[FFmpeg-devel] [PATCH 27/39] avcodec/ituh263enc: Make static initializations thread-safe

[Andreas Rheinhardt]

This already makes several encoders (namely FLV, H.263, H.263+ and
RealVideo 1.0 and 2.0) that use this init-threadsafe.

It also makes the Snow encoder init-threadsafe; it was already marked
as such since commit d49210788b0836d56dd872d517fe73f83b080101, because
it was thought to be harmless if one and the same object was
initialized by multiple threads at the same time.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
---
 libavcodec/flvenc.c        |  2 +-
 libavcodec/ituh263enc.c    | 28 ++++++++++++++++------------
 libavcodec/mpegvideo_enc.c |  4 ++--
 libavcodec/rv10enc.c       |  2 +-
 libavcodec/rv20enc.c       |  2 +-
 5 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/libavcodec/flvenc.c b/libavcodec/flvenc.c
index b85e4667c4..9429862159 100644
--- a/libavcodec/flvenc.c
+++ b/libavcodec/flvenc.c
@@ -107,7 +107,7 @@ AVCodec ff_flv_encoder = {
     .init           = ff_mpv_encode_init,
     .encode2        = ff_mpv_encode_picture,
     .close          = ff_mpv_encode_end,
-    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
     .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P,
                                                      AV_PIX_FMT_NONE},
     .priv_class     = &flv_class,
diff --git a/libavcodec/ituh263enc.c b/libavcodec/ituh263enc.c
index 43260e6984..79c8c9999e 100644
--- a/libavcodec/ituh263enc.c
+++ b/libavcodec/ituh263enc.c
@@ -30,6 +30,7 @@
 #include <limits.h>
 
 #include "libavutil/attributes.h"
+#include "libavutil/thread.h"
 #include "avcodec.h"
 #include "mpegvideo.h"
 #include "mpegvideodata.h"
@@ -671,7 +672,7 @@ void ff_h263_encode_motion(PutBitContext *pb, int val, int f_code)
     }
 }
 
-static av_cold void init_mv_penalty_and_fcode(MpegEncContext *s)
+static av_cold void init_mv_penalty_and_fcode(void)
 {
     int f_code;
     int mv;
@@ -754,22 +755,23 @@ static av_cold void init_uni_h263_rl_tab(const RLTable *rl, uint8_t *len_tab)
     }
 }
 
-av_cold void ff_h263_encode_init(MpegEncContext *s)
+static av_cold void h263_encode_init_static(void)
 {
-    static int done = 0;
+    static uint8_t rl_intra_table[2][2 * MAX_RUN + MAX_LEVEL + 3];
 
-    if (!done) {
-        static uint8_t rl_intra_table[2][2 * MAX_RUN + MAX_LEVEL + 3];
-        done = 1;
+    ff_rl_init(&ff_rl_intra_aic, rl_intra_table);
+    ff_h263_init_rl_inter();
 
-        ff_rl_init(&ff_rl_intra_aic, rl_intra_table);
-        ff_h263_init_rl_inter();
+    init_uni_h263_rl_tab(&ff_rl_intra_aic,  uni_h263_intra_aic_rl_len);
+    init_uni_h263_rl_tab(&ff_h263_rl_inter, uni_h263_inter_rl_len);
 
-        init_uni_h263_rl_tab(&ff_rl_intra_aic,  uni_h263_intra_aic_rl_len);
-        init_uni_h263_rl_tab(&ff_h263_rl_inter, uni_h263_inter_rl_len);
+    init_mv_penalty_and_fcode();
+}
+
+av_cold void ff_h263_encode_init(MpegEncContext *s)
+{
+    static AVOnce init_static_once = AV_ONCE_INIT;
 
-        init_mv_penalty_and_fcode(s);
-    }
     s->me.mv_penalty= mv_penalty; // FIXME exact table for MSMPEG4 & H.263+
 
     s->intra_ac_vlc_length     =s->inter_ac_vlc_length     = uni_h263_inter_rl_len;
@@ -817,6 +819,8 @@ av_cold void ff_h263_encode_init(MpegEncContext *s)
         s->y_dc_scale_table=
         s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
     }
+
+    ff_thread_once(&init_static_once, h263_encode_init_static);
 }
 
 void ff_h263_encode_mba(MpegEncContext *s)
diff --git a/libavcodec/mpegvideo_enc.c b/libavcodec/mpegvideo_enc.c
index 061081db08..8fb415f42b 100644
--- a/libavcodec/mpegvideo_enc.c
+++ b/libavcodec/mpegvideo_enc.c
@@ -4786,7 +4786,7 @@ AVCodec ff_h263_encoder = {
     .init           = ff_mpv_encode_init,
     .encode2        = ff_mpv_encode_picture,
     .close          = ff_mpv_encode_end,
-    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
     .pix_fmts= (const enum AVPixelFormat[]){AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE},
     .priv_class     = &h263_class,
 };
@@ -4816,7 +4816,7 @@ AVCodec ff_h263p_encoder = {
     .encode2        = ff_mpv_encode_picture,
     .close          = ff_mpv_encode_end,
     .capabilities   = AV_CODEC_CAP_SLICE_THREADS,
-    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
     .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE },
     .priv_class     = &h263p_class,
 };
diff --git a/libavcodec/rv10enc.c b/libavcodec/rv10enc.c
index 42316836c5..6add8e4dd1 100644
--- a/libavcodec/rv10enc.c
+++ b/libavcodec/rv10enc.c
@@ -79,7 +79,7 @@ AVCodec ff_rv10_encoder = {
     .init           = ff_mpv_encode_init,
     .encode2        = ff_mpv_encode_picture,
     .close          = ff_mpv_encode_end,
-    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
     .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE },
     .priv_class     = &rv10_class,
 };
diff --git a/libavcodec/rv20enc.c b/libavcodec/rv20enc.c
index d9d63d4d9c..95f90389bc 100644
--- a/libavcodec/rv20enc.c
+++ b/libavcodec/rv20enc.c
@@ -76,7 +76,7 @@ AVCodec ff_rv20_encoder = {
     .init           = ff_mpv_encode_init,
     .encode2        = ff_mpv_encode_picture,
     .close          = ff_mpv_encode_end,
-    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
     .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE },
     .priv_class     = &rv20_class,
 };
-- 
2.25.1