c# synchronisation How lock behaves

Question

I have question regarding threading in c#.See the code posted below.

 public class TestThreading
{
    private System.Object lockThis = new System.Object();

    public void Function1()
    {

        lock (lockThis)
        {
            // Access thread-sensitive resources.
        }
    }

    public void Function2(){
        lock (lockThis)
        {
            // Access thread-sensitive resources.
        }

    }

}

Now my question is if some thread entered in Function1 (inside lock block) and at the same time another thread enters in Function2 what will happen

1. The threads will execute independently.
2. The thread which entered in Function 2 Goes to waits until lock is released by Funtion1 thread.
3. The thread which entered in Function 2 throws exception.

I am new to c# hence asking simple basic question. Thanks in advance.

Answer 1

The thread which entered in Function 2 Goes to waits until lock is released by Funtion1 thread.

The purpose of the lock is just that: provide a "safe" region of code that can be accessed only by one thread at a time. The other thread will be put to sleep, and resumed when the first one releases the lock.