Hi, thanks for the hints, however, some more questions below.. Donny Viszneki wrote: > I'm a bit of a newb to this, so others should feel free to correct me. > > On 10/2/07, Christian Buennig <masala@xxxxxx> wrote: >> Hi, >> >> I have a general question about the concepts of GLib main loops. >> >> I've read the GLib reference several times but still I don't get how >> main loops internally work. To be precisely, the following questions occur: >> >> * Do main loops exist per process or per thread? >> If I start a main loop in one thread (A) and add an IO watch in >> another thread (B), does this watch get added to the main loop of the >> thread A or B ? > > Technically per thread, but also per process. The purpose of the main > loop is so that events can be pushed into a queue and processed > sequentially as opposed to responding to asynchronous events in an > interrupted stack frame. The result is simpler coding because you > don't need to worry as much about thread-safety. > >> * If there is only one main loop (regardless of per thread or per >> process), why the function g_main_loop_new()? > > You can use multiple threads each having their own GMainLoop. But many > applications don't need it. Obviously however, such applications can > become unresponsive if they come under heavy load. Ok. This is not a suggestion to change the GLib API, but to make sure I understood it right: Semantically a function name like: g_main_loop_get_ref(..) would better describe what this function does? I think so because I guess calling g_main_loop_new(..) within the same thread multiple times technically always gives a reference to the same main loop .. > >> * What's the purpose of the parameter 'is_running' in >> g_main_loop_new() ? When should I set it to TRUE and when to FALSE? > > You should not set these values yourself. They are set by glib API > calls which enter and exit one or multiple iterations of the loop. Well, the API forces me to set something for this parameter when I create a new main loop with: g_main_loop_new(GMainContext *context, gboolean is_running) As I understand the GLib reference, it does not matter how to set 'is_running' if I call g_main_loop_run(..) later. However, I just wonder why there is this parameter if it does not make sense for API users. > >> Sorry for this basic questions .. if I am not the only one dealing with >> these questions, maybe the GLib reference could get extended with more >> details on main loops. > > Yeah, "glib-The-Main-Event-Loop.html" is a strikingly opaque piece of > documentation. > >> Cheers .. and thanks for some advise, >> >> Christian >> _______________________________________________ gtk-list mailing list gtk-list@xxxxxxxxx http://mail.gnome.org/mailman/listinfo/gtk-list
