[prev in list] [next in list] [prev in thread] [next in thread] 

List:       freedesktop-xorg-devel
Subject:    Re: [PATCH:libX11 2/2] Convert XCreate{Pix,	Bit}map...Data to use C99 designated initializers
From:       Alan Coopersmith <alan.coopersmith () oracle ! com>
Date:       2012-06-30 16:36:18
Message-ID: 4FEF2B02.7080600 () oracle ! com
[Download RAW message or body]

On 06/30/12 09:27 AM, walter harms wrote:
> 
> 
> Am 30.06.2012 17:04, schrieb Alan Coopersmith:
>> On 06/30/12 02:38 AM, walter harms wrote:
>>>> -    pix = XCreatePixmap(display, d, width, height, 1);
>>>> -    gc = XCreateGC(display, pix, (unsigned long) 0, (XGCValues *) 0);
>>>> +    Pixmap pix = XCreatePixmap(display, d, width, height, 1);
>>>
>>> if you assume that gc can fail you should check pix also
>>> 	if ( pix == NULL )
>>> 	    return (Pixmap) None;
>>
>> Nope - Xlib doesn't do the same things there, since in Xlib, a GC
>> is a pointer to a struct, while a Pixmap is simply an XID (integer).
>>
>> XCreateGC can return NULL if malloc fails:
>>   http://cgit.freedesktop.org/xorg/lib/libX11/tree/src/CrGC.c#n64
>>
>> XCreatePixamp doesn't malloc, simply returns the next available XID:
>>   http://cgit.freedesktop.org/xorg/lib/libX11/tree/src/CrPixmap.c#n40
>>
> yep,
>  XAllocID(dpy) is the core but can it never fail ?

Not that I'm aware of.

>  according to the man page:
>  "XCreatePixmap can generate BadAlloc, BadDrawable, and BadValue errors."

Those are asynchronous X11 protocol errors that can be generated when the
X server gets around to processing the request that XCreatePixmap puts in
the buffer - they aren't returned directly from XCreatePixmap itself.

-- 
	-Alan Coopersmith-              alan.coopersmith@oracle.com
	 Oracle Solaris Engineering - http://blogs.oracle.com/alanc
_______________________________________________
xorg-devel@lists.x.org: X.Org development
Archives: http://lists.x.org/archives/xorg-devel
Info: http://lists.x.org/mailman/listinfo/xorg-devel
[prev in list] [next in list] [prev in thread] [next in thread]