multithreading - C# threading deadlock

Question

I have a multi-threaded program in C#. What is the best way to prevent deadlock in practice?

Is it timedlock?

Also, what is the best tool available to help detect and prevent the deadlock?

Thank you very much.

Answer 1

Deadlocks typically occur in a few scenarios:

1. You are using several locks and not locking/unlocking them in the correct order. Hence, you may create a situation where a thread holds lock A and needs lock B, and another thread needs lock A and holds lock B. Neither of them can proceed. This is because each thread is locking in a different order.

2. When using a reentrant lock and locking it more times than you are unlocking it. See this related question: why does the following code result in deadlock

3. When using Monitor.Wait/Monitor.Pulse as a signaling mechanism, but the thread that must call Wait does not manage to reach the call by the time the other thread has called Pulse and the signal is lost. You can use the AutoResetEvent for a persistent signal.

4. You have a worker thread polling a flag to know when to stop. The main thread sets the flag and attempts to join the worker thread, but you forgot to make the flag volatile.