Suggestion: Crash watch utility

[Stefan Stuhr]

Hi,

This e-mail contains a suggestion. If you don't want to (or doesn't have
time to) implement it, I'm fine with that, but I won't know if I doesn't
try to suggest it.

*** The problem ***
Applications crashes. It happens. Sometimes, on some installations, it
happens with xfce4-panel, or xfdesktop, or some other core application
which is important for users.
It shouldn't happen. When it does, it's a bug, and it should be fixed.
But sometimes, it does.

Then novices often tries to log out and in again, or restart their
computer, with the expectation that everything will be all right again.
And then, in the process, they often happens to save their session,
without said core application. As such, when they log in to Xfce again,
said core application won't start with their session.
Then they often have to search or ask for help, e.g. on the Xfce mailing
list.

*** Example case ***
http://foo-projects.org/pipermail/xfce/2006-May/017281.html

*** Suggested solution ***
When one of the core applications considered an integrated part of the
desktop (xfce4-panel, xfdesktop, xfwm4, xfce-mcs-manager) crashes, a
message dialog could pop up with some text explaining that said
application appears to have crashed (and maybe even encourage to submit
a bug report, if it is indeed the case - eventually add a link button
linking to bugzilla.xfce.org), with two buttons: "Close" and "Start
again". "Close" should close the dialog; "Start again" should try to
start the application again.

*** Suggested implementation ***
A lightweight utility, named xfce4-crashwatch, could be written. Then,
xfce4-session could start xfce4-panel, xfdesktop, xfwm4 and
xfce-mcs-manager with commands like this:
    xfce4-crashwatch xfce4-panel --sm-client-id [SM_CLIENT_ID]
--display :0.0
where [SM_CLIENT_ID] is the sm client id.

A list, containing said core applications, could be implemented in
xfce4-session, and be used to deside when to use xfce4-crashwatch, in
order to ensure that it will always be used for said core applications.

xfce4-crashwatch could run it's first argument as a child process, with
the second and following arguments of xfce4-crashwatch as arguments for
the child process, and wait for the child process to exit.
Then it could use the return code of the child process to decide whether
it appeared to have crashed, and in that case, run another utility (in
order to keep xfce4-crashwatch as lightweight as possible) which showed
the message dialog described in the "Suggested solution" section above.
Then, depending on the return code of said another utility, it could
either start over again (i.e. run it's first argument as a child
process, etc.) or exit.

Thanks,
Stefan