Quoting Andreas Rheinhardt (2022-01-13 14:59:49) > Anton Khirnov: > > The API currently allows creating FIFOs up to > > - UINT_MAX: av_fifo_alloc(), av_fifo_realloc(), av_fifo_grow() > > - SIZE_MAX: av_fifo_alloc_array() > > However the usable limit is determined by > > - rndx/wndx being uint32_t > > - av_fifo_[size,space] returning int > > so no FIFO should be larger than the smallest of > > - INT_MAX > > - UINT32_MAX > > - SIZE_MAX > > (which should be INT_MAX an all commonly used platforms). > > Return an error on trying to allocate FIFOs larger than this limit. > > --- > > libavutil/fifo.c | 14 +++++++++++++- > > 1 file changed, 13 insertions(+), 1 deletion(-) > > > > diff --git a/libavutil/fifo.c b/libavutil/fifo.c > > index d741bdd395..f2f046b1f3 100644 > > --- a/libavutil/fifo.c > > +++ b/libavutil/fifo.c > > @@ -20,14 +20,23 @@ > > * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA > > 02110-1301 USA > > */ > > > > +#include <stdint.h> > > + > > #include "avassert.h" > > #include "common.h" > > #include "fifo.h" > > > > +#define FIFO_SIZE_MAX FFMIN3((uint64_t)INT_MAX, (uint64_t)UINT32_MAX, > > (uint64_t)SIZE_MAX) > > Aren't these casts unnecessary?
Possibly yes. I mainly added them so that FIFO_SIZE_MAX is always the same type, which might prevent surprises. I can drop the casts if you think they are never necessary. > And actually dangerous? (They add the implicit requirement that > INT_MAX and SIZE_MAX fit into an uint64_t.) I'll grant you _theoretically_ dangerous - I've never heard of a posix-compliant platform with sizeof(int) > 64. And in any case that macro should be gone with the old API (was going to include a patch scheduling its removal, but apparently forgot - will send it later). -- Anton Khirnov _______________________________________________ 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".
