Repository: dotnet/efcore
File: src/EFCore/Internal/ServiceProviderCache.cs (C#)

Code before:
        foreach (var extension in options.Extensions)
        {
            extension.ApplyServices(services);

            if (extension.Info.IsDatabaseProvider)
            {
                coreServicesAdded = true;
            }
        }

        if (coreServicesAdded)
        {
            return true;
        }

        new EntityFrameworkServicesBuilder(services).TryAddCoreServices();

        return false;
    }

    /// <summary>
    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
    ///     any release. You should only use it directly in your code with extreme caution and knowing that
    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
    /// </summary>
    public virtual void Clear() => _configurations.Clear();
}


Review comment (performance):
The Clear() method calls Clear() on a ConcurrentDictionary (_configurations) which can cause issues if other threads are accessing the cache concurrently. While ConcurrentDictionary.Clear() is thread-safe, clearing the cache while it's being used by other contexts can lead to unexpected behavior. Consider documenting this concurrency concern in the XML documentation comment, warning users that this method should only be called when no DbContexts are actively being created or used, typically in test cleanup scenarios.
```suggestion
    /// </summary>
    /// <remarks>
    ///     This method clears the internal cache of service providers. While the underlying data structure is thread-safe,
    ///     clearing the cache while other threads are creating or using <see cref="DbContext" /> instances can lead to
    ///     unexpected behavior. It should only be called when no contexts are actively being created or used, typically in
    ///     test cleanup scenarios.
    /// </remarks>
```

Code after:
        foreach (var extension in options.Extensions)
        {
            extension.ApplyServices(services);

            if (extension.Info.IsDatabaseProvider)
            {
                coreServicesAdded = true;
            }
        }

        if (coreServicesAdded)
        {
            return true;
        }

        new EntityFrameworkServicesBuilder(services).TryAddCoreServices();

        return false;
    }

    /// <summary>
    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
    ///     any release. You should only use it directly in your code with extreme caution and knowing that
    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
    /// </summary>
    /// <remarks>
    ///     This method clears the internal cache of service providers. While the underlying data structure is thread-safe,
    ///     clearing the cache while other threads are creating or using <see cref="DbContext" /> instances can lead to
    ///     unexpected behavior. It should only be called when no contexts are actively being created or used, typically in
    ///     test cleanup scenarios.
    /// </remarks>
    public virtual void Clear() => _configurations.Clear();
}