Open Radar

 
# Summary:
CIContext render: API to memory buffer crashes when provided with a filter taking 2+ GL-based CIImage.

# Steps to Reproduce:
Here's the sample code. (imageA & imageB are GL texture-based, GL context is active, etc). Crashes in CIContext render: call.

	CIImage *imageA = [simage CIImage];
	CIImage *imageB = [rimage CIImage];
	CIFilter *filter = [CIFilter filterWithName:@"CIAreaAverage"];
	
	CIFilter *diffblend = [CIFilter filterWithName:@"CISubtractBlendMode"];
	CIImage *image = imageA;
	
	[diffblend setDefaults];
	[diffblend setValue:imageA forKey:kCIInputImageKey];
	[diffblend setValue:imageB forKey:kCIInputBackgroundImageKey];
	
	image = diffblend.outputImage;
	
	[filter setDefaults];
	[filter setValue:image forKey:kCIInputImageKey];
	[filter setValue:[CIVector vectorWithCGRect:image.extent] forKey:kCIInputExtentKey];
	image = filter.outputImage;
	
	float rgba[4] = {0.0};
		
	[self.CIContext render:image toBitmap:rgba rowBytes:4*sizeof(float) bounds:image.extent format:kCIFormatRGBAf colorSpace:NULL];
	EXLog(@"mean value: %f %f %f %f", rgba[0], rgba[1], rgba[2], rgba[3]);


# Expected Results:
Should not crash, & should output values in rgba mem buffer.

# Actual Results:
Crashed in render: call. Here's the stack trace. 

Thread 8Queue : NSOperationQueue 0x60300009d300 :: NSOperation 0x60400024fc90 (QOS: LEGACY) (serial)
#0	0x00007fff87e6586b in std::__1::__tree<std::__1::__value_type<void*, CI::source_info_t*>, std::__1::__map_value_compare<void*, std::__1::__value_type<void*, CI::source_info_t*>, std::__1::less<void*>, true>, std::__1::allocator<std::__1::__value_type<void*, CI::source_info_t*> > >::erase(std::__1::__tree_const_iterator<std::__1::__value_type<void*, CI::source_info_t*>, std::__1::__tree_node<std::__1::__value_type<void*, CI::source_info_t*>, void*>*, long>) ()
#1	0x00007fff87e644c8 in CI::TextureManager::remove_lru() ()
#2	0x00007fff87e642ca in CI::TextureManager::remove_all() ()
#3	0x00007fff87e92fbd in CI::GLContext::after_render() ()
#4	0x00007fff87d67793 in CI::_get_bitmap(CI::Context*, CI::Image*, CGRect, CGColorSpace*, CI::Bitmap*) ()
#5	0x00007fff87d673b9 in CI::image_get_bitmap(CI::Context*, CI::Image*, CGRect, CGColorSpace*, CI::Bitmap*, unsigned long) ()
#6	0x00007fff87d49c54 in -[CIContext render:toBitmap:rowBytes:bounds:format:colorSpace:] ()
#7	0x000000010016dae1 in -[HYRenderContext _measurePerfsSourceImage:renderedImage:context:] at /Users/raf/WorkArea/Creacode/Hydra/Hydra/Sources/HYRenderContext.m:1416
#8	0x0000000100178c55 in -[HYRenderContext _flatten:exposureRange:context:] at /Users/raf/WorkArea/Creacode/Hydra/Hydra/Sources/HYRenderContext.m:1772
#9	0x000000010017d2cd in __60-[HYRenderContext flattenImageForProject:completionHandler:]_block_invoke_2 at /Users/raf/WorkArea/Creacode/Hydra/Hydra/Sources/HYRenderContext.m:1882
#10	0x0000000100201f84 in __41-[HYOpenGLRenderContext renderWithBlock:]_block_invoke at /Users/raf/WorkArea/Creacode/Hydra/Hydra/Sources/HYOpenGLRenderContext.m:266
#11	0x000000010023767f in __29-[GLQueue executeBlock:wait:]_block_invoke at /Users/raf/WorkArea/Creacode/CeedGL/Sources/GLQueue.m:66
#12	0x00007fff8cfae29c in __NSBLOCKOPERATION_IS_CALLING_OUT_TO_A_BLOCK__ ()
#13	0x00007fff8cfae00c in -[NSBlockOperation main] ()
#14	0x00007fff8cfad2fb in -[__NSOperationInternal _start:] ()
#15	0x00007fff8cfacde7 in __NSOQSchedule_f ()
#16	0x00000001012105ce in asan_dispatch_call_block_and_release ()

Description of the image being rendered at the time of the crash.

(lldb) po image
<CIImage: 0x603000154810 extent [0 0 1 1]>
  color_matrix r=(1 0 0 0) g=(0 1 0 0) b=(0 0 1 0) a=(0 0 0 1.67167) extent=[0 0 1 1]
    kernel _areaAvg8(image) extent=[0 0 1 1]
      kernel _areaAvg8(image) extent=[0 0 8 6]
        kernel _areaAvg8(image) extent=[0 0 61 41]
          kernel _areaAvg8(image) extent=[0 0 484 324]
            colorkernel _subtractBlendMode(uCf,uCb) extent=[0 0 3872 2592]
              unpremultiply extent=[0 0 3872 2592]
                GLTexture 10 extent=[0 0 3872 2592]
              unpremultiply extent=[0 0 3872 2592]
                GLTexture 26 extent=[0 0 3872 2592]

(lldb) po self.CIContext
<CIContext: 0x60200003c0d0 (2) GLContext=0x628000000100>


# Regression:
Any Mac running OS El Capitan.

# Notes:
Both GL textures are perfectly valid at the time of render, and appropriate context is active (single thread).
If I use only one GL texture-based CIImage -> it does not crash.