From 218d1f76d46fc5b59a27d5ec9e88e821dc888d11 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Thu, 27 Jan 2022 15:53:48 +0100 Subject: avcodec/jpeg2000dec: Move preparations to main thread, fix race jpeg2000_decode_tile() (which is run concurrently by several threads when using slice threading) currently modifies some joint values before doing its actual work. This is a data race that happens to work because all threads set the same values; but it is nevertheless undefined behaviour. Fix this by performing said preparatory work in the main thread instead. This fixes the vsynth(1|2|_lena)-jpeg2000(-97)? FATE-tests when using TSAN and slice threading. Signed-off-by: Andreas Rheinhardt --- libavcodec/jpeg2000dec.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c index 80b2e2d627..a7eb809f30 100644 --- a/libavcodec/jpeg2000dec.c +++ b/libavcodec/jpeg2000dec.c @@ -2080,7 +2080,6 @@ static int jpeg2000_decode_tile(AVCodecContext *avctx, void *td, Jpeg2000DecoderContext *s = avctx->priv_data; AVFrame *picture = td; Jpeg2000Tile *tile = s->tile + jobnr; - int x; tile_codeblocks(s, tile); @@ -2088,17 +2087,6 @@ static int jpeg2000_decode_tile(AVCodecContext *avctx, void *td, if (tile->codsty[0].mct) mct_decode(s, tile); - for (x = 0; x < s->ncomponents; x++) { - if (s->cdef[x] < 0) { - for (x = 0; x < s->ncomponents; x++) { - s->cdef[x] = x + 1; - } - if ((s->ncomponents & 1) == 0) - s->cdef[s->ncomponents-1] = 0; - break; - } - } - if (s->precision <= 8) { write_frame_8(s, tile, picture, 8); } else { @@ -2537,6 +2525,17 @@ static int jpeg2000_decode_frame(AVCodecContext *avctx, void *data, if (ret = jpeg2000_read_bitstream_packets(s)) goto end; + for (int x = 0; x < s->ncomponents; x++) { + if (s->cdef[x] < 0) { + for (x = 0; x < s->ncomponents; x++) { + s->cdef[x] = x + 1; + } + if ((s->ncomponents & 1) == 0) + s->cdef[s->ncomponents-1] = 0; + break; + } + } + avctx->execute2(avctx, jpeg2000_decode_tile, picture, NULL, s->numXtiles * s->numYtiles); jpeg2000_dec_cleanup(s); -- cgit v1.2.3