gistfile1.m

@implementation DTMutableCoreTextLayoutFrame
{
	NSUInteger _numberOfDrawingOperationsInParallel;
	NSConditionLock *_lock;
}

- (void)_incDrawingOperations
{
	[_lock lock];
	_numberOfDrawingOperationsInParallel++;
	[_lock unlockWithCondition:_numberOfDrawingOperationsInParallel];
}

- (void)_decDrawingOperations
{
	[_lock lock]
	_numberOfDrawingOperationsInParallel--;
	[_lock unlockWithCondition:_numberOfDrawingOperationsInParallel];
}


- (void)drawInContext:(CGContextRef)context options:(DTCoreTextLayoutFrameDrawingOptions)options
{
	[self _incDrawingOperations];
	
	[super drawInContext:context options:options];
	
	[self _decDrawingOperations];
}


- (void)replaceTextInRange:(NSRange)range withText:(NSAttributedString *)text dirtyRect:(CGRect *)dirtyRect
{
	[_lock lockWhenCondition:0];
		
	  // updates
		
	[_lock unlockWithCondition:0];
}


@end