[FFmpeg-cvslog] avcodec/jpeg2000dec: Constify slice threads' ptr to main context

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Sat Jul 23 06:14:10 2022 +0200| [a18c372390346d089580a18183115c8f8ef2d1ec] | committer: Andreas Rheinhardt

avcodec/jpeg2000dec: Constify slice threads' ptr to main context

Modifying the main context from a slice thread is (usually)
a data race, so it must not happen. So only use a pointer to const
to access the main context.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a18c372390346d089580a18183115c8f8ef2d1ec
---

 libavcodec/jpeg2000dec.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index 4823127758..503753c4d6 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -1679,7 +1679,7 @@ static void decode_refpass(Jpeg2000T1Context *t1, int width, int height,
                 }
 }
 
-static void decode_clnpass(Jpeg2000DecoderContext *s, Jpeg2000T1Context *t1,
+static void decode_clnpass(const Jpeg2000DecoderContext *s, Jpeg2000T1Context *t1,
                            int width, int height, int bpno, int bandno,
                            int seg_symbols, int vert_causal_ctx_csty_symbol)
 {
@@ -1745,7 +1745,7 @@ static void decode_clnpass(Jpeg2000DecoderContext *s, Jpeg2000T1Context *t1,
     }
 }
 
-static int decode_cblk(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty,
+static int decode_cblk(const Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty,
                        Jpeg2000T1Context *t1, Jpeg2000Cblk *cblk,
                        int width, int height, int bandpos, uint8_t roi_shift)
 {
@@ -1896,7 +1896,7 @@ static void dequantization_int_97(int x, int y, Jpeg2000Cblk *cblk,
     }
 }
 
-static inline void mct_decode(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile)
+static inline void mct_decode(const Jpeg2000DecoderContext *s, Jpeg2000Tile *tile)
 {
     int i, csize = 1;
     void *src[3];
@@ -1937,7 +1937,7 @@ static inline void roi_scale_cblk(Jpeg2000Cblk *cblk,
     }
 }
 
-static inline void tile_codeblocks(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile)
+static inline void tile_codeblocks(const Jpeg2000DecoderContext *s, Jpeg2000Tile *tile)
 {
     Jpeg2000T1Context t1;
 
@@ -2009,7 +2009,7 @@ static inline void tile_codeblocks(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile
 }
 
 #define WRITE_FRAME(D, PIXEL)                                                                     \
-    static inline void write_frame_ ## D(Jpeg2000DecoderContext * s, Jpeg2000Tile * tile,         \
+    static inline void write_frame_ ## D(const Jpeg2000DecoderContext * s, Jpeg2000Tile * tile,   \
                                          AVFrame * picture, int precision)                        \
     {                                                                                             \
         const AVPixFmtDescriptor *pixdesc = av_pix_fmt_desc_get(s->avctx->pix_fmt);               \
@@ -2078,7 +2078,7 @@ WRITE_FRAME(16, uint16_t)
 static int jpeg2000_decode_tile(AVCodecContext *avctx, void *td,
                                 int jobnr, int threadnr)
 {
-    Jpeg2000DecoderContext *s = avctx->priv_data;
+    const Jpeg2000DecoderContext *s = avctx->priv_data;
     AVFrame *picture = td;
     Jpeg2000Tile *tile = s->tile + jobnr;