What is nonatomic ?

Question

hello friends Can you explain What is nonatomic in iphone

Chintan Rathod · Answer

Hi Sachin Basically if you say nonatomic and you generate the accessors using @synthesize then if multiple threads try to change/read the property at once badness can happen. You can get partially-written values or over-released/retained objects which can easily lead to crashes. (This is potentially a lot faster than an atomic accessor though.) If you use the default (which is atomic; there's no keyword for this) then the @synthesized methods use an object-level lock to ensure that multiple reads/writes to a property are serialized. As the Apple docs point out this doesn't mean the whole object is thread-safe but the property reads/writes are. Of course if you implement your own accessors rather than using @synthesize I think these declarations do nothing except express your intent as to whether the property is implemented in a threadsafe manner. Reference: Apple Docs Thanks