Mis on primitiivide eesmärk ja kasutamine mitmetuumalistes rakendustes niitide sünkroniseerimiseks?

Synchronization primitives in multithreaded applications are used to coordinate access to shared resources and prevent race conditions.

Main tasks:

• Ensure mutual exclusion (mutex) — so that only one thread can work with the critical section at a time.
• Synchronize the execution order of threads (semaphores, condition variables).
• Ensure the atomicity of operations.

In iOS (Objective-C/Swift), commonly used are:

• NSLock — a simple mutex.
• DispatchSemaphore — a semaphore to limit the number of threads executing simultaneously.
• @synchronized (Objective-C) — syntactic sugar for mutex.
• DispatchQueue — for sequential execution of tasks.

Example of using NSLock:

let lock = NSLock()

func criticalSection() {
    lock.lock()
    // work with shared resource
    lock.unlock()
}

Thus, synchronization primitives help prevent errors related to parallel access and ensure the correct operation of multithreaded applications.