Is Objective-C's NSMutableArray thread-safe?

Question

I\'ve been trying to fix this crash for almost a week. The application crashes without any exception or stack-trace. The application does not crash in any way while running

Answer 1

All the NSMutablexxx classes are not thread-safe. Operations including get,insert,remove,add and replace should be used with NSLock.This is a list of thread-safe and thread-unsafe classes given by apple: Thread Safety Summary