is it thread safe to assign a new value to a static object in c#

Question

Taking the following code, what happens in a multithreaded environment:

static Dictionary<string,string> _events = new Dictionary<string,string>();

public static Dictionary<string,string> Events { get { return _events;} }

public static void ResetDictionary()
{
    _events = new Dictionary<string,string>();
}

In a multithreaded environment this method and property can be accessed in the same time by different threads.

Is it thread safe to assign a new object to a static variable that is accessible in different threads? What can go wrong ?

Is there a moment in time when Events can be null ?? If 2 threads call in the same time Events and ResetDictionary() for example.

Answer 1

Is it thread safe to assign a new object to a static variable that is accessible in different threads?

Basically, yes. In the sense that the property will never be invalid or null.

What can go wrong ?

A reading thread can continue to use the old dictionary after another thread has reset it. How bad this is depends entirely on your program logic and requirements.