24 lines
1.2 KiB
Markdown
24 lines
1.2 KiB
Markdown
Plan is to be on vacation and/or low activity this week before DebConf.
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However, today I got involved in fixing a bug that caused the assistant to
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keep files open after syncing with repositories on removable media.
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Part of that bug involved lock files not being opend close-on-exec, and
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while fixing that I noticed again that the locking code was scattered all
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around and rather repetitive. That led to a lot of refactoring, which is
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always fun when it involves scary locking code. Thanks goodness for
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referential transparency.
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Now there's a Utility.LockFile that works on both POSIX and Windows.
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Howver, that module actually exports very different functions for the two.
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While it might be tempting to try to do a portability layer, the
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two locking models are really very different, and there are lots of gotchas
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such a portability layer would face. The only API that's completely the
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same between the two is dropLock.
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This refactoring process and the cleaner, more expressive
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code it led to helped me spot a couple of bugs involving locking. See
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[[!commit e386e26ef207db742da6d406183ab851571047ff]]
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and [[!commit 0a4d301051e4933661b7b0a0791afa95bfe9a1d3]]
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Neither bug has ever seemed to cause
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a problem, but it's nice to be able to spot and fix such bugs before they
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do.
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