MultithreadingSynchronization.swift

import Foundation

var count = 0
let group = DispatchGroup()

group.enter()
let thread1 = Thread {
    for _ in 0...9999 {
        count += 1
    }
    group.leave()
}

group.enter()
let thread2 = Thread {
    for _ in 0...9999 {
        count += 1
    }
    group.leave()
}

thread1.start()
thread2.start()

group.notify(queue: DispatchQueue.global()) {
    print(count)
}