[PATCH 1/1] tests: Add free-without-remove test

[Derek Foreman]

On 2018-02-23 07:44 AM, Markus Ongyerth wrote:
> On 2018/2月/23 07:31, Derek Foreman wrote:
>> On 2018-02-23 03:52 AM, wl at ongy.net wrote:
>>> From: Markus Ongyerth <wl at ongy.net>
>>>
>>> This is related to the discussion earlier on the mailing list and
>>> demonstrates a problem with current wl_priv_signal_emit and wl_listener
>>> that free themselves, but do not remove from the list.
>>>
>>> This testcase asserts that the wl_list inside wl_listener is not written
>>> to anymore after it got emitted.
>>> ---
>>>    Makefile.am                 |  3 +++
>>>    tests/free-without-remove.c | 63 +++++++++++++++++++++++++++++++++++++++++++++
>>>    2 files changed, 66 insertions(+)
>>>    create mode 100644 tests/free-without-remove.c
>>>
>>> diff --git a/Makefile.am b/Makefile.am
>>> index 322d6b8..c51f328 100644
>>> --- a/Makefile.am
>>> +++ b/Makefile.am
>>> @@ -158,6 +158,7 @@ pkgconfig_DATA += egl/wayland-egl-backend.pc
>>>    built_test_programs =				\
>>>    	array-test				\
>>> +	free-without-remove-test		\
>>>    	client-test				\
>>>    	display-test				\
>>>    	connection-test				\
>>> @@ -223,6 +224,8 @@ libtest_runner_la_LIBADD =			\
>>>    array_test_SOURCES = tests/array-test.c
>>>    array_test_LDADD = libtest-runner.la
>>> +free_without_remove_test_SOURCES = tests/free-without-remove.c
>>> +free_without_remove_test_LDADD = libtest-runner.la
>>>    client_test_SOURCES = tests/client-test.c
>>>    client_test_LDADD = libtest-runner.la
>>>    display_test_SOURCES = tests/display-test.c
>>> diff --git a/tests/free-without-remove.c b/tests/free-without-remove.c
>>> new file mode 100644
>>> index 0000000..ff468d7
>>> --- /dev/null
>>> +++ b/tests/free-without-remove.c
>>> @@ -0,0 +1,63 @@
>>> +/*
>>> + * Copyright © 2018 Markus Ongyerth
>>> + *
>>> + * 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 <stdio.h>
>>> +#include <stdlib.h>
>>> +#include <stdarg.h>
>>> +#include <string.h>
>>> +#include <assert.h>
>>> +#include <sys/socket.h>
>>> +#include <unistd.h>
>>> +#include <errno.h>
>>> +#include <sys/types.h>
>>> +#include <sys/stat.h>
>>> +
>>> +#include "wayland-private.h"
>>> +#include "wayland-server.h"
>>> +#include "test-runner.h"
>>> +
>>> +static void
>>> +display_destroy_notify(struct wl_listener *l, void *data)
>>> +{
>>> +	l->link.prev = l->link.next = NULL;
>>> +}
>>> +
>>> +TEST(free_without_remove)
>>> +{
>>> +	struct wl_display *display;
>>> +	struct wl_listener a, b;
>>> +
>>> +	display = wl_display_create();
>>> +	a.notify = display_destroy_notify;
>>> +	b.notify = display_destroy_notify;
>>> +
>>> +	wl_display_add_destroy_listener(display, &a);
>>> +	wl_display_add_destroy_listener(display, &b);
>>> +
>>> +	wl_display_destroy(display);
>>> +
>>> +	assert(a.link.next == a.link.prev && a.link.next == NULL);
>>> +	assert(b.link.next == b.link.prev && b.link.next == NULL);
>>
>> I feel this would be slightly more clear if it tested
>> a.link.next == NULL && a.link.prev == NULL
> Possibly.
>>
>> As my previously submit test did... is this significantly more rigorous than
>> my test here: https://patchwork.freedesktop.org/patch/206013/  ?
> Did you try to run this one? It *fails* on the current version of libwayland,
> because wl_priv_signal_emit will write into one of the wl_listeners after it
> got emitted.
> 
> This only happens where there's more than one listener in the signal list,
> which is the reason your test doesn't catch it.

More rigorous indeed - but we can't land it without fixing the bug first. :)

Also, I'm not sure it warrants a whole new file when it could just piggy 
back an existing test...  I guess now that I think about it, signal-test 
seems most appropriate?

Thanks,
Derek

>>
>> Thanks,
>> Derek
>>
>>> +}
>>>
>>
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