What are some examples of deadlocks in Python?

What are some examples of deadlocks in Python?

Deadlocks occur when two or more threads are blocked forever, each waiting on the other. A common example in Python is when two threads hold locks and each tries to acquire the lock held by the other.

Can you show me a code example of a deadlock?

Sure! Here's a simple example:

import threading
import time

lock1 = threading.Lock()
lock2 = threading.Lock()

def thread1():
    lock1.acquire()
    time.sleep(1)
    lock2.acquire()
    print("Thread 1 finished")
    lock2.release()
    lock1.release()


def thread2():
    lock2.acquire()
    time.sleep(1)
    lock1.acquire()
    print("Thread 2 finished")
    lock1.release()
    lock2.release()

thread_a = threading.Thread(target=thread1)
thread_b = threading.Thread(target=thread2)

thread_a.start()
thread_b.start()

thread_a.join()
thread_b.join()

What can I do to avoid deadlocks?

To avoid deadlocks, you can use techniques like lock ordering, timeouts, or using higher-level abstractions like threading.Condition or threading.Semaphore.

Are there any libraries that help manage deadlocks?

Yes, libraries like concurrent.futures and asyncio can help manage concurrency and reduce the risk of deadlocks by providing higher-level abstractions.