[Xcb] async reply error questions

Barton C Massey bart at cs.pdx.edu
Thu May 19 10:59:30 PDT 2005


Looks like a problem. As near as I can tell, though, it's an
Xlib+Mozilla+threading problem, not an XCB problem, so we
probably aren't going to be able to be too helpful on this
list.  Sorry!

	Bart Massey
	bart at cs.pdx.edu

In message <1116507327.3076.150.camel at zaphod> you wrote:
> Hi,
> 
> I try to fetch the names of open windows from within mozilla firefox.
> 
> I tried 2 approaches, one beeing a mozilla XPROM component,
> the other a standalone executeable started from within mozilla.
> 
> My Programming against xlib does basically:
>   display =3D XOpenDisplay(NULL);
>   findWindowRecursive(DefaultRootWindow(display), windowname);
>     where findWindowRecursive recursively does:
>       XFetchName()
>       XQueryTree()
>       (until the requested window name is found.)
>   XCloseDisplay(display)
>   =20
> I tried multiple variations of using XSynchronize(), XSync()
> XLockDisplay() around my code and i tried XInitThreads(), all with no
> success.
> 
> Some calls to X work, then randomly Mozilla receives a X Error
> 'Unexpected Async Reply' or, more seldomly 'Bad Window'.
> 
> When i put my xlib calls into a standalone executeable, it works fine,
> but also fails if i launch the exe from within mozilla with nsIProcess
> which actually does execve().
> 
> I could agree with google's results that this is some sort of
> threading-race condition, (altough I seem to access X only readonly) but
> this won't explain why a freshly fork'd process produces the same
> results.
> 
> 
> I'd appreciate any hints,
> 
> thanks,
> 
>  / Karl


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