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CA2015: Do not define finalizers for types derived from MemoryManager<T>

  • Article
Property Value
Rule ID CA2015
Title Do not define finalizers for types derived from MemoryManager<T>
Category Reliability
Fix is breaking or non-breaking Non-breaking
Enabled by default in .NET 9 As warning

Cause

Defining finalizers for types derived from MemoryManager<T>

Rule description

Adding a finalizer to a type derived from MemoryManager<T> is likely an indication of a bug, as it suggests a native resource that could have been handed out in a Span<T> is getting cleaned up and potentially while it is still in use by the Span<T>.

Note

The MemoryManager<T> class is intended for advanced scenarios. Most developers do not need to use it.

How to fix violations

To fix the violation, remove the finalizer definition.

class DerivedClass <T> : MemoryManager<T>
{
    public override bool Dispose(bool disposing)
    {
        if (disposing)
        {
            _handle.Dispose();
        }
    }

    ...

    // Violation occurs, remove the finalizer to fix the warning.
    ~DerivedClass() => Dispose(false);
}

When to suppress warnings

It is safe to suppress a violation of this rule if the intent is to create a finalizer for debugging or validation purposes.

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 CA2015
// The code that's violating the rule is on this line.
#pragma warning restore CA2015

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

[*.{cs,vb}]
dotnet_diagnostic.CA2015.severity = none

To disable this entire category of rules, set the severity for the category to none in the configuration file.

[*.{cs,vb}]
dotnet_analyzer_diagnostic.category-Reliability.severity = none

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

See also