BLF: Mutex Lock Glyph Cache Per Font, Not Global

Only lock access to our glyph caches per-font, rather than globally.
Also upgrade from spinlocks to mutexes.

See D15644 for more details.

Differential Revision: https://developer.blender.org/D15644

Reviewed by Brecht Van Lommel

source/blender/blenfont/intern/blf_font.c

@@ -56,8 +56,8 @@ BatchBLF g_batch;
 /* freetype2 handle ONLY for this file! */
 static FT_Library ft_lib = NULL;
 
-static SpinLock ft_lib_mutex;
-static SpinLock blf_glyph_cache_mutex;
+/* Lock for FreeType library, used around face creation and deletion.  */
+static ThreadMutex ft_lib_mutex;
 
 /* May be set to #UI_widgetbase_draw_cache_flush. */
 static void (*blf_draw_cache_flush)(void) = NULL;
@@ -1162,19 +1162,17 @@ char *blf_display_name(FontBLF *font)
 int blf_font_init(void)
 {
   memset(&g_batch, 0, sizeof(g_batch));
-  BLI_spin_init(&ft_lib_mutex);
-  BLI_spin_init(&blf_glyph_cache_mutex);
+  BLI_mutex_init(&ft_lib_mutex);
   int err = FT_Init_FreeType(&ft_lib);
   return err;
 }
 
 void blf_font_exit(void)
 {
-  BLI_spin_end(&ft_lib_mutex);
+  BLI_mutex_end(&ft_lib_mutex);
   if (ft_lib) {
     FT_Done_FreeType(ft_lib);
   }
-  BLI_spin_end(&blf_glyph_cache_mutex);
   blf_batch_draw_exit();
 }
 
@@ -1233,8 +1231,6 @@ static void blf_font_fill(FontBLF *font)
   font->buf_info.col_init[3] = 0;
 
   font->ft_lib = ft_lib;
-  font->ft_lib_mutex = &ft_lib_mutex;
-  font->glyph_cache_mutex = &blf_glyph_cache_mutex;
 }
 
 /**
@@ -1252,12 +1248,14 @@ bool blf_ensure_face(FontBLF *font)
 
   FT_Error err;
 
+  BLI_mutex_lock(&ft_lib_mutex);
   if (font->filepath) {
     err = FT_New_Face(ft_lib, font->filepath, 0, &font->face);
   }
   if (font->mem) {
     err = FT_New_Memory_Face(ft_lib, font->mem, (FT_Long)font->mem_size, 0, &font->face);
   }
+  BLI_mutex_unlock(&ft_lib_mutex);
 
   if (err) {
     if (ELEM(err, FT_Err_Unknown_File_Format, FT_Err_Unimplemented_Feature)) {
@@ -1384,6 +1382,8 @@ static FontBLF *blf_font_new_ex(const char *name,
   }
   blf_font_fill(font);
 
+  BLI_mutex_init(&font->glyph_cache_mutex);
+
   /* If we have static details about this font we don't need to load the Face. */
   const eFaceDetails *static_details = NULL;
   char filename[256];
@@ -1450,7 +1450,9 @@ void blf_font_free(FontBLF *font)
   }
 
   if (font->face) {
+    BLI_mutex_lock(&ft_lib_mutex);
     FT_Done_Face(font->face);
+    BLI_mutex_unlock(&ft_lib_mutex);
     font->face = NULL;
   }
   if (font->filepath) {
@@ -1459,6 +1461,9 @@ void blf_font_free(FontBLF *font)
   if (font->name) {
     MEM_freeN(font->name);
   }
+
+  BLI_mutex_end(&font->glyph_cache_mutex);
+
   MEM_freeN(font);
 }
 

source/blender/blenfont/intern/blf_glyph.c

@@ -115,7 +115,7 @@ static GlyphCacheBLF *blf_glyph_cache_new(FontBLF *font)
 
 GlyphCacheBLF *blf_glyph_cache_acquire(FontBLF *font)
 {
-  BLI_spin_lock(font->glyph_cache_mutex);
+  BLI_mutex_lock(&font->glyph_cache_mutex);
 
   GlyphCacheBLF *gc = blf_glyph_cache_find(font, font->size, font->dpi);
 
@@ -128,7 +128,7 @@ GlyphCacheBLF *blf_glyph_cache_acquire(FontBLF *font)
 
 void blf_glyph_cache_release(FontBLF *font)
 {
-  BLI_spin_unlock(font->glyph_cache_mutex);
+  BLI_mutex_unlock(&font->glyph_cache_mutex);
 }
 
 static void blf_glyph_cache_free(GlyphCacheBLF *gc)
@@ -152,13 +152,13 @@ void blf_glyph_cache_clear(FontBLF *font)
 {
   GlyphCacheBLF *gc;
 
-  BLI_spin_lock(font->glyph_cache_mutex);
+  BLI_mutex_lock(&font->glyph_cache_mutex);
 
   while ((gc = BLI_pophead(&font->cache))) {
     blf_glyph_cache_free(gc);
   }
 
-  BLI_spin_unlock(font->glyph_cache_mutex);
+  BLI_mutex_unlock(&font->glyph_cache_mutex);
 }
 
 /**

source/blender/blenfont/intern/blf_internal_types.h

@@ -323,9 +323,6 @@ typedef struct FontBLF {
   /* freetype2 lib handle. */
   FT_Library ft_lib;
 
-  /* Mutex lock for library */
-  SpinLock *ft_lib_mutex;
-
   /* freetype2 face. */
   FT_Face face;
 
@@ -339,7 +336,7 @@ typedef struct FontBLF {
   FontBufInfoBLF buf_info;
 
   /* Mutex lock for glyph cache. */
-  SpinLock *glyph_cache_mutex;
+  ThreadMutex glyph_cache_mutex;
 } FontBLF;
 
 typedef struct DirBLF {