server: add wl_global_set_user_data

When implementing a workaround for [1], one needs to accept a global to be
bound even though it has become stale.

Often, a global's user data is free'd when the global needs to be destroyed.
Being able to set the global's user data (e.g. to NULL) can help preventing a
use-after-free.

(The alternative is to make the compositor responsible for keeping track of
stale user data objects via e.g. refcounting.)

[1]: https://gitlab.freedesktop.org/wayland/wayland/issues/10

Signed-off-by: Simon Ser <contact@emersion.fr>
This commit is contained in:
Simon Ser 2019-07-22 19:41:22 +03:00 committed by Pekka Paalanen
parent 766edf0243
commit d5055ad913
2 changed files with 16 additions and 0 deletions

View file

@ -279,6 +279,9 @@ wl_global_get_interface(const struct wl_global *global);
void *
wl_global_get_user_data(const struct wl_global *global);
void
wl_global_set_user_data(struct wl_global *global, void *data);
struct wl_client *
wl_client_create(struct wl_display *display, int fd);

View file

@ -1245,6 +1245,19 @@ wl_global_get_user_data(const struct wl_global *global)
return global->data;
}
/** Set the global's user data
*
* \param global The global object
* \param data The user data pointer
*
* \since 1.17.90
*/
WL_EXPORT void
wl_global_set_user_data(struct wl_global *global, void *data)
{
global->data = data;
}
/** Get the current serial number
*
* \param display The display object