How is information exchange between execution threads carried out in software applications?

Communication between execution threads in software applications is usually carried out through:

• Shared variables and data structures — using synchronization mechanisms (mutexes, semaphores, locks) to avoid data races.
• Message queues — threads place messages into a queue, and other threads read them.
• Events and signals — to notify threads about certain states.

In Python, for example, queue.Queue is often used for data exchange between threads, which is thread-safe:

import threading
import queue

q = queue.Queue()

def producer():
    q.put('data')

def consumer():
    data = q.get()
    print(data)

threading.Thread(target=producer).start()
threading.Thread(target=consumer).start()