Why use SyncLocks in .NET for simple operations when Interlocked class is available?

Question

I've been doing simple multi-threading in VB.NET for a while, and have just gotten into my first large multi-threaded project. I've always done everything using the Synclock statement because I didn't think there was a better way.

I just learned about the Interlocked Class - it makes it look as though all this:

Private SomeInt as Integer
Private SomeInt_LockObject as New Object

Public Sub IntrementSomeInt
    Synclock SomeInt_LockObject
        SomeInt += 1
    End Synclock
End Sub

Can be replaced with a single statement:

Interlocked.Increment(SomeInt)

This handles all the locking internally and modifies the number. This would be much simpler than writing my own locks for simple operations (longer-running or more complicated operations obviously still need their own locking).

Is there a reason why I'd rolling my own locking, using dedicated locking objects, when I can accomplish the same thing using the Interlocked methods?

Answer 1

You're correct; Interlocked should be used here, and will be faster than SyncLock.
However, the Interlocked class is not well-known.

However, there are situations where you need to use SyncLock and Interlocked will not help.