avoid Lock acquisition on ErrorCount/WarningCount when no errors exist#4157
Open
SimonCropp wants to merge 3 commits intodotnet:mainfrom
Open
Conversation
Contributor
SimonCropp
commented
Apr 8, 2026
SimonCropp
commented
- _hasErrorOrWarning marked volatile (line 278) -- the field was already read without a lock at line 1212, so this makes the existing pattern and the new fast paths correct across all memory models.
- ErrorCount fast path -- returns 0 immediately when _hasErrorOrWarning is false, skipping the lock. Safe because _hasErrorOrWarning is only set to false under the lock when _errors is also nulled.
- WarningCount fast path -- same treatment.
1. _hasErrorOrWarning marked volatile (line 278) -- the field was already read without a lock at line 1212, so this makes the existing pattern and the new fast paths correct across all memory models. 2. ErrorCount fast path -- returns 0 immediately when _hasErrorOrWarning is false, skipping the lock. Safe because _hasErrorOrWarning is only set to false under the lock when _errors is also nulled. 3. WarningCount fast path -- same treatment.
Contributor
There was a problem hiding this comment.
Pull request overview
This PR optimizes error/warning counting on TdsParserStateObject by adding a lock-free fast path when no errors/warnings are present, using a volatile flag to make the existing lock-free reads safe across memory models.
Changes:
- Mark
_hasErrorOrWarningasvolatileto support safe lock-free reads. - Add early-return fast paths in
ErrorCountandWarningCountwhen_hasErrorOrWarningisfalse.
src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs
Outdated
Show resolved
Hide resolved
src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs
Outdated
Show resolved
Hide resolved
…arserStateObject.cs Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
…arserStateObject.cs Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.