Tk_FreeXId(3)

Tk_FreeXId(3)         Tk Library Procedures         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, cur-
                                    sor,  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 iden-
     tifiers  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_GetFont,
     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  do  not  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

Tk                      Last change: 4.0                        1