This rule raises an issue each time a `static` field is updated from a non-static method or property.

== Why is this an issue?

Updating a `static` field from a non-`static` method introduces ignificant challenges and potential bugs. Multiple class instances and threads can access and modify the `static` field concurrently, leading to unintended consequences for other instances or threads (unexpected behavior, https://www.c-sharpcorner.com/UploadFile/1d42da/race-conditions-in-threading-C-Sharp/[race conditions] and synchronization problems).

[source,csharp]
----
class MyClass 
{
  private static int count = 0;

  public void DoSomething() 
  {
    //...
    count++;  // Noncompliant: make the enclosing instance property 'static' or remove this set on the 'static' field.
  }
}

interface MyInterface
{
  private static int count = 0;

  public void DoSomething() 
  {
    //...
    count++;  // Noncompliant: remove this set, which updates a 'static' field from an instance method.
  }
}
----

== Resources

=== Documentation

* https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/static-classes-and-static-class-members[Static Classes and Static Class Members]
* https://learn.microsoft.com/en-us/dotnet/standard/threading/using-threads-and-threading[Using threads and threading]

=== Articles & blog posts

* https://www.c-sharpcorner.com/UploadFile/1d42da/race-conditions-in-threading-C-Sharp/[Race Conditions in C#]

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

* Make the enclosing instance [method|property] "static" or remove this set on the "static" field.
* Remove this set, which updates a "static" field from an instance [method|property].

=== Highlighting

Primary: static field assignment

Secondary: static field declaration

'''
== Comments And Links
(visible only on this page)

=== on 24 Jun 2015, 07:03:57 Tamas Vajk wrote:
\[~ann.campbell.2] I've created this subtask, because in C# this rule can also apply for properties. Furthermore, the `synchronized static` part doesn't work for C#.

=== on 24 Jun 2015, 14:01:07 Ann Campbell wrote:
looks good [~tamas.vajk]

include::../comments-and-links.adoc[]

endif::env-github,rspecator-view[]