CA1840: Use Environment.CurrentManagedThreadId instead of Thread.CurrentThread.ManagedThreadId

#Cause

Using Thread.CurrentThread.ManagedThreadId for getting the current managed thread ID instead of System.Environment.CurrentManagedThreadId.

#Rule description

System.Environment.CurrentManagedThreadId is a compact and efficient replacement of the Thread.CurrentThread.ManagedThreadId pattern.

#How to fix violations

The violation can either be fixed manually, or, in some cases, using Quick Actions to fix code in Visual Studio.

The following two code snippets show a violation of the rule and how to fix it:

using System.Threading;

class MyClass
{
    void MyMethod()
    {
        int id = Thread.CurrentThread.ManagedThreadId; // Violation occurs
    }
}

Imports System.Threading

Class MyClass
    Private Sub MyMethod()
        Dim id As Integer = Thread.CurrentThread.ManagedThreadId ' Violation occurs.
    End Function
End Class

using System.Threading;

class MyClass
{
    void MyMethod()
    {
        int id = System.Environment.CurrentManagedThreadId; // Violation fixed
    }
}

Imports System.Threading

Class MyClass
    Private Sub MyMethod()
        Dim id As Integer = System.Environment.CurrentManagedThreadId ' Violation fixed.
    End Function
End Class

#When to suppress warnings

It's safe to suppress a violation of this rule if you're not concerned about the performance impact from using Thread.CurrentThread.ManagedThreadId.

#Suppress a warning

If you just want to suppress a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.

#pragma warning disable CA1840
// The code that's violating the rule is on this line.
#pragma warning restore CA1840

To disable the rule for a file, folder, or project, set its severity to none in the configuration file.

[*.{cs,vb}]
dotnet_diagnostic.CA1840.severity = none

For more information, see How to suppress code analysis warnings.

#See also

• Performance rules
• Use 'Environment.ProcessId' instead of 'Process.GetCurrentProcess().Id'
• Use 'Environment.ProcessPath' instead of 'Process.GetCurrentProcess().MainModule.FileName'