new funtional: shared memory -> sockets?

Question

new funtional: shared memory -> sockets?

gogonaft opened this issue 8 years ago · 12 comments

Hi, I wonder could X shared memory code be re-written so that socket transmission is used instead?

I'm trying to get remoteink working over SSH and it does not work with shm-* functions.
It works nicely if I run X11 on host itself, though.

UPD: looks like the problem is not with shared memory but with remoteinkd server itself. No additional error is thrown if shm* execs were disabled in code. Server running showing black screen on client.

Answer 1 · 2016-12-31T22:41:31.000Z

Hi @gogonaft,

I think I've fixed this issue in a2bc570, so you can try a new server version from master.

Actually, receiving of a screenshot via sockets has already been implemented, but detection of the fact that shared memory is unavailable didn't work properly in this case.

Answer 2 · 2017-01-02T04:02:53.000Z

Thank for quick reaction, @borzunov. But it looks like it does the same thing to me: saying error about shared mem and exits. What is the best way to troubleshoot it?
Jan 1 19:59:09 raspberrypi remoteinkd: Failed to attach shared memory Jan 1 19:59:09 raspberrypi remoteinkd: Unknown key "KP_Delete" in shortcut "Ctrl+Alt+KP_Delete"

Workaround is to use x11vnc.

Answer 3 · 2017-01-02T12:19:34.000Z

Unfortunately, it isn't clear from the logs, but Failed to attach shared memory message is just a non-critical notice, and Unknown key "KP_Delete" in shortcut "Ctrl+Alt+KP_Delete" is an actual reason of failure.

I suggest trying to comment out a line with a mention of KP_Delete key in /etc/remoteinkd/config.ini. If this helps, you can leave the shortcut disabled or rebind the action to another key.

Answer 4 · 2017-01-02T18:55:41.000Z

Did not think shortcuts would cause this. I've commented them and remoteinkd started.
But, it's showing black screen only if I try through "ssh -X"(tried with xclock, lxterminal, lxsession).

Answer 5 · 2017-01-02T19:09:16.000Z

The following configuration works for me:

I have two machines, one runs my desktop environment (machine A, Ubuntu), and another will run remoteinkd (machine B, Fedora).
I can connect from machine A to machine B through ssh -X and start remoteinkd there using:
```
 sudo -E remoteinkd start
```
Then I can connect from the reader to machine B and see the desktop of machine A.

Is this what you are trying to do, or how does your configuration differ?

Answer 6 · 2017-01-02T19:24:35.000Z

Using it in exactly same way, only that A=MacOS. I don't have problem seeing X apps opened via this ssh-session on A, but only black screen is on Reader.
Jan 2 11:20:11 raspberrypi remoteinkd: Monitor resolution: 1680x1027 Jan 2 11:20:11 raspberrypi remoteinkd: Server listens on 0.0.0.0:9312 Jan 2 11:20:20 raspberrypi remoteinkd: Accepted client connection from 192.168.X.X Jan 2 11:20:20 raspberrypi remoteinkd: Reader resolution: 800x600

Answer 7 · 2017-01-02T20:36:54.000Z

Try to run an utility like scrot inside the SSH connection to B. It will save a screenshot of the desktop to a file in the current directory in B. Does this screenshot contain anything? Will it contain anything if you run xclock simultaneously in the same SSH connection?

Answer 8 · 2017-01-03T06:28:19.000Z

scrot always gives blank screen inside SSH session to B. Looks like problem somewhere on my side.

Answer 9 · 2017-01-03T17:11:45.000Z

As far as I understood, Mac OS X native apps don't use X11, and there's no opportunity to make a screenshot of these apps via X11. That's a reason why scrot and remoteinkd (which uses only X11 to capture the screen) don't work in this case.

Answer 10 · 2017-01-04T02:00:07.000Z

MacOS has port of X11 and it is used for X apps. Somehow scrot not capturing that screen though.

Answer 11 · 2017-01-04T02:07:13.000Z

Yeah, but I suppose this port is not able to capture the screen with non-X11 apps (these apps may use other screen buffers, which are inaccessible from X11).

Answer 12 · 2017-01-27T23:29:52.000Z

Since it doesn't look that the problem is in remoteink app, I will close this for now. Don't hesitate to open another issue if you find other problems related to remoteink.