wayland/tests/signal-test.c
Simon Ser 962aefda42 server: introduce wl_signal_emit_mutable
wl_signal_emit doesn't handle well situations where a listener removes
another listener. This can happen in practice: wlroots and Weston [1]
both have private helpers to workaround this defect.

wl_signal_emit can't be fixed without breaking the API. Instead,
introduce a new function. Callers need to make sure to always remove
listeners when they are free'd.

[1]: https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/457

Signed-off-by: Simon Ser <contact@emersion.fr>
Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
2022-03-28 19:06:16 +00:00

159 lines
4.5 KiB
C

/*
* Copyright © 2013 Marek Chalupa
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <assert.h>
#include "wayland-server.h"
#include "test-runner.h"
static void
signal_notify(struct wl_listener *listener, void *data)
{
/* only increase counter*/
++(*((int *) data));
}
TEST(signal_init)
{
struct wl_signal signal;
wl_signal_init(&signal);
/* Test if listeners' list is initialized */
assert(&signal.listener_list == signal.listener_list.next
&& "Maybe wl_signal implementation changed?");
assert(signal.listener_list.next == signal.listener_list.prev
&& "Maybe wl_signal implementation changed?");
}
TEST(signal_add_get)
{
struct wl_signal signal;
/* we just need different values of notify */
struct wl_listener l1 = {.notify = (wl_notify_func_t) 0x1};
struct wl_listener l2 = {.notify = (wl_notify_func_t) 0x2};
struct wl_listener l3 = {.notify = (wl_notify_func_t) 0x3};
/* one real, why not */
struct wl_listener l4 = {.notify = signal_notify};
wl_signal_init(&signal);
wl_signal_add(&signal, &l1);
wl_signal_add(&signal, &l2);
wl_signal_add(&signal, &l3);
wl_signal_add(&signal, &l4);
assert(wl_signal_get(&signal, signal_notify) == &l4);
assert(wl_signal_get(&signal, (wl_notify_func_t) 0x3) == &l3);
assert(wl_signal_get(&signal, (wl_notify_func_t) 0x2) == &l2);
assert(wl_signal_get(&signal, (wl_notify_func_t) 0x1) == &l1);
/* get should not be destructive */
assert(wl_signal_get(&signal, signal_notify) == &l4);
assert(wl_signal_get(&signal, (wl_notify_func_t) 0x3) == &l3);
assert(wl_signal_get(&signal, (wl_notify_func_t) 0x2) == &l2);
assert(wl_signal_get(&signal, (wl_notify_func_t) 0x1) == &l1);
}
TEST(signal_emit_to_one_listener)
{
int count = 0;
int counter;
struct wl_signal signal;
struct wl_listener l1 = {.notify = signal_notify};
wl_signal_init(&signal);
wl_signal_add(&signal, &l1);
for (counter = 0; counter < 100; counter++)
wl_signal_emit(&signal, &count);
assert(counter == count);
}
TEST(signal_emit_to_more_listeners)
{
int count = 0;
int counter;
struct wl_signal signal;
struct wl_listener l1 = {.notify = signal_notify};
struct wl_listener l2 = {.notify = signal_notify};
struct wl_listener l3 = {.notify = signal_notify};
wl_signal_init(&signal);
wl_signal_add(&signal, &l1);
wl_signal_add(&signal, &l2);
wl_signal_add(&signal, &l3);
for (counter = 0; counter < 100; counter++)
wl_signal_emit(&signal, &count);
assert(3 * counter == count);
}
struct signal_emit_mutable_data {
int count;
struct wl_listener *remove_listener;
};
static void
signal_notify_mutable(struct wl_listener *listener, void *data)
{
struct signal_emit_mutable_data *test_data = data;
test_data->count++;
}
static void
signal_notify_and_remove_mutable(struct wl_listener *listener, void *data)
{
struct signal_emit_mutable_data *test_data = data;
signal_notify_mutable(listener, test_data);
wl_list_remove(&test_data->remove_listener->link);
}
TEST(signal_emit_mutable)
{
struct signal_emit_mutable_data data = {0};
/* l2 will remove l3 before l3 is notified */
struct wl_signal signal;
struct wl_listener l1 = {.notify = signal_notify_mutable};
struct wl_listener l2 = {.notify = signal_notify_and_remove_mutable};
struct wl_listener l3 = {.notify = signal_notify_mutable};
wl_signal_init(&signal);
wl_signal_add(&signal, &l1);
wl_signal_add(&signal, &l2);
wl_signal_add(&signal, &l3);
data.remove_listener = &l3;
wl_signal_emit_mutable(&signal, &data);
assert(data.count == 2);
}