Andrew Sayers: > 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.
This is wrong either. As Paul has already pointed out to you, some options are allowed to be modified lateron. - Andreas _______________________________________________ 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".
