Re: Threading Problem

[Chris Vine <chris cvine freeserve co uk>]

On Wednesday 27 September 2006 20:44, Chris Vine wrote:

> Both Glib::Dispatcher and Glib::SignalIdle should work similarly.
> Glib::Dispatcher uses a pipe under the covers, as does Glib::SignalIdle
> when used with Unix-like systems, although with different priorities in the
> main program loop, which will probably not make any difference in practice.
>  I do not know if Glib::Dispatcher works with windows if you are interested
> in portablility, although Glib::SignalIdle does.  The important thing with
> Glib::SignalIdle is to remember to have the handler return false. 
> Returning true can turn your main loop into a busy wait.

And I should add that this leads to the main difference in practice - with 
Glib::Dispatcher you connect the slot once and can execute it any time by 
calling emit() on the dispatcher object (it operates as a thread safe 
signal).  With Glib::SignalIdle it fires once (the handler must return false) 
so you have to reconnect the slot everytime you want it to execute.

This also means in practice that with Glib::Dispatcher it naturally leads to 
passing arguments in queues or similar mechanisms, rather than trying to bind 
to the slot.

Chris