Comment by supermatt
4 years ago
> transferred to the storage device
MacOS does that.
> the fsync() function is intended to force a physical write of data from the buffer cache
If they define _POSIX_SYNCHRONIZED_IO, which they dont.
fsync wasnt defined as requiring a flush until version 5 of the spec. It was implemented in BSDs loooong before then. Apple introduced F_FULLFSYNC prior to fsync having that new definition.
I dont disagree with you, but it is what it is. History is a thing. Legacy support is a thing. Apple likely didnt want to change peoples expectations of the behaviour on OSX - they have their own implementation after all (which is well documented, lots of portable software and libs actively uses it, and its built in to the higher level APIs that Mac devs consume).
> > transferred to the storage device
> MacOS does that.
Depends on the definition of "storage device", I guess. If it's physical media, then OS X doesn't. If it's the controller, then OS X does. But since the intent is to have the data reach persistent storage, it has to be the physical media.
My guess is that since people know all of this, they'll just keep working around it as they already do. Newbies to OS X development will get bitten unless they know what to look for.