Re: A doube about gvariant

[Federico Mena Quintero <federico gnome org>]

On Tue, 2013-04-23 at 17:21 +0800, jiangpengfei wrote:

>          I have a doubt about the use of gvariant.
>
>          In the source file:
> glib-2.34.3/gio/tests/gdbus-test-codegen.c:860,
> foo_igen_bar_call_test_primitive_types_sync uses a address of
> ret_val_bytestring, which is a local variable which type is gchar *.
> After function returns, ret_val_bytestring will be pointed to a memory
> section, and I know this section is got from a inner gvariant
> variable. But does someone can tell me when and how should I release
> this memory?

Just call g_free() on it.

As far as I can tell, this memory is allocated in
g_variant_dup_string(), as called by g_variant_valist_get_nnp(), called
in turn by g_variant_valist_get_leaf().

Normally the lifetime of values inside a GVariant is tied to the variant
itself.  But the generated functions from gdbus pull out the values with
g_variant_get() - that duplicates the values for your own use.  You can
see those calls to g_variant_get() in gdbus-test-codegen-generated.c
after you build glib.

  Federico