> On Aug 12, 2025, at 4:07 PM, Thomas Munro <[email protected]> wrote: > > On Mon, Aug 11, 2025 at 10:56 AM Tom Lane <[email protected]> wrote: >> A bit more research later: OpenBSD behaves like NetBSD, while >> FreeBSD behaves like Linux. So that's pretty inconclusive about >> what the aboriginal behavior was. I also found that OpenIndiana >> behaves like Linux. > > Out of curiosity, FreeBSD changed that in 2016: > > https://github.com/freebsd/freebsd-src/commit/f00fb5457ebf5907055e420d803ac67fb098109e
I believe that this is the code in macOS's "XNU" [1][2] which has similar logic (unsurprisingly) to the FreeBSD code before the identified commit [3]. best. -greg [1] https://github.com/apple-oss-distributions/xnu/blob/e3723e1f17661b24996789d8afc084c0c3303b26/bsd/kern/sysv_sem.c#L860-L889 [2] "XNU is a hybrid kernel combining the Mach kernel developed at Carnegie Mellon University with components from FreeBSD and a C++ API for writing drivers called IOKit." [3] https://github.com/freebsd/freebsd-src/commit/f00fb5457ebf5907055e420d803ac67fb098109e
