[WIP] Deadlock when creating typed HttpClient with DI and HttpClientFactory #40740
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- with DI and HttpClientFactory
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Tagging subscribers to this area: @maryamariyan |
tarekgh
reviewed
Aug 12, 2020
| @@ -91,6 +92,7 @@ internal class DefaultHttpClientFactory : IHttpClientFactory, IHttpMessageHandle | |||
| } | |||
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| _services = services; | |||
| _builder = _services.GetRequiredService<HttpMessageHandlerBuilder>(); | |||
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does this will introduce any new memory allocations?
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I should have created this as a draft PR. I'll add NO MERGE label instead. |
maryamariyan
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maryamariyan
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Closing PR. There's more calls to GetRequiredServices crossing the code path expressed in the issue that might cause a problem: https://github.com/dotnet/aspnetcore/blob/master/src/Middleware/HeaderPropagation/src/DependencyInjection/HeaderPropagationHttpClientBuilderExtensions.cs#L32 |
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Fixes: #35986
Perhaps a more general fix would be to correct the DI limitation for when a singleton instantiation required a transient that is to be lazily instantiated.
I am assuming here in order to just fix HttpClientFactory issue, that it is OK to get HttpMessageHandlerBuilder first hand in the constructor and whenever we want to lazily call CreateHandlerEntry, then the builder is already available (we basically move the GetRequiredService call out of lazy block to fix the deadlock.)
Then perhaps in 6.0 we could look to also fix the DI limitation that causes us to use this workaround.
cc: @davidfowl @tarekgh @eerhardt