CA1837: Use Environment.ProcessId instead of Process.GetCurrentProcess().Id

Property	Value
Rule ID	CA1837
Title	Use Environment.ProcessId instead of Process.GetCurrentProcess().Id
Category	Performance
Fix is breaking or non-breaking	Non-breaking
Enabled by default in .NET 9	As suggestion

Cause

This rule locates calls to System.Diagnostics.Process.GetCurrentProcess().Id and suggests using System.Environment.ProcessId instead, because it is more efficient.

Rule description

System.Diagnostics.Process.GetCurrentProcess().Id is expensive:

• It allocates a Process instance, usually just to get the Id.
• The Process instance needs to be disposed, which has a performance impact.
• It's easy to forget to call Dispose() on the Process instance.
• If nothing else besides Id uses the Process instance, then the linked size grows unnecessarily by increasing the graph of types referenced.
• It is somewhat difficult to discover or find this API.

System.Environment.ProcessId avoids all the above.

Note

Rule CA1837 is available starting on .NET 5.0.

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.Diagnostics;

class MyClass
{
    void MyMethod()
    {
        int pid = Process.GetCurrentProcess().Id;
    }
}

Imports System.Diagnostics

Class MyClass
    Private Sub MyMethod()
        Dim pid As Integer = Process.GetCurrentProcess().Id
    End Function
End Class

using System.Diagnostics;

class MyClass
{
    void MyMethod()
    {
        int pid = System.Environment.ProcessId;
    }
}

Imports System.Diagnostics

Class MyClass
    Private Sub MyMethod()
        Dim pid As Integer = System.Environment.ProcessId
    End Function
End Class

Tip

A code fix is available for this rule in Visual Studio. To use it, position the cursor on the violation and press Ctrl+. (period). Choose Use 'Environment.ProcessId' instead of 'Process.GetCurrentProcess().Id' from the list of options that's presented.

When to suppress warnings

It's safe to suppress a violation of this rule if you're not concerned about the performance impact from unnecessary allocation and eventual disposal of a Process instance.

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 CA1837
// The code that's violating the rule is on this line.
#pragma warning restore CA1837

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

[*.{cs,vb}]
dotnet_diagnostic.CA1837.severity = none

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

See also

• Performance rules