Is it necessary to use synchronization when executing coroutines launched in the Main Dispatcher to safely increase a shared variable?

If coroutines are launched in the Main Dispatcher (i.e., in the main thread), synchronization for increasing a shared variable is usually not required because the code executes sequentially in a single thread.

However, if the variable can be modified from other threads or dispatchers, synchronization is necessary to prevent data races.

Example of safely increasing a variable in the Main Dispatcher:

var counter = 0

fun increment() {
    // Runs in Main Dispatcher, so synchronization is not needed
    counter++
}

If access to the variable occurs from different threads, it is advisable to use Mutex or atomic types.