add WEBP_DSP_INIT / WEBP_DSP_INIT_FUNC

this internalizes the init checks and provides stronger synchronization
with pthreads when available while still allowing VP8GetCPUInfo to be
modified (mostly for testing purposes). windows is left as is since a
critical section or mutex would cause a leak.

Change-Id: Ieb997e014f2805c0ae39c16f13337663521356f4
(cherry picked from commit d77bf512bd)

src/dec/vp8_dec.c

@@ -491,7 +491,7 @@ static int GetCoeffsAlt(VP8BitReader* const br,
   return 16;
 }
 
-WEBP_TSAN_IGNORE_FUNCTION static void InitGetCoeffs(void) {
+static WEBP_TSAN_IGNORE_FUNCTION void InitGetCoeffs(void) {
   if (GetCoeffs == NULL) {
     if (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kSlowSSSE3)) {
       GetCoeffs = GetCoeffsAlt;

src/dsp/alpha_processing.c

@@ -409,12 +409,7 @@ extern void WebPInitAlphaProcessingSSE2(void);
 extern void WebPInitAlphaProcessingSSE41(void);
 extern void WebPInitAlphaProcessingNEON(void);
 
-static volatile VP8CPUInfo alpha_processing_last_cpuinfo_used =
+WEBP_DSP_INIT_FUNC(WebPInitAlphaProcessing) {
-    (VP8CPUInfo)&alpha_processing_last_cpuinfo_used;
-
-WEBP_TSAN_IGNORE_FUNCTION void WebPInitAlphaProcessing(void) {
-  if (alpha_processing_last_cpuinfo_used == VP8GetCPUInfo) return;
-
   WebPMultARGBRow = WebPMultARGBRow_C;
   WebPMultRow = WebPMultRow_C;
   WebPApplyAlphaMultiply4444 = ApplyAlphaMultiply_16b_C;
@@ -474,6 +469,4 @@ WEBP_TSAN_IGNORE_FUNCTION void WebPInitAlphaProcessing(void) {
   assert(WebPPackRGB != NULL);
   assert(WebPHasAlpha8b != NULL);
   assert(WebPHasAlpha32b != NULL);
-
-  alpha_processing_last_cpuinfo_used = VP8GetCPUInfo;
 }

src/dsp/cost.c

@@ -378,12 +378,7 @@ extern void VP8EncDspCostInitMIPS32(void);
 extern void VP8EncDspCostInitMIPSdspR2(void);
 extern void VP8EncDspCostInitSSE2(void);
 
-static volatile VP8CPUInfo cost_last_cpuinfo_used =
+WEBP_DSP_INIT_FUNC(VP8EncDspCostInit) {
-    (VP8CPUInfo)&cost_last_cpuinfo_used;
-
-WEBP_TSAN_IGNORE_FUNCTION void VP8EncDspCostInit(void) {
-  if (cost_last_cpuinfo_used == VP8GetCPUInfo) return;
-
   VP8GetResidualCost = GetResidualCost_C;
   VP8SetResidualCoeffs = SetResidualCoeffs_C;
 
@@ -405,8 +400,6 @@ WEBP_TSAN_IGNORE_FUNCTION void VP8EncDspCostInit(void) {
     }
 #endif
   }
-
-  cost_last_cpuinfo_used = VP8GetCPUInfo;
 }
 
 //------------------------------------------------------------------------------

src/dsp/dec.c

@@ -741,12 +741,7 @@ extern void VP8DspInitMIPS32(void);
 extern void VP8DspInitMIPSdspR2(void);
 extern void VP8DspInitMSA(void);
 
-static volatile VP8CPUInfo dec_last_cpuinfo_used =
+WEBP_DSP_INIT_FUNC(VP8DspInit) {
-    (VP8CPUInfo)&dec_last_cpuinfo_used;
-
-WEBP_TSAN_IGNORE_FUNCTION void VP8DspInit(void) {
-  if (dec_last_cpuinfo_used == VP8GetCPUInfo) return;
-
   VP8InitClipTables();
 
 #if !WEBP_NEON_OMIT_C_CODE
@@ -889,6 +884,4 @@ WEBP_TSAN_IGNORE_FUNCTION void VP8DspInit(void) {
   assert(VP8PredChroma8[5] != NULL);
   assert(VP8PredChroma8[6] != NULL);
   assert(VP8DitherCombine8x8 != NULL);
-
-  dec_last_cpuinfo_used = VP8GetCPUInfo;
 }

src/dsp/dsp.h

@@ -141,6 +141,42 @@ extern "C" {
 #endif
 #endif
 
+#if defined(WEBP_USE_THREAD) && !defined(_WIN32)
+#include <pthread.h>  // NOLINT
+
+#define WEBP_DSP_INIT(func) do {                                    \
+  static volatile VP8CPUInfo func ## _last_cpuinfo_used =           \
+      (VP8CPUInfo)&func ## _last_cpuinfo_used;                      \
+  static pthread_mutex_t func ## _lock = PTHREAD_MUTEX_INITIALIZER; \
+  if (pthread_mutex_lock(&func ## _lock)) break;                    \
+  if (func ## _last_cpuinfo_used != VP8GetCPUInfo) func();          \
+  func ## _last_cpuinfo_used = VP8GetCPUInfo;                       \
+  (void)pthread_mutex_unlock(&func ## _lock);                       \
+} while (0)
+#else  // !(defined(WEBP_USE_THREAD) && !defined(_WIN32))
+#define WEBP_DSP_INIT(func) do {                                    \
+  static volatile VP8CPUInfo func ## _last_cpuinfo_used =           \
+      (VP8CPUInfo)&func ## _last_cpuinfo_used;                      \
+  if (func ## _last_cpuinfo_used == VP8GetCPUInfo) break;           \
+  func();                                                           \
+  func ## _last_cpuinfo_used = VP8GetCPUInfo;                       \
+} while (0)
+#endif  // defined(WEBP_USE_THREAD) && !defined(_WIN32)
+
+// Defines an Init + helper function that control multiple initialization of
+// function pointers / tables.
+/* Usage:
+   WEBP_DSP_INIT_FUNC(InitFunc) {
+     ...function body
+   }
+*/
+#define WEBP_DSP_INIT_FUNC(name)                             \
+  static WEBP_TSAN_IGNORE_FUNCTION void name ## _body(void); \
+  WEBP_TSAN_IGNORE_FUNCTION void name(void) {                \
+    WEBP_DSP_INIT(name ## _body);                            \
+  }                                                          \
+  static WEBP_TSAN_IGNORE_FUNCTION void name ## _body(void)
+
 #define WEBP_UBSAN_IGNORE_UNDEF
 #define WEBP_UBSAN_IGNORE_UNSIGNED_OVERFLOW
 #if defined(__clang__) && defined(__has_attribute)
@@ -196,7 +232,7 @@ WEBP_EXTERN VP8CPUInfo VP8GetCPUInfo;
 // avoiding a compiler warning.
 #define WEBP_DSP_INIT_STUB(func) \
   extern void func(void); \
-  WEBP_TSAN_IGNORE_FUNCTION void func(void) {}
+  void func(void) {}
 
 //------------------------------------------------------------------------------
 // Encoding

src/dsp/enc.c

@@ -740,12 +740,7 @@ extern void VP8EncDspInitMIPS32(void);
 extern void VP8EncDspInitMIPSdspR2(void);
 extern void VP8EncDspInitMSA(void);
 
-static volatile VP8CPUInfo enc_last_cpuinfo_used =
+WEBP_DSP_INIT_FUNC(VP8EncDspInit) {
-    (VP8CPUInfo)&enc_last_cpuinfo_used;
-
-WEBP_TSAN_IGNORE_FUNCTION void VP8EncDspInit(void) {
-  if (enc_last_cpuinfo_used == VP8GetCPUInfo) return;
-
   VP8DspInit();  // common inverse transforms
   InitTables();
 
@@ -838,6 +833,4 @@ WEBP_TSAN_IGNORE_FUNCTION void VP8EncDspInit(void) {
   assert(VP8EncQuantizeBlockWHT != NULL);
   assert(VP8Copy4x4 != NULL);
   assert(VP8Copy16x8 != NULL);
-
-  enc_last_cpuinfo_used = VP8GetCPUInfo;
 }

src/dsp/filters.c

@@ -238,12 +238,7 @@ extern void VP8FiltersInitMSA(void);
 extern void VP8FiltersInitNEON(void);
 extern void VP8FiltersInitSSE2(void);
 
-static volatile VP8CPUInfo filters_last_cpuinfo_used =
+WEBP_DSP_INIT_FUNC(VP8FiltersInit) {
-    (VP8CPUInfo)&filters_last_cpuinfo_used;
-
-WEBP_TSAN_IGNORE_FUNCTION void VP8FiltersInit(void) {
-  if (filters_last_cpuinfo_used == VP8GetCPUInfo) return;
-
   WebPUnfilters[WEBP_FILTER_NONE] = NULL;
 #if !WEBP_NEON_OMIT_C_CODE
   WebPUnfilters[WEBP_FILTER_HORIZONTAL] = HorizontalUnfilter_C;
@@ -289,6 +284,4 @@ WEBP_TSAN_IGNORE_FUNCTION void VP8FiltersInit(void) {
   assert(WebPFilters[WEBP_FILTER_HORIZONTAL] != NULL);
   assert(WebPFilters[WEBP_FILTER_VERTICAL] != NULL);
   assert(WebPFilters[WEBP_FILTER_GRADIENT] != NULL);
-
-  filters_last_cpuinfo_used = VP8GetCPUInfo;
 }

src/dsp/lossless.c

@@ -577,9 +577,6 @@ extern void VP8LDspInitNEON(void);
 extern void VP8LDspInitMIPSdspR2(void);
 extern void VP8LDspInitMSA(void);
 
-static volatile VP8CPUInfo lossless_last_cpuinfo_used =
-    (VP8CPUInfo)&lossless_last_cpuinfo_used;
-
 #define COPY_PREDICTOR_ARRAY(IN, OUT) do {                \
   (OUT)[0] = IN##0_C;                                     \
   (OUT)[1] = IN##1_C;                                     \
@@ -599,9 +596,7 @@ static volatile VP8CPUInfo lossless_last_cpuinfo_used =
   (OUT)[15] = IN##0_C;                                    \
 } while (0);
 
-WEBP_TSAN_IGNORE_FUNCTION void VP8LDspInit(void) {
+WEBP_DSP_INIT_FUNC(VP8LDspInit) {
-  if (lossless_last_cpuinfo_used == VP8GetCPUInfo) return;
-
   COPY_PREDICTOR_ARRAY(Predictor, VP8LPredictors)
   COPY_PREDICTOR_ARRAY(Predictor, VP8LPredictors_C)
   COPY_PREDICTOR_ARRAY(PredictorAdd, VP8LPredictorsAdd)
@@ -658,8 +653,6 @@ WEBP_TSAN_IGNORE_FUNCTION void VP8LDspInit(void) {
   assert(VP8LConvertBGRAToRGB565 != NULL);
   assert(VP8LMapColor32b != NULL);
   assert(VP8LMapColor8b != NULL);
-
-  lossless_last_cpuinfo_used = VP8GetCPUInfo;
 }
 #undef COPY_PREDICTOR_ARRAY
 

src/dsp/lossless_enc.c

@@ -863,12 +863,7 @@ extern void VP8LEncDspInitMIPS32(void);
 extern void VP8LEncDspInitMIPSdspR2(void);
 extern void VP8LEncDspInitMSA(void);
 
-static volatile VP8CPUInfo lossless_enc_last_cpuinfo_used =
+WEBP_DSP_INIT_FUNC(VP8LEncDspInit) {
-    (VP8CPUInfo)&lossless_enc_last_cpuinfo_used;
-
-WEBP_TSAN_IGNORE_FUNCTION void VP8LEncDspInit(void) {
-  if (lossless_enc_last_cpuinfo_used == VP8GetCPUInfo) return;
-
   VP8LDspInit();
 
 #if !WEBP_NEON_OMIT_C_CODE
@@ -1011,8 +1006,6 @@ WEBP_TSAN_IGNORE_FUNCTION void VP8LEncDspInit(void) {
   assert(VP8LPredictorsSub_C[13] != NULL);
   assert(VP8LPredictorsSub_C[14] != NULL);
   assert(VP8LPredictorsSub_C[15] != NULL);
-
-  lossless_enc_last_cpuinfo_used = VP8GetCPUInfo;
 }
 
 //------------------------------------------------------------------------------

src/dsp/rescaler.c

@@ -204,11 +204,7 @@ extern void WebPRescalerDspInitMIPSdspR2(void);
 extern void WebPRescalerDspInitMSA(void);
 extern void WebPRescalerDspInitNEON(void);
 
-static volatile VP8CPUInfo rescaler_last_cpuinfo_used =
+WEBP_DSP_INIT_FUNC(WebPRescalerDspInit) {
-    (VP8CPUInfo)&rescaler_last_cpuinfo_used;
-
-WEBP_TSAN_IGNORE_FUNCTION void WebPRescalerDspInit(void) {
-  if (rescaler_last_cpuinfo_used == VP8GetCPUInfo) return;
 #if !defined(WEBP_REDUCE_SIZE)
 #if !WEBP_NEON_OMIT_C_CODE
   WebPRescalerExportRowExpand = WebPRescalerExportRowExpand_C;
@@ -253,5 +249,4 @@ WEBP_TSAN_IGNORE_FUNCTION void WebPRescalerDspInit(void) {
   assert(WebPRescalerImportRowExpand != NULL);
   assert(WebPRescalerImportRowShrink != NULL);
 #endif   // WEBP_REDUCE_SIZE
-  rescaler_last_cpuinfo_used = VP8GetCPUInfo;
 }

src/dsp/ssim.c

@@ -139,12 +139,7 @@ VP8AccumulateSSEFunc VP8AccumulateSSE;
 
 extern void VP8SSIMDspInitSSE2(void);
 
-static volatile VP8CPUInfo ssim_last_cpuinfo_used =
+WEBP_DSP_INIT_FUNC(VP8SSIMDspInit) {
-    (VP8CPUInfo)&ssim_last_cpuinfo_used;
-
-WEBP_TSAN_IGNORE_FUNCTION void VP8SSIMDspInit(void) {
-  if (ssim_last_cpuinfo_used == VP8GetCPUInfo) return;
-
 #if !defined(WEBP_REDUCE_SIZE)
   VP8SSIMGetClipped = SSIMGetClipped_C;
   VP8SSIMGet = SSIMGet_C;
@@ -161,6 +156,4 @@ WEBP_TSAN_IGNORE_FUNCTION void VP8SSIMDspInit(void) {
     }
 #endif
   }
-
-  ssim_last_cpuinfo_used = VP8GetCPUInfo;
 }

src/dsp/upsampling.c

@@ -219,12 +219,7 @@ extern void WebPInitYUV444ConvertersMIPSdspR2(void);
 extern void WebPInitYUV444ConvertersSSE2(void);
 extern void WebPInitYUV444ConvertersSSE41(void);
 
-static volatile VP8CPUInfo upsampling_last_cpuinfo_used1 =
+WEBP_DSP_INIT_FUNC(WebPInitYUV444Converters) {
-    (VP8CPUInfo)&upsampling_last_cpuinfo_used1;
-
-WEBP_TSAN_IGNORE_FUNCTION void WebPInitYUV444Converters(void) {
-  if (upsampling_last_cpuinfo_used1 == VP8GetCPUInfo) return;
-
   WebPYUV444Converters[MODE_RGBA]      = WebPYuv444ToRgba_C;
   WebPYUV444Converters[MODE_BGRA]      = WebPYuv444ToBgra_C;
   WebPYUV444Converters[MODE_RGB]       = WebPYuv444ToRgb_C;
@@ -254,7 +249,6 @@ WEBP_TSAN_IGNORE_FUNCTION void WebPInitYUV444Converters(void) {
     }
 #endif
   }
-  upsampling_last_cpuinfo_used1 = VP8GetCPUInfo;
 }
 
 //------------------------------------------------------------------------------
@@ -266,12 +260,7 @@ extern void WebPInitUpsamplersNEON(void);
 extern void WebPInitUpsamplersMIPSdspR2(void);
 extern void WebPInitUpsamplersMSA(void);
 
-static volatile VP8CPUInfo upsampling_last_cpuinfo_used2 =
+WEBP_DSP_INIT_FUNC(WebPInitUpsamplers) {
-    (VP8CPUInfo)&upsampling_last_cpuinfo_used2;
-
-WEBP_TSAN_IGNORE_FUNCTION void WebPInitUpsamplers(void) {
-  if (upsampling_last_cpuinfo_used2 == VP8GetCPUInfo) return;
-
 #ifdef FANCY_UPSAMPLING
 #if !WEBP_NEON_OMIT_C_CODE
   WebPUpsamplers[MODE_RGBA]      = UpsampleRgbaLinePair_C;
@@ -333,7 +322,6 @@ WEBP_TSAN_IGNORE_FUNCTION void WebPInitUpsamplers(void) {
 #endif
 
 #endif  // FANCY_UPSAMPLING
-  upsampling_last_cpuinfo_used2 = VP8GetCPUInfo;
 }
 
 //------------------------------------------------------------------------------

src/dsp/yuv.c

@@ -75,12 +75,7 @@ extern void WebPInitSamplersSSE41(void);
 extern void WebPInitSamplersMIPS32(void);
 extern void WebPInitSamplersMIPSdspR2(void);
 
-static volatile VP8CPUInfo yuv_last_cpuinfo_used =
+WEBP_DSP_INIT_FUNC(WebPInitSamplers) {
-    (VP8CPUInfo)&yuv_last_cpuinfo_used;
-
-WEBP_TSAN_IGNORE_FUNCTION void WebPInitSamplers(void) {
-  if (yuv_last_cpuinfo_used == VP8GetCPUInfo) return;
-
   WebPSamplers[MODE_RGB]       = YuvToRgbRow;
   WebPSamplers[MODE_RGBA]      = YuvToRgbaRow;
   WebPSamplers[MODE_BGR]       = YuvToBgrRow;
@@ -116,7 +111,6 @@ WEBP_TSAN_IGNORE_FUNCTION void WebPInitSamplers(void) {
     }
 #endif  // WEBP_USE_MIPS_DSP_R2
   }
-  yuv_last_cpuinfo_used = VP8GetCPUInfo;
 }
 
 //-----------------------------------------------------------------------------
@@ -260,18 +254,13 @@ void (*WebPSharpYUVUpdateRGB)(const int16_t* ref, const int16_t* src,
 void (*WebPSharpYUVFilterRow)(const int16_t* A, const int16_t* B, int len,
                               const uint16_t* best_y, uint16_t* out);
 
-static volatile VP8CPUInfo rgba_to_yuv_last_cpuinfo_used =
-    (VP8CPUInfo)&rgba_to_yuv_last_cpuinfo_used;
-
 extern void WebPInitConvertARGBToYUVSSE2(void);
 extern void WebPInitConvertARGBToYUVSSE41(void);
 extern void WebPInitConvertARGBToYUVNEON(void);
 extern void WebPInitSharpYUVSSE2(void);
 extern void WebPInitSharpYUVNEON(void);
 
-WEBP_TSAN_IGNORE_FUNCTION void WebPInitConvertARGBToYUV(void) {
+WEBP_DSP_INIT_FUNC(WebPInitConvertARGBToYUV) {
-  if (rgba_to_yuv_last_cpuinfo_used == VP8GetCPUInfo) return;
-
   WebPConvertARGBToY = ConvertARGBToY_C;
   WebPConvertARGBToUV = WebPConvertARGBToUV_C;
 
@@ -316,6 +305,4 @@ WEBP_TSAN_IGNORE_FUNCTION void WebPInitConvertARGBToYUV(void) {
   assert(WebPSharpYUVUpdateY != NULL);
   assert(WebPSharpYUVUpdateRGB != NULL);
   assert(WebPSharpYUVFilterRow != NULL);
-
-  rgba_to_yuv_last_cpuinfo_used = VP8GetCPUInfo;
 }

src/enc/near_lossless_enc.c

@@ -146,6 +146,6 @@ int VP8ApplyNearLossless(const WebPPicture* const picture, int quality,
 
 // Define a stub to suppress compiler warnings.
 extern void VP8LNearLosslessStub(void);
-WEBP_TSAN_IGNORE_FUNCTION void VP8LNearLosslessStub(void) {}
+void VP8LNearLosslessStub(void) {}
 
 #endif  // (WEBP_NEAR_LOSSLESS == 1)

src/enc/picture_csp_enc.c

@@ -126,7 +126,7 @@ static WEBP_INLINE int LinearToGamma(uint32_t base_value, int shift) {
 
 #else
 
-static WEBP_TSAN_IGNORE_FUNCTION void InitGammaTables(void) {}
+static void InitGammaTables(void) {}
 static WEBP_INLINE uint32_t GammaToLinear(uint8_t v) { return v; }
 static WEBP_INLINE int LinearToGamma(uint32_t base_value, int shift) {
   return (int)(base_value << shift);
@@ -238,7 +238,7 @@ static WEBP_INLINE uint32_t LinearToGammaS(uint32_t value) {
 
 #else
 
-static WEBP_TSAN_IGNORE_FUNCTION void InitGammaTablesS(void) {}
+static void InitGammaTablesS(void) {}
 static WEBP_INLINE uint32_t GammaToLinearS(int v) {
   return (v << GAMMA_TO_LINEAR_BITS) / MAX_Y_T;
 }