Re: Enabling hi-res timestamps on Windows

On Wed, Feb 19, 2025 at 7:41 AM Eli Zaretskii <[email protected]> wrote:
>
> > Date: Tue, 18 Feb 2025 22:06:11 +0100 (GMT+01:00)
> > From: Eldred HABERT <[email protected]>
> >
> > Hello!
> >
> > I am having an issue that some versions of Make never stop on a Make file I made, but only on Windows.
> > https://github.com/ISSOtm/gb-starter-kit/issues/1#issuecomment-1793775226
> > I have traced the issue to hi-res timestamps being disabled for some builds of Make; apparently, those that use `config.h.W32`, which explicitly disables hi-res timestamps. The MSYS2 port was reported to work reliably.
> >
> > Thus: I'd like to request that hi-res timestamps be enabled in that config file.
>
> It is not that simple.  GNU Make uses 'stat' to retrieve the time
> stamp of files, and the Windows implementation of 'stat' reports times
> without hi-res data.  So to define FILE_TIMESTAMP_HI_RES in the native
> Windows port of GNU Make, someone will need to produce a
> reimplementation of 'stat' that returns higher-resolution time stamp.
>
> Patches are welcome.
>
> (The MSYS2 port uses the Cygwin runtime library, whose 'stat' does
> provide hi-res times.  But the native port cannot use the Cygwin
> runtime, it must use the native runtime or the Win32 APIs.)

Another sharp edge is, the hi-res timer on Windows may appear to move
backwards in time as queries are made on different cores. Also see
<https://stackoverflow.com/q/44020619>.

Jeff