What interaction methods are used to ensure data consistency in multithreaded applications?

To ensure data consistency in multithreaded applications on iOS, the following main interaction methods are used:

• Synchronization via GCD (Grand Central Dispatch): allows executing tasks in specific queues (serial or concurrent), helping to avoid simultaneous access to shared resources.

• Use of locks: for example, NSLock, pthread_mutex to protect critical sections of code.

• Operations with operation queues (NSOperationQueue): enable managing dependencies and the sequence of task execution.

• Atomic properties: in Objective-C, properties can be declared as atomic to ensure thread-safe access.

• Use of thread-safe data structures or creating custom synchronization mechanisms.

Example with GCD:

let serialQueue = DispatchQueue(label: "com.example.serialQueue")

serialQueue.sync {
    // Code that will be executed sequentially,
    // preventing data races
}

Thus, proper use of queues and locks helps to avoid data consistency issues.