[Xcb] poll_for_event: Assestion

Uli Schlachter psychon at znc.in
Thu Apr 19 23:57:40 PDT 2012


On 20.04.2012 02:48, Louis Mendoza wrote:
> I am new to xcb and I am having a little trouble using xcb_xv_put_image. I am using a Java awt for the user interface and want to put images onto the 
> display object using xcb_xv_put_image. I am able to put images onto the display, but sometimes it randomly crashes and displays this assertion:
> java: ../../src/xcb_io.c:221: poll_for_event: Assertion `(((long) (event_sequence) - (long) (dpy->request)) <= 0)' failed.
> Moving the mouse on top of the image or resized the window seems to aggravate
the problem. Could some one please help me out. Any help will be greatly

The file xcb_io.c isn't in libxcb, but in libX11. This assertion was added in
commit 933aee1d5c53b0cc7 (part of release 1.3.4) and was replaced in commit
761b8aa0c9b3c58c478ac (part of release 1.4.4). So your version of libX11 must be
somewhere in between. Also, I can tell you that this is a race between threads.
However, I don't know much more than this, sorry.

So the important part: Not a problem in xcb.

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