Re: [SyncEvolution] GDBus C++ add_filter + fork/exec dbus-server

W dniu 15 marca 2012 10:58 użytkownik Krzesimir Nowak <qdlacz(a)gmail.com&gt; napisał: > 2012/3/15 Patrick Ohly <patrick.ohly(a)intel.com&gt;: >> On Thu, 2012-03-15 at 10:21 +0100, Krzesimir Nowak wrote: >>> W dniu 14 marca 2012 15:30 użytkownik Patrick Ohly >>> <patrick.ohly(a)intel.com&gt; napisał: >>> > Hello Krzesimir! >>> > >>> > You added the add/remove_filter() methods to DBusConnectionPtr, with the >>> > comment "those additions will be needed for ForkExec ready message >>> > handling" in the commit message. >>> > >>> > The methods themselves are not documented. Can you explain a bit how >>> > this is meant to work? >>> >>> The history is that I needed to add a new signal to ForkExec, because >>> activation of DBus interface on child side was racing with using this >>> interface on parent side. >> >> Wouldn't it be easier to delay message processing on the child side >> until the child is set up, then enable the message processing? >> >> http://developer.gnome.org/gio/unstable/GDBusConnection.html#GDBusConnect... >> mentions G_DBUS_CONNECTION_FLAGS_DELAY_MESSAGE_PROCESSING and >> g_dbus_connection_start_message_processing() for this purpose. >> >> Then the parent can start making method calls right away. They simply >> will not be processed before the child is really ready to handle them. > > I have not noticed that before - I will check it. Nope, still racy. I tested that by running a loop with 100 iterations of TestDBusServerPresence and breaking it after first failure. It got me as far as 34 iterations. Usually first 15-20 iteration succeeded. Failures on 1 iteration weren't all that rare. I have created two quick-and-dirty branches with my two attempts to solve the problem with g_dbus_connection_start_message_processing(): 1. with running said function directly: https://meego.gitorious.org/~krnowak/meego-middleware/krnowaks-syncevolut... 2. with running said function in idle callback: https://meego.gitorious.org/~krnowak/meego-middleware/krnowaks-syncevolut...