On 2013-11-30 00:38, Dan wrote:
Hi,
I can't find any documentation(*) stating positively whether
gobject.idle_add and timeout_add are safe to call from a non-main
thread (e.g. a gstreamer message callback). Specifically,
def work(*args):
# (1) gtk.gdk.threads_enter() ??
self.ui.change_some_label()
# (2) gtk.gdk.threads_leave() ??
# (3) gtk.gdk.threads_enter() ??
gobject.idle_add (work)
# (4) gtk.gdk.threads_leave() ??
Are (1)/(2) and/or (3)/(4) necessary? And for which pygtk versions
does this apply? I am targetting separately 2.12 (on an embedded
platform) and 2.24 (on the desktop).
(*) Except https://developer.gnome.org/gdk/unstable/gdk-Threads.html
which seems to be from 1999 and implies that __for gtk, not pygtk__
the g_idle_add requires both (1)/(2) and (3)/(4). I can't actually
find any recent GTK+ documentation that unambiguously resolves the
issue.
Both idle_add and timeout_add are thread safe, as are all GLib mainloop
functions AFAIK. It's the GTK and GDK functions you have to be careful
with. You don't need (3)/(4). You should still have (1)/(2), or "with
gtk.gdk.lock:" if your version of gtk is new enough. It may be easier to
create your own wrappers around idle_add and timeout_add like this:
def _callback_wrapper(func, *args, **kw):
gtk.gdk.threads_enter()
try:
return func(*args, **kw)
finally:
gtk.gdk.threads_leave()
def idle_add_lock(func, *args, **kw):
return gobject.idle_add(_callback_wrapper, func, *args, **kw)
def timeout_add_lock(milliseconds, func, *args, **kw):
return gobject.timeout_add(milliseconds,
_callback_wrapper, func, *args, **kw)
--
Tim Evans
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