The SessionManager service provides an interface to the session manager
of the desktop. A session manager keeps track of applications that are
running when the desktop shuts down and starts them again in the same
state they were left when the desktop starts up the next time. To be able
to do this the session manager needs cooperation from applications;
applications have to provide sufficient information to be started again as
well as restore the state they were left in. The normal flow of operation
looks like this:
The user starts the desktop shutdown.
The session manager informs all its connected applications
about the pending shutdown.
Each application saves its current state; while doing this it may
The application may request to interact with the user (e.g. to ask
where to save documents). This request is necessary because at any one
time only one application can iteract with the user. The session manager
coordinates these requests and grants every application in need of user
interaction a timeslot in which it may interact with the user
try to cancel the whole shutdown; the session manager may or may
not honor that request.
After saving is done the session manager signals all applications
to exit.
Applications answer the exit message by disconnecting from the
session manager.
After all applications have exited or a reasonable timeout the
session manager kills all remaining applications and finally lets the
desktop shut down.
XSessionManagerClient (of which there can only be one instance per
process) provides an application's interface to the session manager.
It keeps track of every listener inside the application and multiplexes
the session manager's signals as well as requests to the session manager.
XSessionManagerClient (of which there can only be one instance per
process) provides an application's interface to the session manager.
It keeps track of every listener inside the application and multiplexes
the session manager's signals as well as requests to the session manager.
