On Thu, Jun 06, 2024 at 04:24:11PM +0200, Michael Niedermayer wrote: > On Thu, Jun 06, 2024 at 09:29:24AM +0100, Andrew Sayers wrote: > > On Thu, Jun 06, 2024 at 01:17:48AM +0200, Michael Niedermayer wrote: > > [...] > > > AVOption simply provides light weight access to the struct fields. > > > Calling AVOption non re-entrant in modifying a field you arent even > > > allowed > > > to modify from 2 threads is confusing > > > > I think you're saying there's already a rule about modifying AVOptions from > > 2 threads. Could you explain that in more detail? > > Well, one way this can be argued is this: > Latest C draft: (but i doubt this is different) ISO/IEC 9899:2017 C17 > ballot N2176 > > "Two expression evaluations conflict if one of them modifies a memory > location and the other one > reads or modifies the same memory location" > > so if you have 2 threads and one writes into a int and another reads it at the > same time, the code is broken. > The code doing said act through some API doesnt become less broken > > Calling AVOption non re-rentrant because of that is false thats as if one > executed > strtok_r(a,b,c) with the VERY same a,b,c from 2 threads and then said > its not thread safe > > strtok_r() is thread safe and reentrant if its used correctly, so is AVOption [...]
Ok, how about if the patch avoided the word "reentrant" and just said: + * Note: AVOptions values should not be modified after a struct is initialized. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
