Is it possible to explain the concept of race conditions in a multithreaded environment and how it can affect program operation?

Race condition occurs when multiple threads access and modify shared data simultaneously without proper synchronization. As a result, the final data state can be unpredictable and depend on the execution order of threads.

For example, if two threads increment a counter at the same time without locks, the final value might be less than expected due to lost updates.

In iOS, race conditions can lead to crashes, incorrect UI display, or data corruption. To prevent this, synchronization mechanisms are used:

• GCD queues with serial attribute
• NSLock, @synchronized
• Atomic properties

Example with GCD:

let serialQueue = DispatchQueue(label: "com.example.serial")
var counter = 0

serialQueue.sync {
    counter += 1
}

This guarantees that changes to counter happen sequentially.