Set the right flags when Shared is selected.
#9130
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emillon
approved these changes
Nov 9, 2023
rgrinberg
approved these changes
Nov 9, 2023
`exclusive` selects between `LOCK_EX` and `LOCK_SH` but if it is `false` `LOCK_SH` is never set on the flags. This could've worked if `LOCK_SH` is `0` but at least on GNU/Linux on amd64 with glibc, `LOCK_SH` is `1`. We never use `Shared` in the Dune codebase but in case we would, it better works otherwise it would create issues that are hard to debug. Discovered by @emillon as we were investigating the semantics of write locks. Signed-off-by: Marek Kubica <marek@tarides.com>
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exclusiveselects betweenLOCK_EXandLOCK_SHbut if it isfalseLOCK_SHis never set on the flags. This could've worked ifLOCK_SHis0but at least on GNU/Linux on amd64 with glibc,LOCK_SHis1.We never use
Sharedin the Dune codebase but in case we would, it better works otherwise it would create issues that are hard to debug.Discovered by @emillon as we were investigating the semantics of write locks.