Reduce lock usage during EditDistance.GetEditDistance and BKTree.Find#75610
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ToddGrun merged 2 commits intodotnet:mainfrom Oct 24, 2024
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The SimplePool and ArrayPool classes previously used always locked on Allocate/Free which is showing up in a trace David Kean referred us to. Instead, as the char arrays being allocated are typically quite small, utilize the stack for these temporary char array locations when possible, falling back to heap allocating in the rare occasions where it's not.
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Oct 24, 2024
| lowerCaseCharacters[i] = CaseInsensitiveComparison.ToLower(value[i]); | ||
| Span<char> lowerCaseCharacters = value.Length < 512 | ||
| ? stackalloc char[value.Length] | ||
| : new char[value.Length]; |
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I would still use the pool for large strings.
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Just here, or in EditDistance too? I'm not sure about here, but I wouldn't think the EditDistance code would almost ever exceed 512 chars.
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Just to make sure, I don't think the old code was pooling large strings, as ArrayPool checked against MaxPooledArraySize for both retrieving and returning from the pool.
This was referenced Oct 29, 2024
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The SimplePool and ArrayPool classes previously always locked on Allocate/Free which is showing up in a cpu usage in a trace David Kean referred to us. Instead, as the char arrays being allocated are typically quite small, utilize the stack for these temporary char array locations when possible, falling back to heap allocating in the extremely rare occasions where it's not.
Below is the cpu usage that David pointed us to:
