X Testing Software

This page provides infomation on various tools to aid the testing ( and to a degree, debugging ) of X Servers and Clients.

Please add anything I've missed that you find useful.

General Testing/Debugging Tools ( Not X specific )


GNU interactive debugger.


gcov, gprof

Code coverage and profiling. Part of the GCC compiler collection.



Valgrind is a GPL'd system for debugging and profiling x86-Linux ( and now powerpc ? ) programs. Very useful for trapping memory leaks.


X Server Testing


EricAnholt 's program for testing server render acceleration correctness. In initial development, available from fd.o git "xapps/rendercheck/"

Xtest suite

Build and usage instructions can be found here: http://wiki.x.org/wiki/XorgTesting


Tests performance of most ( non render ext ) X operations.

Available packaged in most distributions.


I did some tests measuring blit speeds with kdrive on various ARM based handhelds. The results of which are available here;


X Client Testing

Client X servers ( or X clients that are servers )

Xephyr, Xnest

                 * Both of these provide servers that run on an existing X server. Useful for window manager development or 'emulation' of a different sized display. Both are available in <a href="../../Infrastructure/git/Users/">git</a>. Xnest is mature and stable but lacks support for 'modern' X extensions ( such as render and composite ), whilst Xephyr supports these extensions but is a newer and less widely distributed application. 
                    * <a href="http://cgit.freedesktop.org/xorg/xserver/tree/hw/xnest">Xnest</a> 
                    * <a href="http://cgit.freedesktop.org/xorg/xserver/tree/hw/kdrive/ephyr">Xephyr</a> Xnest is also available packaged in most distributions. 

See also Software/Xephyr

Server side resource leaks


                 * Provides realtime 'top' like statistics of each clients resource usage in the server. <a href="../xrestop/">Software/xrestop</a> 

EWMH/ICCCM compliance

Window manager tools.

                 * matchbox & metacity window manager source both contain various tools to generate 'dummy' windows with particular properties. 
                       * <a href="http://matchbox.handhelds.org">http://matchbox.handhelds.org</a> ( grab matchbox-tests ) <a href="http://ftp.gnome.org/pub/gnome/sources/metacity/">http://ftp.gnome.org/pub/gnome/sources/metacity/</a> 


                       * Command line tool to inspect window properties. Available packaged for most distributions. 


                       * New nice window inspection tool with GTK GUI and EWMH hint 'aware'. <a href="../wininfo/">Software/wininfo</a> 

Protocol usage / events


                    * xev displays the contents on events recieved by its window. Available packaged for most distributions. 


                    * xmon is an 'interactive X protocol monitor'. It acts as a proxy between a server and clients and provides configurable infomation on the traffic passing through it. Available packaged for most distributions. ( apt-get install xmon on Debian ) 

Also see

                    * Keith Packards 'X Window System Network Performance' paper; <a href="http://freedesktop.org/~keithp/talks/usenix2003/html/net.html">http://freedesktop.org/~keithp/talks/usenix2003/html/net.html</a> Kenton Lees 'Debugging X Input Events'; <a href="http://www.rahul.net/kenton/events.html">http://www.rahul.net/kenton/events.html</a> 

Automating Usage


                    * Xnee is a suite of programs that can record and replay X events. This allows user interaction to be recorded and played back. Xnee can be used as a monitor, to 'retype' a file and to distribute events. Xnee can record all data in the X11 protocol. <a href="http://www.sandklef.com/xnee/">http://www.sandklef.com/xnee/</a> 



                       * 'matchbox nest' is a graphical wrapper around xnest. Its intended for embedded developers that want to simulate a target device ( with display, buttons ) on a desktop machine. <a href="http://matchbox.handhelds.org/sources/matchbox-nest/">http://matchbox.handhelds.org/sources/matchbox-nest/</a> 

-- ?MatthewAllum - 09 Jun 2004