[Spice-devel] [PATCH spice-gtk] Make sure our foo_get_type functions are thread-safe

[Marc-André Lureau]

ack

----- Mensaje original -----
> While debugging:
> https://bugzilla.redhat.com/show_bug.cgi?id=866718
> 
> I found a thread-safeness issue with a couple of foo_get_type functions
> in polkit causing this crash.
> 
> After this I decided to check if spice-gtk has the same issue, and it does,
> since foo_get_type can be called from different threads, it is important to
> make them thread-safe.
> 
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> ---
>  gtk/Makefile.am          | 18 ++++++++++++------
>  gtk/spice-grabsequence.c |  5 ++++-
>  2 files changed, 16 insertions(+), 7 deletions(-)
> 
> diff --git a/gtk/Makefile.am b/gtk/Makefile.am
> index 17544fb..d31a396 100644
> --- a/gtk/Makefile.am
> +++ b/gtk/Makefile.am
> @@ -455,9 +455,12 @@ spice-glib-enums.c: spice-channel.h channel-inputs.h
> spice-session.h
>  			--vprod "  { @VALUENAME@, \"@VALUENAME@\", \"@valuenick@\" }," \
>  			--vtail "  { 0, NULL, NULL }\n};\n\n" \
>  			--vtail "GType\n at enum_name@_get_type (void)\n{\n" \
> -			--vtail "  static GType type = 0;\n\n" \
> -			--vtail "  if (!type)\n" \
> -			--vtail "    type = g_ at type@_register_static (\"@EnumName@\",
> _ at enum_name@_values);\n\n" \
> +			--vtail "  static GType type = 0;\n" \
> +			--vtail "  static volatile gsize type_volatile = 0;\n\n" \
> +			--vtail "  if (g_once_init_enter(&type_volatile)) {\n" \
> +			--vtail "    type = g_ at type@_register_static (\"@EnumName@\",
> _ at enum_name@_values);\n" \
> +			--vtail "    g_once_init_leave(&type_volatile, type);\n" \
> +			--vtail "  }\n\n" \
>  			--vtail "  return type;\n}\n\n" \
>  		$^ > $@
>  
> @@ -479,9 +482,12 @@ spice-widget-enums.c: spice-widget.h
>  			--vprod "  { @VALUENAME@, \"@VALUENAME@\", \"@valuenick@\" }," \
>  			--vtail "  { 0, NULL, NULL }\n};\n\n" \
>  			--vtail "GType\n at enum_name@_get_type (void)\n{\n" \
> -			--vtail "  static GType type = 0;\n\n" \
> -			--vtail "  if (!type)\n" \
> -			--vtail "    type = g_ at type@_register_static (\"@EnumName@\",
> _ at enum_name@_values);\n\n" \
> +			--vtail "  static GType type = 0;\n" \
> +			--vtail "  static volatile gsize type_volatile = 0;\n\n" \
> +			--vtail "  if (g_once_init_enter(&type_volatile)) {\n" \
> +			--vtail "    type = g_ at type@_register_static (\"@EnumName@\",
> _ at enum_name@_values);\n" \
> +			--vtail "    g_once_init_leave(&type_volatile, type);\n" \
> +			--vtail "  }\n\n" \
>  			--vtail "  return type;\n}\n\n" \
>  		$< > $@
>  
> diff --git a/gtk/spice-grabsequence.c b/gtk/spice-grabsequence.c
> index dab438c..5d6fa9f 100644
> --- a/gtk/spice-grabsequence.c
> +++ b/gtk/spice-grabsequence.c
> @@ -28,12 +28,15 @@
>  GType spice_grab_sequence_get_type(void)
>  {
>  	static GType grab_sequence_type = 0;
> +	static volatile gsize grab_sequence_type_volatile;
>  
> -	if (G_UNLIKELY(grab_sequence_type == 0)) {
> +	if (g_once_init_enter(&grab_sequence_type_volatile)) {
>  		grab_sequence_type = g_boxed_type_register_static
>  			("SpiceGrabSequence",
>  			 (GBoxedCopyFunc)spice_grab_sequence_copy,
>  			 (GBoxedFreeFunc)spice_grab_sequence_free);
> +		g_once_init_leave(&grab_sequence_type_volatile,
> +				  grab_sequence_type);
>  	}
>  
>  	return grab_sequence_type;
> --
> 1.8.2.1
> 
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