c# - Threading behavior of methods of a class object declared as static member of another class -

recently colleague of mine came piece of code , asked opinion regarding thread safety of code. below example illustrates same scenario code.

public class classa {    public int doworka()     {         //some logic     } }  public class classb {      public static classa obja = new classa(); }  public class classc {         int doworkc ()          {             return classb.obja.doworka();          } } 

now if classb.obja.doworka() called simulatenously in different instances of different classes classc, classd etc there threading or 'overlap' issues ? should obja converted instance member ?

since obja static there single instance of classa. means threads access method doworka() on same instance, not mean method call thread-safe - entirely depends on implementation of doworka().

you still need appropriate logic in doworka protect problems can arise concurrent access, e.g. use of locking or thread-safe collections etc.