Thread-safe Enumerator without Deadlock

Question

Hey, i need a way in C# to do a really long Enumeration without Deadlocking the program, at the moment i have a List which it enumerates through doing GetEnumerator() on it and using While(e.MoveNext) etc. But it deadlocks i also have it locking the same list when it needs to add stuff to it.
How can i write a thread-safe enumerator without causing locking?

Sam Hobbs · Answer

I don't what else to say but I hope the additional clarification you have provided will help someone else to help you.

Matthew Southall · Answer

At the moment it locks the list while it enumerates, and it also locks the list when adding and removing from it. The problem is it is deadlocking in the Enumerator and im not sure what can cause this, is it possible to deadlock if theres an error in the code used to enumerate through? Im looking for a way of making it enumerate through properly, and release the lock when finished. It seems to deadlock at random times too could be minutes or hours. I don't know c# that well and certainly don't know enumerating well but i can't find any way to get it to work properly with locking at a certain time. What other information do you need? let me know if any.

Sam Hobbs · Answer

I think there is much more that needs to be specified. What do you mean by deadlock? What is causing it? Do you need for the list to be accessed by multiple threads? What kind of access? Do you need to be able to add to the list while a different thread is enumerating? If so, then you must decide what to do in that situation. Without answers to those questions, it seems obvious to me that you simply want to prevent a thread from using the list when anoher thread is using it. If that is not possible then you must explain what your requirements are that make it not a reasonalbe solution.