Avoid using ConcurrentDictionary for channels with few methods #2597
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src/Grpc.Net.Client/Internal/ThreadSafeLookup.cs:24
- The comment should be corrected to 'Looking up a key in an array is as fast as a dictionary for small collections and uses much less memory.'
// Looking up a key in an array is as fast as a dictionary for small collections and uses much less memory.
gfoidl
reviewed
Feb 17, 2025
Co-authored-by: Günther Foidl <gue@korporal.at>
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@BrennanConroy Good feedback. I don't think the type would have broken and caused errors, but it could have gotten into a weird state (using the dictionary but still having some values in the array, duplicate values in the array). I've placed all updates in the lock. And added a comment about the value that's created. @gfoidl The main goal here is to optimize idle memory usage. Making the array only as big as it needs to be, plus some array allocations while a channel is first used is an ok tradeoff. |
gfoidl
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Feb 18, 2025
Co-authored-by: Günther Foidl <gue@korporal.at>
BrennanConroy
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Feb 18, 2025
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GrpcChannelhas aConcurrentDictionaryto cache method details. However, if the channel never has more than a handful of methods thenConcurrentDictionaryuses a large amount of memory to store just a few instances.This PR adds a
ThreadSafeLookuptype that uses a replacing array for a small number of items and upgrades to a dictionary beyond a threashold.