ios crash EXC_BAD_ACCESS KERN_INVALID_ADDRESS

Question

MyApp works well 98% of the time, but sometimes it crashes. It\'s so random.

The crash report shows the following.

Thread : Crashed: com.apple.main-thr         


        

Answer 1

EXC_BAD_ACCESS KERN_INVALID_ADDRESS crash is not due to memory leak, but due to the attempt to access an deallocated object.

Example: if you used __weak typeof(self) weakSelf = self; and object has been released before you accessing it inside block you'll got the crash. The reason — access to wrong memory address because object was deallocated.

To prevent this use __strong typeof(self) strongSelf = self; inside the block. Nil value will be properly handled without crash

---

Note: use this code sample for fast work.

#define weakify(var) __weak typeof(var) AHKWeak_##var = var;

#define strongify(var) \
_Pragma("clang diagnostic push") \
_Pragma("clang diagnostic ignored \"-Wshadow\"") \
__strong typeof(var) var = AHKWeak_##var; \
_Pragma("clang diagnostic pop")

Usage example:

weakify(self); // Remove retain cycle
[self someFunctionWithBlock:^{
    strongify(self); // Make reference to address valid

}];