scott@spectra.com (Tim Scott) (05/23/91)
I would like any information anyone would be kind enough to provide
on Shared X or any other real-time window-sharing systems that run under
X (xmx, shX, etc.) I'm also interested to know whether there are any
commercial/supported implementations of such a thing.
Thanks for your help.
Tim Scott
9707 Waples St., San Diego CA 92121 P.O. Box 19278, San Diego 92159
scott@spectra.com ...{ucsd!}nosc!spectra!scott AppleLink: SCOTT.T
AOL: TimS45 <<As above, so below>> USA+619-587-6834garfinkel@hpfcso.FC.HP.COM (Dan Garfinkel) (05/23/91)
> I would like any information anyone would be kind enough to provide > on Shared X or any other real-time window-sharing systems that run under > X (xmx, shX, etc.) I'm also interested to know whether there are any > commercial/supported implementations of such a thing. Yes, HP SharedX is now a commercial and supported product available from HP. See the note in comp.windows.x.announce for a copy of the product announcement. -Dan
scott@spectra.com (Tim Scott) (05/23/91)
In article <1991May22.211831.5912@spectra.com> scott@spectra.com (Tim Scott) writes: >I would like any information anyone would be kind enough to provide >on Shared X or any other real-time window-sharing systems that run under >X (xmx, shX, etc.) I'm also interested to know whether there are any >commercial/supported implementations of such a thing. > >Thanks for your help. > >Tim Scott I am always amazed at the generosity and helpfulness of so many people on Usenet. Thanks to everyone who sent me info about xmx, Shared X, and many other projects. Also thanks for not chiding me for not reading the FAQ postings. I did this as an afterthought and found a useful reference at question 76. Still sorting through what everyone sent me. If anyone is interested I will assemble a report and mail to you. email me at scott@spectra.com.
iansmith@dali.cc.gatech.edu (Ian Smith) (05/24/91)
In article <7320020@hpfcso.FC.HP.COM>, garfinkel@hpfcso.FC.HP.COM (Dan Garfinkel) writes: |> > I would like any information anyone would be kind enough to provide |> > on Shared X or any other real-time window-sharing systems that run under |> > X (xmx, shX, etc.) I'm also interested to know whether there are any |> > commercial/supported implementations of such a thing. |> |> Yes, HP SharedX is now a commercial and supported product available from |> HP. See the note in comp.windows.x.announce for a copy of the product |> announcement. |> |> -Dan Hm. I wonder how you system addresses a couple of my issues with window sharing in X: 1) How does it handle heterogenous visual classes? Can I run a shared session on monochrome and color workstation simultaneously? If so, what visual class does the shared window system present to clients? 2) How does it handle window management contention? If it shares "windows" and not "workstations" how do you avoid local copies of the applications having dissimilar sizes? If you try to enforce the same sizes on all copies, how do you avoid race conditions and potential "oscillations" that cant be stopped? 3) What about cut and paste? Does it have its own set of atoms, or when I select something in the shared space does it snarf the selection away from private applications on other workstations? 4) Floor Control? What policies are available and how are they enforced? 5) Does it support truly multi-user applications? Are you using your protocol extension to support applications that present different views to different servers? 6) Does it allow new users to be brought in to existing "sharings" of windows? Can people leave and go as the please in a session? Can I keep a "conference" going while no-one is using the software? thanks for your help, ian -- "Daddy what's regret?" "Well son, all I can say is its always better to regret something you have done, than to regret something you haven't done. And, if you see you mother this afternoon..." --Gibby
garfinkel@hpfcso.FC.HP.COM (Dan Garfinkel) (06/08/91)
> Hm. I wonder how you system addresses a couple of my issues with > window sharing in X: > 1) How does it handle heterogenous visual classes? Can I run a shared > session on monochrome and color workstation simultaneously? > If so, what visual class does the shared window system present to > clients? Yes, you can share from mono to color and visa versa. SharedX takes care of translating to protocol so you can share to a display of a different visual type. SharedX will use whatever visual class the destination servers support. > 2) How does it handle window management contention? If it shares > "windows" and not "workstations" how do you avoid local copies of > the applications having dissimilar sizes? If you try to enforce the > same sizes on all copies, how do you avoid race conditions and > potential "oscillations" that cant be stopped? The only window attribute that matters to the application is size. In this case, we report the "Senders" window size to the application. If "Receivers" change their window size, information is either clipped or there is blank space in the window. If the sender changes size, that size to propagated to the receiver's windows. > 3) What about cut and paste? Does it have its own set of atoms, or > when I select something in the shared space does it snarf the selection > away from private applications on other workstations? Selections turned out to one of the hardest areas to support with SharedX by it's asynchronous nature. We didn't solve this one for our first release. When the receiver does an action which cause the selection to occur, the selection takes place on the sender's server. > 4) Floor Control? What policies are available and how are they > enforced? Each receiver of the window can either have input allowed or input disallowed. Any user with input allowed can input to the shared application. We do some amount of dynamic input locking to try to minimize intermixed keystrokes. > 5) Does it support truly multi-user applications? Are you using your > protocol extension to support applications that present different > views to different servers? No. This is not a design goal of SharedX and is not what SharedX is good at. > 6) Does it allow new users to be brought in to existing "sharings" > of windows? Can people leave and go as the please in a session? Can > I keep a "conference" going while no-one is using the software? Yes users can be added and removed at any time, under the control of the "Sender" of the window. There is really no notion of a "conference" in the user interface we provide with SharedX. -Dan
mouse@lightning.mcrcim.mcgill.EDU (der Mouse) (06/17/91)
[stuff about SharedX] >> 1) How does it handle heterogenous visual classes? > Yes, you can share from mono to color and visa versa. SharedX takes > care of translating to protocol so you can share to a display of a > different visual type. SharedX will use whatever visual class the > destination servers support. >> 6) Does it allow new users to be brought in to existing "sharings" >> of windows? Can people leave and go as the please in a session? > Yes users can be added and removed at any time, under the control of > the "Sender" of the window. Ummm. So, it always presents a one-bit StaticGray visual to its clients? This seems to run counter to your response to question 1, but since the protocol makes no provision for visuals suddenly disappearing out from under existing connections, it seems to be the only way to permit a typical one-bit workstation to join an existing session.... >> 2) How does it handle window management contention? > The only window attribute that matters to the application is size. You have a somewhat restricted notion of applications! How do you deal with windows whose bit-gravity is set to Static being moved on some but not all of the servers, or being moved by different amounts? der Mouse old: mcgill-vision!mouse new: mouse@larry.mcrcim.mcgill.edu
garfinkel@hpfcso.FC.HP.COM (Dan Garfinkel) (06/21/91)
> Ummm. So, it always presents a one-bit StaticGray visual to its > clients? This seems to run counter to your response to question 1, but > since the protocol makes no provision for visuals suddenly disappearing > out from under existing connections, it seems to be the only way to > permit a typical one-bit workstation to join an existing session.... No. The application still renders to the visual(s) on the senders system and SharedX takes care of translating the protocol to whatever visual is available on the receiver's system. So if the application puts an image to a 4 bit pseudo-color device and that window is being shared to a 24 bit true color device, SharedX will convert the image (including all the pixel values in the image) to render properly on the destination server(s). > >> 2) How does it handle window management contention? > > The only window attribute that matters to the application is size. > > You have a somewhat restricted notion of applications! How do you deal > with windows whose bit-gravity is set to Static being moved on some but > not all of the servers, or being moved by different amounts? SharedX does not do a perfect job at sharing all applications. This is just one example. To does, however, do a very good job at sharing most applications. -Dan