Bug 21627 – macOS: std.stdio.File.sync does not guarantee to be written to disk

The documentation(https://dlang.org/phobos/std_stdio.html#.File.sync) says: > Forces any data buffered by the OS to be written to disk. > Call flush before calling this function to flush the C FILE buffers first. Accoriding to macOS's manapge, however, fsync(2) does not guarantee to be written to disk. https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/fsync.2.html > Note that while fsync() will flush all data from the host to the drive > (i.e. the "permanent storage device"), the drive itself may not physically > write the data to the platters for quite some time and it may be > written in an out-of-order sequence. > > Specifically, if the drive loses power or the OS crashes, the application > may find that only some or none of their data was written. The disk > drive may also re-order the data so that later writes may be present, > while earlier writes are not. > > This is not a theoretical edge case. This scenario is easily reproduced > with real world workloads and drive power failures. The manpage also says that the F_FULLFSYNC fcntl would be useful in this case. > For applications that require tighter guarantees about the integrity of > their data, Mac OS X provides the F_FULLFSYNC fcntl. The F_FULLFSYNC > fcntl asks the drive to flush all buffered data to permanent storage. I think std.stdio.File.sync should use F_FULLSYNC fcntl.

@kubo39 created dlang/phobos pull request #7789 "Fix Issue 21627 - macOS: std.stdio.File.sync does not guarantee to be…" fixing this issue: - Fix Issue 21627 - macOS: std.stdio.File.sync does not guarantee to be written to disk https://github.com/dlang/phobos/pull/7789

dlang/phobos pull request #7789 "Fix Issue 21627 - macOS: std.stdio.File.sync does not guarantee to be…" was merged into master: - f0f199066e1a7ce2451edf5813f2bf0b9ed5dc40 by Hiroki Noda: Fix Issue 21627 - macOS: std.stdio.File.sync does not guarantee to be written to disk https://github.com/dlang/phobos/pull/7789