId\fR.
However, if you allocate resources directly from Xlib, for example
by calling \fBXCreatePixmap\fR, then you should call \fBTk_FreeXId\fR
when you call the corresponding Xlib free procedure, such as
\fBXFreePixmap\fR.
If you don't call \fBTk_FreeXId\fR then the resource identifier will
be lost, which could cause problems if the application runs long enough
to lose all of the available identifiers.

.SH KEYWORDS
resource identifier
