Add IConcurrentPolicyRegistry interface/implementation, for PolicyRegistry

Why IPolicyRegistry does not have TryAdd() method?

I am seeing KeyAlreadyExistiError when I run this code in multi-threaded test. This is due to multiple requests are trying to add policy at the same time - registry.Add(“TimeoutPolicy”,, retryTimeoutPolicy);

            IPolicyRegistry<string> registry = sp.GetRequiredService<IPolicyRegistry<string>>();
            IAsyncPolicy<HttpResponseMessage> policy = null;
            registry.TryGet<IAsyncPolicy<HttpResponseMessage>>(“TimeoutPolicy”, out policy);
            if (policy == null)
            {
                policy = Policy
                    .TimeoutAsync<HttpResponseMessage>(TimeSpan.FromMilliseconds(10000));

                registry.Add(“TimeoutPolicy”,policy);
            }

            return policy;

I fixed this issue by replacing .Add with this code - registry[“TimeoutPolicy”] = policy; What is the recommended way in this scenario?

This could have solved if we have TryAdd method like ConcurrentDictionary. Why IPolicyRegistry does not have TryAdd() method?

[aerotog]

Reviewing PolicyRegistry, it’s already a facade for ConcurrentDictionary, so I think adding a new interface dedicated to concurrent methods seems redundant. Especially since the pattern of including Try methods in the Policy interfaces already exists with TryGet being defined in IReadOnlyPolicyRegistry.

ConcurrentDictionary has a number of methods that don’t seem useful/relevant to this ticket. Based on the existing methods in PolicyRegistry (including TryGet), I’ve added:

• TryAdd
• TryRemove

These have been committed. Once I’ve added tests for these (probably this weekend), I’ll open a PR.

[shagilt]

@reisenberger yes, this code is an existing code(before new extension method available in HttpClientFactory). I will have to change our code to use the new extension method.