[vlc-devel] [vlc-commits] modules: store object name in a variable
Rémi Denis-Courmont
remi at remlab.net
Tue Mar 5 11:04:02 CET 2019
Hi,
There is no such thing as absolute thread safety, except for trivial useless constructs.
Accessing object variables, flags and logger for an object whose nature and ownership is known may be safe, e.g. getting input or output objects from playlist.
Accessing an unknown object is not. As already noted, variables, logging and flags are not thread-safe in the general case. Besides, how do you get to that object in the first place? You cannot safely manifest a reference out of thin air.
Le 5 mars 2019 11:35:05 GMT+02:00, Thomas Guillem <thomas at gllm.fr> a écrit :
>
>On Tue, Mar 5, 2019, at 10:28, Rémi Denis-Courmont wrote:
>> I don't mean "you" as just your individuality as opposed to the
>group. I mean you as in the group including you, as opposed to the
>group excluding you (because you weren't there, or hypothetically
>because you'd left).
>>
>> And I have been disentangling VLC object and fixing threads for over
>a decade (quite often they are two sides of the same coin). I am not
>the least bit interested in giving up so close. But if the tech
>commitee out-votes me, I will stop caring.
>>
>> I wouldn't want to be using a thread sanitizer if this happens
>though. In fact, I don't think I would want to use VLC on an SMP system
>at all.
>
>Why ? VLC object variables are thread safe, no ? There is just a TOCTOU
>issue. I guess that's OK if it's used only for debugging.
>
>>
>> Le 5 mars 2019 11:12:52 GMT+02:00, Thomas Guillem <thomas at gllm.fr> a
>écrit :
>>> On Tue, Mar 5, 2019, at 10:02, Rémi Denis-Courmont wrote:
>>>> Yeah. And we never agreed to un-deprecate object names and allow
>them to be used by plugins back again. And I did even remind of the
>deprecation at the last workshop less than two weeks ago - not exactly
>a surprise.
>>>
>>> We didn't decided to break the QT module dialog. This feature is
>very very useful for user support, I don't think we can't ride of it.
>>>
>>> And yes, It happens to me a lot: I decide to a technical solution, I
>try to implement it and I encounter something I didn't planned.
>>>
>>> For me, module_t still need to be tied to vlc_object_t
>>>
>>>>
>>>> What you want is that all changes are agreed upon by you. That's
>not what we agreed.
>>>
>>> Not me, but us. If developers that are doing a lot more user support
>than me (Francois, Steve, Hugo and JB) agree to kill the QT module
>dialog, I won't be against the common decision.
>>>
>>>>
>>>> Le 5 mars 2019 10:48:21 GMT+02:00, Thomas Guillem <thomas at gllm.fr>
>a écrit :
>>>>> On Tue, Mar 5, 2019, at 09:43, Rémi Denis-Courmont wrote:
>>>>>> No. I am not accountable for bugs pushed by Antoine (object
>names), the other Rémi (Qt objects tree) and François (adding code
>using a feature that's already deprecated and of course without
>review).
>>>>>
>>>>> And that is why, we decided to always go to the mailing list when
>we add/remove new features or modify the VLC/LibVLC core API. It's
>useless to lament on what was done on the past or find a culprit for
>bad things that were done a *long* time ago.
>>>>>
>>>>>>
>>>>>> Unlike you, I have spent days trying to fix these things with
>variable success. And now, you are preventing me from fixing that for
>good.
>>>>>>
>>>>>> So if somebody's accountable, it's you.
>>>>>>
>>>>>> Le 5 mars 2019 10:17:34 GMT+02:00, Steve Lhomme
><robux4 at ycbcr.xyz> a écrit :
>>>>>>> On 3/5/2019 8:52 AM, Rémi Denis-Courmont wrote:
>>>>>>>> I am not going to hold your hand running git-log or git-blame.
>The
>>>>>>>> facts are there, you just don't care to look for them
>preferring to
>>>>>>>> band against me.
>>>>>>>
>>>>>>> You're accountable for the things you push on VLC just like the
>rest of
>>>>>>> us. If people disagree with a change you made without discussing
>you
>>>>>>> have to explain why, just like the rest of us. Saying it was
>already
>>>>>>> discussed 10 years ago (as a flamewar, so definitely not in the
>SVN
>>>>>>> logs) with other people is not a way to collaborate.
>>>>>>>
>>>>>>> >
>>>>>>>> And it's not exactly rocket science that introspection does
>not work
>>>>>>>> across threads - in general, not just in VLC.
>>>>>>>>
>>>>>>>> Le 5 mars 2019 09:03:43 GMT+02:00, Steve Lhomme
><robux4 at ycbcr.xyz> a
>>>>>>>> écrit :
>>>>>>>>
>>>>>>>> On 3/4/2019 9:51 PM, Rémi Denis-Courmont wrote:
>>>>>>>>
>>>>>>>> Decreeing that discussions older than 3 is irrelevant
>is
>>>>>>>> ridiculous.
>>>>>>>>
>>>>>>>>
>>>>>>>> Yes and no. Valid points many years ago are likely to be
>valid today.
>>>>>>>> But if we're not presented with them there is no way to
>know. The code
>>>>>>>> has changed a lot in the last few years and will continue
>to do so. Some
>>>>>>>> things that used to be true may not be anymore and vice
>versa. But we
>>>>>>>> need the facts, not "it was discussed 9 years ago, end of
>discussion". vlc-devel mailing list
>>>>>>>> To unsubscribe or modify your subscription options:
>>>>>>>> https://mailman.videolan.org/listinfo/vlc-devel
>>>>>>>>
>>>>>>>>
>>>>>>>> --
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>Veuillez
>>>>>>>> excuser ma brièveté. vlc-devel mailing list
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>>>>>>> vlc-devel mailing list
>>>>>>> To unsubscribe or modify your subscription options:
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>>>>>>
>>>>>> --
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>>>>>
>>>>
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