wlroots/util/signal.c

35 lines
1.1 KiB
C

#include "util/signal.h"
static void handle_noop(struct wl_listener *listener, void *data) {
// Do nothing
}
void wlr_signal_emit_safe(struct wl_signal *signal, void *data) {
struct wl_listener cursor;
struct wl_listener end;
/* Add two special markers: one cursor and one end marker. This way, we know
* that we've already called listeners on the left of the cursor and that we
* don't want to call listeners on the right of the end marker. The 'it'
* function can remove any element it wants from the list without troubles.
* wl_list_for_each_safe tries to be safe but it fails: it works fine
* if the current item is removed, but not if the next one is. */
wl_list_insert(&signal->listener_list, &cursor.link);
cursor.notify = handle_noop;
wl_list_insert(signal->listener_list.prev, &end.link);
end.notify = handle_noop;
while (cursor.link.next != &end.link) {
struct wl_list *pos = cursor.link.next;
struct wl_listener *l = wl_container_of(pos, l, link);
wl_list_remove(&cursor.link);
wl_list_insert(pos, &cursor.link);
l->notify(l, data);
}
wl_list_remove(&cursor.link);
wl_list_remove(&end.link);
}