[vlc-devel] [PATCH] decoder: avoid vout requests spam
Rémi Denis-Courmont
remi at remlab.net
Sat Jul 1 19:38:02 CEST 2017
Le 1 juillet 2017 17:53:54 GMT+02:00, Thomas Guillem <thomas at gllm.fr> a écrit :
>
>
>
>On Sat, Jul 1, 2017, at 17:46, Rémi Denis-Courmont wrote:
>> Le 1 juillet 2017 17:44:30 GMT+02:00, Thomas Guillem <thomas at gllm.fr>
>> a écrit :>>
>>>
>>>
>>> On Sat, Jul 1, 2017, at 17:33, Rémi Denis-Courmont wrote:
>>>> Le 1 juillet 2017 16:54:42 GMT+02:00, Thomas Guillem
>>>> <thomas at gllm.fr> a écrit :>>>> ---
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> src/input/decoder.c | 20 ++++++++++++++++++++
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> 1 file changed, 20 insertions(+)
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> diff --git a/src/input/decoder.c b/src/input/decoder.c
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> index dac313737a..23e5a7356b 100644
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --- a/src/input/decoder.c
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> +++ b/src/input/decoder.c
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> @@ -54,6 +54,11 @@
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> #include "../video_output/vout_control.h"
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> +/* Number of vout request failures after we slow down vout
>>>>> requests */
>>>>>>>>>
>>>>>
>>>>>
>>>>> +#define VOUT_MAX_FAILURE 10
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> +/* Delay between each failing vout requests */
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> +#define VOUT_RETRY_DELAY 1000000UL
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> +
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> /*
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> * Possibles values set in p_owner->reload atomic
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> */
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> @@ -108,6 +113,8 @@ struct decoder_owner_sys_t
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> audio_output_t *p_aout;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> vout_thread_t *p_vout;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> + unsigned vout_nb_failures;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> + mtime_t vout_last_failure;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> /* -- Theses variables need locking on read *and* write -- */
>>>>>>>>>
>>>>>
>>>>>
>>>>> /* Preroll */
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> @@ -408,6 +415,13 @@ static int vout_update_format( decoder_t
>>>>> *p_dec )
>>>>>>>>>
>>>>>
>>>>>
>>>>> {
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> decoder_owner_sys_t *p_owner = p_dec->p_owner;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> + /* Avoid to spam vout requests if no vout is capable of
>>>>> handling the
>>>>>>>>>
>>>>>
>>>>>
>>>>> + * current format. We should still request vouts from time to
>>>>> time since a
>>>>>>>>>
>>>>>
>>>>>
>>>>> + * vout can become available in between. */
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> + if( p_owner->vout_nb_failures > VOUT_MAX_FAILURE
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> + && mdate() - p_owner->vout_last_failure < VOUT_RETRY_DELAY )
>>>>>>>>>
>>>>>
>>>>>
>>>>> + return -1;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> +
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> if( p_owner->p_vout == NULL
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> || p_dec->fmt_out.video.i_width !=
>p_owner->fmt.video.i_width
>>>>>>>>>
>>>>>
>>>>>
>>>>> || p_dec->fmt_out.video.i_height != p_owner-
>>>>> || >fmt.video.i_height
>>>>>>>>>
>>>>>
>>>>>
>>>>> @@ -530,8 +544,12 @@ static int vout_update_format( decoder_t
>>>>> *p_dec )
>>>>>>>>>
>>>>>
>>>>>
>>>>> if( p_vout == NULL )
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> {
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> msg_Err( p_dec, "failed to create video output" );
>>>>>>>>>
>>>>>
>>>>>
>>>>> + p_owner->vout_nb_failures++;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> + p_owner->vout_last_failure = mdate();
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> return -1;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> }
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> + p_owner->vout_nb_failures = 0;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> + p_owner->vout_last_failure = 0;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> }
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> if ( memcmp( &p_dec->fmt_out.video.mastering,
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> @@ -1662,6 +1680,8 @@ static decoder_t * CreateDecoder(
>>>>> vlc_object_t *p_parent,
>>>>>>>>>
>>>>>
>>>>>
>>>>> p_owner->p_resource = p_resource;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> p_owner->p_aout = NULL;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> p_owner->p_vout = NULL;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> + p_owner->vout_nb_failures = 0;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> + p_owner->vout_last_failure = 0;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> p_owner->p_spu_vout = NULL;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> p_owner->i_spu_channel = 0;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> p_owner->i_spu_order = 0;
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>> AFAICT, retrying does not make sense. Just fail immediately if the
>>>> format is the same as before. It cannot be assumed that the decoder
>>>> will actually keep retrying with the same format (even now, that is
>>>> not always true).>>
>>> Fail immediately ? I was in favor of that solution but someone
>(maybe
>>> you ?) told me that we should always retry because we can't know the
>>> reason of the failure. This could be because of low memory, a
>>> driver/display not available that can became available just after
>few
>>> seconds.>>
>>> Even with that in mind, I prefer to fail immediately than doing this
>>> delay hack.>>
>>>>
>>>> With that said, you can't expect this to really prevent spam. The
>>>> decoder could just as well iterate multiple failing formats again
>>>> and again. So I'd say this patch is kinda useless.>>> --
>>>> Rémi Denis-Courmont
>>>> Typed on an inconvenient virtual keyboard
>>>> _________________________________________________
>>>> vlc-devel mailing list
>>>> To unsubscribe or modify your subscription options:
>>>> https://mailman.videolan.org/listinfo/vlc-devel
>>>
>>
>> We cannot really assume anything at that level either way. This would
>> be second-guessing the decoder and the video outputs.>
>> You could rate limit the error message though.
>
>The main problem is the window creation/deletion glitch, not the
>error message.
>You can easily reproduce it with ./vlc --vout sdl for example. (keep in
>mind that this problem can happen without forcing any vout).
>> --
>> Rémi Denis-Courmont
>> Typed on an inconvenient virtual keyboard
>> _________________________________________________
>> vlc-devel mailing list
>> To unsubscribe or modify your subscription options:
>> https://mailman.videolan.org/listinfo/vlc-devel
There are no solutions to that problem that wot either break something else or require drastic changes to the windowing code.
So live with it for now.
--
Rémi Denis-Courmont
Typed on an inconvenient virtual keyboard
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