List concurrent removing and adding

Question

I am not too sure, so i thought i\'d ask. Would removing and adding items to a System.Collections.Generic.List<> object be non-thread safe?

My sit

Answer 1

Actually, sometimes List<> is thread-safe, and sometimes not, according to Microsoft:

Public static members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

but that page goes on to say:

Enumerating through a collection is intrinsically not a thread-safe procedure. In the rare case where an enumeration contends with one or more write accesses, the only way to ensure thread safety is to lock the collection during the entire enumeration. To allow the collection to be accessed by multiple threads for reading and writing, you must implement your own synchronization.