Fix WatchService modification detection with fixed timestamps - #510
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YuqiGuo105 wants to merge 2 commits into
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YuqiGuo105 wants to merge 2 commits into
YuqiGuo105 wants to merge 2 commits into
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YuqiGuo105
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August 21, 2026 17:52
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Summary
FileTimeSourceProblem
PollingWatchServicecurrently compares onlylastModifiedTimevalues. If a file is written while the configured clock returns the same timestamp (for example, a fixed or low-resolution clock), the content changes but noENTRY_MODIFYevent is emitted.The new snapshot state uses the file ID and its modification version. This detects writes without reading or hashing file contents, while also distinguishing a same-name replacement file.
Testing
mvn -pl jimfs -Dtest=PollingWatchServiceTest,FileTest testmvn test(5,906 tests passed, 1 skipped)Fixes #483