Is it possible to make a piece of code atomic (C#)?

When I said atomic, I meant set of instructions will execute without any context switching to another thread on the same process (other kinds of switches have to be done of course). The only solution I came up with is to suspend all threads except currently executed before part and resume them after it. Any more elegant way?

The reason I want to do that is to co开发者_如何学Cllect a coherent state of objects running on multiple threads. However, their code cannot be changed (they're already compiled), so I cannot insert mutexes, semaphores, etc in it. The atomic operation is of course state collecting (i.e. copying some variables).

There are some atomic operations in the Interlocked class but it only provides a few very simple operations. It can't be used to create an entire atomic block of code.

I'd advise using locking carefully to make sure that your code will still work even if the context changes.

Well, you can use locks, but you can't prevent context switching exactly. But if your threads lock on the same object, then the threads waiting obviously won't be running, so there's no context switching involved since there's nothing to run.

You might want to look at this page too.

No. You can surround a block of code with a Monitor to make it thread-safe, but you cannot make general code snippets atomic.

object lck = new object();

lock(lck)
{
     // thread safe code goes in here

}

No, that's against multi-tasking.

Unless very simple operations like incrementing ... which are not subject of your question.

It is possible to obtain a global state from a shared memory composed of a collection (array) of atomic one reader/multi writer registers. The solution is simple but not trivial. You can read the algorithm published in the paper "atomic snapshots of shared memory" or you can read the chapter 4 from the art of multiprocesor programming book, there you can get ideas on the implementation on the java language, of course, once you are familiarized with the idea you should be able to transport it to any other language. Sorry if my english is not well enough.