Arrays in structs are incorrecly GCed about lgi HOT 3 CLOSED

Confirmed, I can see the problem, thanks for the report. Generally, bindings are not good at handling complex typed struct field definitions liek arrays, because fields do not have transfer information attached in GI, and this is root of this problem. Typically, wrapped C interface provides construction methods for boxed structs which also take initialization values as arguments - something likeg_dbus_interface_info_create (const gchar *name, GDBusMethodInfo *methods, ...) but unfortunately GDBus introspection provides nothing like that.

I'm working on some solution here, I was almost there, but hunting final leak proved that I'm not on the right track. I'll continue some other day, when time permits. If it will work, something like following code could be used:

local node = Gio.DBusNodeInfo {
   path = '/some/path',
   interfaces = {
      Gio.DBusInterfaceInfo {
     name = 'SomeInterace',
     methods = {
        Gio.DBusMethodInfo {
           name = 'SomeMethod',
           in_args = {
          Gio.DBusArgInfo {
             name = 'args',
             signature = 's',
          },
          Gio.DBusArgInfo {
             name = 'argi',
             signature = 'i',
          },
           },
        },
     },
     properties = {
        Gio.DBusPropertyInfo {
           name = 'someProperty',
           signature = 's',
           flags = { 'READABLE', 'WRITABLE' },
        },
     },
      },
   },
}

This is quite nice Lua-style, but even more verbose than XML, so quite unsuitable to write manually. Maybe some IDL parser would be handy (probably task for lpeg? :-)

BTW, did you try to use Gio.DBusNodeInfo.new_for_xml()? I guess that this one should work fine as is.

from lgi.

Thank you for this detailed feedback :)

Actually, the PoC that I am working is based on function decorators, and some other metadata directly added to code in order to expose an object on DBus, so the Gio.DBusNodeInfo approach is definitely the way to go, as its verbosity is hidden anyway.

As you suggested; I tried to replace it by the Gio.DBusNodeInfo.new_for_xml() method and so far it seems to work: no more segfault on GC, and Valgrind does not complain anymore. So I will keep it like this for now.

from lgi.

I have pushed support for DBus*Info structures. Sample above should work nicely, and I also added Gio.DBusNodeInfo.xml attribute for easy XML generation.

One thing which is still 'broken' is reassigning of already assigned fields with new values (e.g. setting methods attribute when one is already set). This will result in memory leaks (old values are not freed), but this is generic GI field support limitation, so I tend to not fix this one, as it might get quite involved and complex, and I do not see much gain in it.

Please let me know if you find anything missing in DBus*Info support (or anywhere else :-).

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