Inherits from NSMutableDictionary
Declared in SNThreadSafeDictionary.h

SNThreadSafeDictionary.m

A simple implementation of thread safe mutable dictionary.Generally, access performance is lower than NSMutableDictionary, but higher than using @synchronized, NSLock, or pthread_mutex_t.It’s also compatible with the custom methods in NSDictionary(YYAdd) and NSMutableDictionary(YYAdd)source code from YYKit

Warning: Fast enumerate(for...in) and enumerator is not thread safe, use enumerate using block instead. When enumerate or sort with block/callback, do NOT send message to the dictionary inside the block/callback.