<div dir="ltr"> <div class="gmail_extra"> <div class="gmail_quote">On Fri, Nov 3, 2017 at 2:33 AM, Pekka Paalanen <<a href="mailto:ppaalanen@gmail.com" target="_blank">ppaalanen@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On Thu, 2 Nov 2017 10:07:28 -0500 Matt Hoosier <<a href="mailto:matt.hoosier@gmail.com">matt.hoosier@gmail.com</a>> wrote: > On Thu, Nov 2, 2017 at 3:36 AM, Pekka Paalanen <<a href="mailto:ppaalanen@gmail.com">ppaalanen@gmail.com</a>> wrote: > > > On Wed, 1 Nov 2017 13:44:50 -0500 > > Matt Hoosier <<a href="mailto:matt.hoosier@gmail.com">matt.hoosier@gmail.com</a>> wrote: > > > > > > > > I'd like to call attention to another difficult point in using Wayland > > for > > > a device that acts more like a smartphone than a desktop: the main logic > > in > > > wl_display_connect() always attempts to contact a server socket living at > > > ${XDG_RUNTIME_DIR}/${WAYLAND_DISPLAY}. Hi, I rewrote the subject with the hope to raise more interest, being more specific to the proposals. > > I can also imagine that it may not be feasible to create > > application-user specific sockets for everything, so there could be a > > need for a common socket file somewhere that is not tied to > > XDG_RUNTIME_DIR. With a good justification written down, I suspect that > > would be fine. We just need to figure out the details on how to do that > > exactly. > > > > Modifying the meaning of WAYLAND_DISPLAY environment variable to > > support also absolute paths has been proposed before IIRC. Maybe > > resurrecting that work could be a way forward? Can anyone see a problem > > with that? > > > > This would definitely work, so I don't object if this is the preference of > other reviewers. I would prefer (for the reasons coming below) the > /run/wayland/$WAYLAND_DISPLAY suggestion though. > > One note about this: this would contain a subtle change in behavior to > existing users of $WAYLAND_DISPLAY. If somebody sets > WAYLAND_DISPLAY="/wayland-0" currently, this works okay. The concatenation > logic in wl_display_connect() results in a string > "/run/user/<uid>//wayland-0", which is valid despite the duplicate '/'. If > $WAYLAND_DISPLAY is now examined for absolute-pathiness, the logic would > probably see "/wayland-0" as an absolute path reference, and the connection > attempt would fail. While this is true, I don't think it is a blocker unless we find out about tools or compositors doing so. > > > > The suggestion to automatically look for a fallback socket > > at /run/wayland/$WAYLAND_DISPLAY with WAYLAND_DISPLAY defaulting to > > "wayland-0" sounds reasonable to me, but I wouldn't feel comfortable > > making that review decision alone. I do know some people are eager to > > avoid mandatory environment variables if something can be found by > > convention. > > > > This would be my preference. The fewer tweaks to environment variables are > required, the better in my opinion. Right, so there is interest to both ideas, and I don't see them as mutually exclusive. I believe one can also write a good justification for each, so now I'd be looking for reasons why either might be unwanted and acks for each, so that we get enough buy-in to "bless" the behavioural change in libwayland-client. People, give your acks/nacks for the two ideas, please: - modify WAYLAND_DISPLAY to support absolute paths which overrides any search paths </blockquote><div> </div><div>Ack</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> - when the current socket search fails, add one more place to look in: /run/wayland/$WAYLAND_DISPLAY with the default "wayland-0" if WAYLAND_DISPLAY is not set. </blockquote><div> </div><div>Ack</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> The last proposed patch for absolute paths is probably <a href="https://lists.freedesktop.org/archives/wayland-devel/2015-August/023838.html" rel="noreferrer" target="_blank">https://lists.freedesktop.org/archives/wayland-devel/2015-August/023838.html</a> which looks like it got ignored mostly because of a damaged submission and mixed-up (nowadays probably unwanted) server-side changes. The patch also lacks the rationale and justification in the commit message. This is FYI for anyone wanting to carry on that work. Thanks, pq </blockquote></div> </div></div>