[libgnome-volume-control/feature/gobject-cleanups: 2/8] channel-map: Don't specify default c_marshaller

[Niels De Graef <nielsdg src gnome org>]

commit 37a7dfcd5094c46abd09528adcb5d5c7040e2b61
Author: Niels De Graef <nielsdegraef gmail com>
Date:   Sun May 29 13:47:01 2022 +0200

    channel-map: Don't specify default c_marshaller
    
    Apart from being less code, this actually gives us a tiny performance
    improvement. Up until a few years ago, if you pass `NULL` as the
    marshaller for a signal, GLib would fall back to
    `g_cclosure_marshal_generic` which uses libffi to pack/unpack its
    arguments. One could avoid this by specifying a more specific
    marshaller which would then be used to immediately pack and unpack into
    GValues with the correct type.
    
    Lately however, as a way of optimizing signal emission (which can be
    quite expensive), GLib added a possibility to set a `va_marshaller`,
    which skips the unnecessary GValue packing and unpacking and just uses a
    valist variant.
    
    Since the performance difference is big enough, if the marshaller
    argument is NULL, `g_signal_new()` will now check for the simple
    marshallers (return type NONE and a single argument) and set both the
    generic and the valist marshaller. In other words, less code for us with
    behind-the-scenes optimizations.
    
    In case you also want va_marshallers for more complex signals, you can
    use `g_signal_set_va_marshaller()`.

 gvc-channel-map.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/gvc-channel-map.c b/gvc-channel-map.c
index bf4d737..688a451 100644
--- a/gvc-channel-map.c
+++ b/gvc-channel-map.c
@@ -166,8 +166,7 @@ gvc_channel_map_class_init (GvcChannelMapClass *klass)
                               G_TYPE_FROM_CLASS (klass),
                               G_SIGNAL_RUN_LAST,
                               G_STRUCT_OFFSET (GvcChannelMapClass, volume_changed),
-                              NULL, NULL,
-                              g_cclosure_marshal_VOID__BOOLEAN,
+                              NULL, NULL, NULL,
                               G_TYPE_NONE, 1, G_TYPE_BOOLEAN);
 }