Is it possible for multiple sources to read the same object simultaneously?

Yes, multiple sources (such as threads or processes) can read the same object simultaneously in iOS. Reading data is usually a side-effect-free operation and does not require locks if the object is not being modified. However, if the object can be modified, synchronization must be ensured to avoid race conditions and to obtain consistent data. Mechanisms such as GCD, NSLock, or atomic operations are used for this purpose.