Locking graphics system - GUI/octave synchronization

[Michael Goffioul]

Hi,

I know this has been discussed before, but would anyone see a major problem
or showstopper in adding a mutex-based locking system that would allow
to globally lock the graphics system? (through the use of specific methods
in gh_manager, like lock() and unlock()).

I'm currently investigating the implementation of an event-queue in octave,
which would allow a backend to post a callback from any thread, such that
the callback is executed in the octave thread. During this posting, I need
to check various things, like whether another callback is executing, whether
it's interruptible, whether busyaction tells me to queue or discard the
event... During these operations, I don't want the graphics system to change
state, so a global locking scheme would really help.

If anybody objects, then I'll integrate this in the graphics mq. This will be
based on the proposal I made a few months ago and on the more recent
proposal from Maciek.

Bye,
Michael.