What are some examples of deadlock in code?

What are some examples of deadlock in code?

Deadlock occurs when two or more threads are blocked forever, each waiting on the other. A classic example is when Thread A holds Resource 1 and waits for Resource 2, while Thread B holds Resource 2 and waits for Resource 1.

Can you give me a code snippet that demonstrates this?

Sure! Here's a simple example in Python:

import threading

resource1 = threading.Lock()
resource2 = threading.Lock()

def thread_a():
    with resource1:
        print('Thread A acquired Resource 1')
        with resource2:
            print('Thread A acquired Resource 2')

def thread_b():
    with resource2:
        print('Thread B acquired Resource 2')
        with resource1:
            print('Thread B acquired Resource 1')

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

thread1.start()
thread2.start()

thread1.join()
thread2.join()

What can be done to prevent deadlocks?

To prevent deadlocks, you can use techniques like resource ordering, timeout mechanisms, or implementing a deadlock detection algorithm.

Are there any tools to help detect deadlocks?

Yes, there are several tools available, such as VisualVM for Java applications, and Thread Sanitizer for C/C++ programs, which can help detect deadlocks during development.