Opal: add locking to OPFreeTypeFont around FT calls so it is threadsafe (NSFont is required to be)

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/opal/trunk@32792 72102866-910b-0410-8b05-ffd578937521
2024-11-23 12:19:49 +00:00 · 2011-04-06 19:49:01 +00:00 · 2011-04-06 19:49:01 +00:00 · df3134ede3
commit df3134ede3
parent 303520115c
2 changed files with 105 additions and 16 deletions
--- a/Source/OpalText/FreeType/OPFreeTypeFont.h
+++ b/Source/OpalText/FreeType/OPFreeTypeFont.h
@ -31,6 +31,12 @@
@interface OPFreeTypeFont: NSFont
 {
  FT_Face fontFace;
+  /**
+   * NSFont can be used simultaneously by multiple threads, so it is
+   * necessary to lock before we call FreeType, because an FT_Face
+   * object may be used by only one thread.
+   */
+  NSLock *fontFaceLock;
  BOOL isType1;
  NSCache *tableCache;
 }
--- a/Source/OpalText/FreeType/OPFreeTypeFont.m
+++ b/Source/OpalText/FreeType/OPFreeTypeFont.m
@ -49,7 +49,7 @@
 #ifndef NSRectFromCGRect
 #define NSRectFromCGRect(r) NSMakeRect(r.origin.x, r.origin.y, r.size.width, r.size.height)
 #endif
-static FT_Library OPFreeTypeLibrary = 0;
+static const NSString *kOPFreeTypeLibrary = @"OPFreeTypeLibrary";


@interface NSObject (NSFontconfigFontDescriptorInternals)
@ -58,17 +58,24 @@ static FT_Library OPFreeTypeLibrary = 0;
@end

@implementation OPFreeTypeFont
-+ (void)initialize
+
+- (FT_Library)currentThreadFreeTypeLibrary
 {
-  if ([OPFreeTypeFont class] == self)
+  NSMutableDictionary *threadDict = [[NSThread currentThread] threadDictionary];
+ 
+  if (nil == [threadDict objectForKey: kOPFreeTypeLibrary])
  {
-    NSInteger error = FT_Init_FreeType(&OPFreeTypeLibrary);
+    FT_Library library = NULL;
+    NSInteger error = FT_Init_FreeType(&library);
    if (0 != error)
    {
      [NSException raise: @"OTFontSystemException"
                  format: @"An error (%ld) occurred when initializing the FreeType library.", error];
    }
+    [threadDict setObject: [NSValue valueWithPointer: library] forKey: kOPFreeTypeLibrary];
  }
+
+  return [[threadDict objectForKey: kOPFreeTypeLibrary] pointerValue];
 }

 - (id)_initWithDescriptor: (NSFontDescriptor*)aDescriptor
@ -106,7 +113,7 @@ static FT_Library OPFreeTypeLibrary = 0;
    return nil;
  }

-  error = FT_New_Face(OPFreeTypeLibrary, path, faceIndex, &fontFace);
+  error = FT_New_Face([self currentThreadFreeTypeLibrary], path, faceIndex, &fontFace);
  if (0 != error)
  {
    NSWarnMLog(@"Could not initialize freetype font (error: %ld)",
@ -146,9 +153,14 @@ static FT_Library OPFreeTypeLibrary = 0;
  FT_Vector vector = FT_VectorQ1616FromCGAffineTransform(_matrix.CGTransform);
  FT_Set_Transform(fontFace, &matrix, &vector);
  //FIXME: Do more stuff
+
+  fontFaceLock = [[NSLock alloc] init];
+
  return self;
 }

+// FIXME: Implement -dealloc?
+
 - (BOOL)attachMetricsForFontAtPath: (NSString*)path
 {
  NSString *extension = [[path pathExtension] lowercaseString];
@ -194,10 +206,12 @@ static FT_Library OPFreeTypeLibrary = 0;
  }

  // First, run with a NULL pointer for the buffer to obtain the length needed.
+  [fontFaceLock lock];
  error = FT_Load_Sfnt_Table(fontFace, tag, 0, NULL, &length);

  if (0 != error)
  {
+    [fontFaceLock unlock];
    return nil;
  }

@ -205,12 +219,15 @@ static FT_Library OPFreeTypeLibrary = 0;
  buffer = malloc(length);
  if (NULL == buffer)
  {
+    [fontFaceLock unlock];
    return nil;
  }

  // Now load the table into the buffer:
  error = FT_Load_Sfnt_Table(fontFace, tag, 0, buffer, &length);

+  [fontFaceLock unlock];
+
  if (0 != error)
  {
    // Oops, we could not fill the buffer, so we throw it away.
@ -255,17 +272,30 @@ static FT_Library OPFreeTypeLibrary = 0;

 - (CGFloat)unitsPerEm
 {
-  return (CGFloat)fontFace->units_per_EM;
+  [fontFaceLock lock];
+  CGFloat result = (CGFloat)fontFace->units_per_EM;
+  [fontFaceLock unlock];
+
+  return result;
 }

 - (CGFloat)ascender
 {
-  return ((fontFace->ascender * [_descriptor pointSize]) / (CGFloat)fontFace->units_per_EM);
+  [fontFaceLock lock];
+  CGFloat result = ((fontFace->ascender * [_descriptor pointSize]) / (CGFloat)fontFace->units_per_EM);
+  [fontFaceLock unlock];
+
+  return result;
 }

+
 - (CGFloat)descender
 {
-  return ((fontFace->descender * [_descriptor pointSize]) / (CGFloat)fontFace->units_per_EM);
+  [fontFaceLock lock];
+  CGFloat result = ((fontFace->descender * [_descriptor pointSize]) / (CGFloat)fontFace->units_per_EM);
+  [fontFaceLock unlock];
+
+  return result;
 }

 /* TODO: If this kind of method is too slow, we will have to cache the results
@ -274,24 +304,34 @@ static FT_Library OPFreeTypeLibrary = 0;
 - (CGFloat)capHeight
 {
  FT_Short rawCapHeight = 0;
+
+  [fontFaceLock lock];
  TT_OS2* OS2Table = FT_Get_Sfnt_Table(fontFace, TTAG_OS2);
  if (NULL == OS2Table)
  {
+    [fontFaceLock unlock];
    return 0;
  }
  rawCapHeight = OS2Table->sCapHeight;
+  [fontFaceLock unlock];
+
  return TRANSFORMED_SIZE(0, rawCapHeight).height;
 }

 - (CGFloat)xHeight
 {
  FT_Short rawXHeight = 0;
+
+  [fontFaceLock lock];
  TT_OS2* OS2Table = FT_Get_Sfnt_Table(fontFace, TTAG_OS2);
  if (NULL == OS2Table)
  {
+    [fontFaceLock unlock];
    return 0;
  }
  rawXHeight = OS2Table->sxHeight;
+  [fontFaceLock unlock];
+
  return TRANSFORMED_SIZE(0, rawXHeight).height;

 }
@ -300,24 +340,32 @@ static FT_Library OPFreeTypeLibrary = 0;
 {
  BOOL isFixedPitch = NO;

+  [fontFaceLock lock];
  TT_Postscript *postTable = FT_Get_Sfnt_Table(fontFace, TTAG_post);
  if (NULL == postTable)
  {
+    [fontFaceLock unlock];
    return NO;
  }
  isFixedPitch = postTable->isFixedPitch;
+  [fontFaceLock unlock];
+
  return isFixedPitch;
 }

 - (CGFloat)italicAngle
 {
  FT_Fixed rawItalicAngle = 0;
+  [fontFaceLock lock];
  TT_Postscript *postTable = FT_Get_Sfnt_Table(fontFace, TTAG_post);
  if (NULL == postTable)
  {
+    [fontFaceLock unlock];
    return 0;
  }
  rawItalicAngle = postTable->italicAngle;
+  [fontFaceLock unlock];
+
  return CGFloatFromFT_Fixed(rawItalicAngle);
 }

@ -329,12 +377,17 @@ static FT_Library OPFreeTypeLibrary = 0;
   * to be identical.
   */
  FT_Short rawLineGap = 0;
+
+  [fontFaceLock lock];
  TT_HoriHeader *hheaTable = FT_Get_Sfnt_Table(fontFace, TTAG_hhea);
  if (NULL == hheaTable)
  {
+    [fontFaceLock unlock];
    return 0;
  }
  rawLineGap = hheaTable->Line_Gap;
+  [fontFaceLock unlock];
+
  return TRANSFORMED_SIZE(0, rawLineGap).height;
 }

@ -343,7 +396,11 @@ static FT_Library OPFreeTypeLibrary = 0;
  /*
   * FIXME: We should make this conditional on horizontal/vertical orientation.
   */
-  return NSMakeSize(REAL_SIZE(fontFace->max_advance_width), REAL_SIZE(fontFace->max_advance_height));
+  [fontFaceLock lock];
+  NSSize size = NSMakeSize(REAL_SIZE(fontFace->max_advance_width), REAL_SIZE(fontFace->max_advance_height));
+  [fontFaceLock unlock];
+
+  return size;
 }

 - (NSSize)minimumAdvancement
@ -353,33 +410,48 @@ static FT_Library OPFreeTypeLibrary = 0;
   * FIXME2: We should make this conditional on horizontal/vertical orientation.
   * FIXME3: Does FreeType apply the transform to the bounding box?
   */
-  return NSMakeSize(REAL_SIZE((fontFace->bbox).xMin),
+  [fontFaceLock lock];
+  NSSize size = NSMakeSize(REAL_SIZE((fontFace->bbox).xMin),
    REAL_SIZE((fontFace->bbox).yMin));
+  [fontFaceLock unlock];
+
+  return size;
 }

 - (NSUInteger)numberOfGlyphs
 {
-  return fontFace->num_glyphs;
+  [fontFaceLock lock];
+  NSUInteger result = fontFace->num_glyphs;
+  [fontFaceLock unlock];
+  return result;
 }

 - (CGFloat)underlinePosition
 {
+  [fontFaceLock lock];
  TT_Postscript *postTable = FT_Get_Sfnt_Table(fontFace, TTAG_post);
  if (NULL == postTable)
  {
+    [fontFaceLock unlock];
    return 0;
  }
-  return TRANSFORMED_SIZE(0, postTable->underlinePosition).height;
+  CGFloat position = TRANSFORMED_SIZE(0, postTable->underlinePosition).height;
+  [fontFaceLock unlock];
+  return position;
 }

 - (CGFloat)underlineThickness
 {
+  [fontFaceLock lock];
  TT_Postscript *postTable = FT_Get_Sfnt_Table(fontFace, TTAG_post);
  if (NULL == postTable)
  {
+    [fontFaceLock unlock];
    return 0;
  }
-  return TRANSFORMED_SIZE(0, postTable->underlineThickness).height;
+  CGFloat thickness = TRANSFORMED_SIZE(0, postTable->underlineThickness).height;
+  [fontFaceLock unlock];
+  return thickness;
 }

 - (NSSize)advancementForGlyph: (NSGlyph)glyph
@ -388,10 +460,13 @@ static FT_Library OPFreeTypeLibrary = 0;
  {
    return NSMakeSize(0, 0);
  }
+  [fontFaceLock lock];
  FT_Load_Glyph(fontFace, glyph, FT_LOAD_DEFAULT);
-  return NSMakeSize(REAL_SIZE(fontFace->glyph->linearHoriAdvance),
+  NSSize size = NSMakeSize(REAL_SIZE(fontFace->glyph->linearHoriAdvance),
    REAL_SIZE(fontFace->glyph->linearVertAdvance));
+  [fontFaceLock unlock];

+  return size;
  /*
   * FIXME: Add fast path for integer rendering modes. We don't need to do
   * so many integer->float conversions then.
@ -454,10 +529,13 @@ static FT_Library OPFreeTypeLibrary = 0;
 {
  //FIXME: Determine whether FreeType already transforms the bounding box for
  //us.
+  [fontFaceLock lock];
  CGFloat originX = REAL_SIZE((fontFace->bbox).xMin);
  CGFloat originY = REAL_SIZE((fontFace->bbox).yMin);
  CGFloat sizeX = (REAL_SIZE((fontFace->bbox).xMax) - originX);
  CGFloat sizeY = (REAL_SIZE((fontFace->bbox).yMax) - originY);
+  [fontFaceLock unlock];
+
  return NSMakeRect(originX, originY, sizeX, sizeY);
 }

@ -468,12 +546,15 @@ static FT_Library OPFreeTypeLibrary = 0;
  {
    return NSMakeRect(0, 0, 0, 0);
  }
+
+  [fontFaceLock lock];
  FT_Load_Glyph(fontFace, glyph, FT_LOAD_DEFAULT);
-  return NSRectFromCGRect(TRANSFORMED_RECT(fontFace->glyph->metrics.horiBearingX,
+  NSRect result = NSRectFromCGRect(TRANSFORMED_RECT(fontFace->glyph->metrics.horiBearingX,
    fontFace->glyph->metrics.horiBearingY,
    fontFace->glyph->metrics.width,
    fontFace->glyph->metrics.height));
-
+  [fontFaceLock unlock];
+  return result;
 }

 - (void)getBoundingRects: (NSRectArray)rects
@ -497,7 +578,9 @@ static FT_Library OPFreeTypeLibrary = 0;

 - (NSGlyph)glyphWithName: (NSString*)name
 {
+  [fontFaceLock lock];
  FT_UInt glyph = FT_Get_Name_Index(fontFace, (FT_String*)[name UTF8String]);
+  [fontFaceLock unlock];
  if(0 == glyph)
  {
    return NSNullGlyph;