Call to CIContext.FromOptions crashes in iOS - xamarin.ios

Question

In my Xamarin iOS app, I continuously receive CIImage instances that I need to convert to CGImage instance. Here is the relevant code:
CIContext cicontext = CIContext.FromOptions(null);
CGImage cgimage = cicontext.CreateCGImage(ciimage, ciimage.Extent);
...
cgimage.Dispose();
cicontext.Dispose();
Things work fine for the first 100 or so calls. After that, I get a crash in the application. Here is the stack trace:
critical: 2 libsystem_platform.dylib 0x21866077 _sigtramp + 42
critical: 3 CoreImage 0x24a352b9 <redacted> + 64
critical: 4 CoreImage 0x24a6c005 <redacted> + 292
critical: 5 CoreImage 0x24a6c237 <redacted> + 18
critical: 6 CoreImage 0x24a4b431 <redacted> + 512
critical: 7 CoreImage 0x24a47d5b <redacted> + 734
critical: 8 CoreImage 0x24a47a55 <redacted> + 52
critical: 9 MyApp 0x00fa4eb4 wrapper_managed_to_native_ObjCRuntime_Messaging_IntPtr_objc_msgSend_IntPtr_intptr_intptr_intptr + 108
critical: 10 MyApp 0x00f41a5c CoreImage_CIContext_FromOptions_Foundation_NSDictionary + 120
critical: 11 MyApp 0x00f41868 CoreImage_CIContext_FromOptions_CoreImage_CIContextOptions + 48
Basically, some logic in CIContext.FromOptions causes it to crash.
For now, I have made cicontext object a static variable that is initialized just once. This seems to take care of the crash. However, I would appreciate it if you have any insight. Regards.

Answer 1

For those running into this problem, this fix worked for us:
Call cicontext = CIContext.FromOptions(null) just once and hold on to the return value, either as a member variable or a static variable.
After calling CreateCGImage call cicontext.ClearCaches(). If this is not done, you will eventually run out of memory.
Hope this helps. Regards.