Usage of Mutex in c#

Question

I am a bit new in threading in c# and on general, in my program I am using mutex to allow only 1 thread getting inside a critical section and f

Answer 1

This pattern does no locking at all. Every thread creates a new Mutex object and immediately owns the lock for it. Other threads create and use a new Mutex itself.

Consider using a regular lock()!

lock(_lockobject) {
   // do inside what needs to be done - executed on a single thread only
} 

where _lockobject is a simple private variable in your class:

private object _lockobject; 

Edit: thanks to the commenters! Situations exist, where lock(this) can be dangerous. So I removed that.