I have an object that contains a very large 3D-array of doubles and I need to start a new thread that need the data of this array, so I will either need to start a new threa
To be more precise it's send by reference copy.
Since this is a reference type, only a reference is copied in this case, and not all data.
reference type
That's why you have to care about locking mechanisms in cases where more then one thread accesses the data this object refers to.
locking mechanisms
thread