On 27/11/14 12:32 AM, DRC wrote: > On 11/26/14 8:52 PM, Nathan Kidd wrote: >> A work-around for other proxies would be to make the faked function >> query the asked-for connection first, and only supply fake information >> if the extension is not found. All the 2D-Xserver GLX queries should be >> checking if GLX is available anyway, and would not occur if the >> extension isn't there. I think this change would push the "we need a >> TLS flag" issue into, if not theoretical, at least unnecessary-for-now >> territory. > > OK, now you lost me. How would your patch prevent the issue from > occurring in an X proxy like TurboVNC that lacks GLX?
Because proxies without GLX will never make the failing queries in the first place. static void buildVisAttribTable(Display *dpy, int screen) _XQueryExtension(dpy, "GLX"...) would have failed, so no __glXGetConfig calls. And in my observation, if((atom=XInternAtom(dpy, "SERVER_OVERLAY_VISUALS", True))!=None) would also fail, so no pass through overlays are possible. (Though I think it would be at least theoretically safer to condition it on GLX also being available .) Because an unknown number of xcb functions that may already be hooked may be called from any other glX/X11/xcb functions, causing the "double fake" situation, I think it is still wise in the long term to pursue the TLS-based flag we discussed before. I don't have a huge fire under me to do it right now, however, since the issue is back to theoretical. > -- Not having a GLX extension serves as an important failsafe for > VirtualGL. That way, if VGL fails, it's pretty obvious that it is > failing, because OpenGL simply won't work. Otherwise, it can produce > some hard-to-diagnose issues in which VGL appears to be working but > things are just running really slowly. The problem is: performance > issues are less likely to be reported as bugs, so this could cause some > serious issues to remain unreported, whereas otherwise they would > manifest as obvious bugs. Tell me about it. +logo has been a watch word around here for a long time. -Nathan ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk _______________________________________________ VirtualGL-Devel mailing list VirtualGL-Devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/virtualgl-devel
