Fix volatile correctness in lazy load and add roundtrip test#1747
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ken-swyfft wants to merge 2 commits intonissl-lab:masterfrom
Open
Fix volatile correctness in lazy load and add roundtrip test#1747ken-swyfft wants to merge 2 commits intonissl-lab:masterfrom
ken-swyfft wants to merge 2 commits intonissl-lab:masterfrom
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- Add volatile to _worksheetLoaded for correct double-checked locking on ARM/.NET platforms where memory ordering is weaker than x86 - Add SaveWithoutAccessPreservesUntouchedSheets test verifying that opening a workbook, modifying one sheet, and saving preserves untouched sheets' data through the lazy load Commit() early-return Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
…s/20260321_lazy-load-volatile-and-roundtrip-test
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Summary
Follow-up to #1741 (Sheet Lazy Loading):
Add
volatileto_worksheetLoaded— The double-checked locking pattern inEnsureWorksheetLoaded()reads_worksheetLoadedoutside the lock. Withoutvolatile, on ARM platforms (.NET on Apple Silicon, Graviton, etc.) the CPU's weaker memory ordering could allow a thread to see_worksheetLoaded = truebefore theworksheetfields are fully initialized. On x86/x64 this is a no-op due to strong ordering, so no perf impact.Add
SaveWithoutAccessPreservesUntouchedSheetstest — Creates a 3-sheet workbook, re-opens it, modifies only sheet 1, saves, and verifies sheets 0 and 2 survived the roundtrip with original data intact. This exercises thePrepareForCommit()andCommit()early-return paths that skip re-serialization of unaccessed sheets — the core value proposition of lazy loading.Test plan
TestXSSFSheetLazyLoadtests pass on both net8.0 and net472🤖 Generated with Claude Code