@Will,

“finally” isn’t a critical section by itself. In general, you can have two threads executing the finally block of the same method at the same time. However, “lock” uses “try” and “finally” under the hood.

The following piece of code:

lock(orange)
{
DoSomething();
}

… is munged by the compiler to IL achieving the following:

Monitor.Enter(orange);
try
{
DoSomething();
}
finally
{
Monitor.Exit(orange);
}

So you are right in that, the “finally” generated by the compiler when it sees “lock” is a critical section because of the Monitor.Enter call that preceded it. But I’m not sure if you were thinking that deep “finally” isn’t a critical section on its own.

As for other alternatives to “lock”, one could use any of Monitor, Mutex or Semaphore to implement critical sections. Not sure if you were referring to them.

This is also an example why you need to be VERY careful of what you do in a finally block. If you get into a race condition within one, good luck recovering.