[OE-core] [PATCH 1/1] sstate.bbclass: fix parallel building issue

[Richard Purdie]

On Thu, 2013-08-15 at 11:27 -0500, Mark Hatle wrote:
> On 8/15/13 11:23 AM, Richard Purdie wrote:
> > On Thu, 2013-08-15 at 10:55 +0100, Phil Blundell wrote:
> >> On Thu, 2013-08-15 at 17:51 +0800, Rongqing Li wrote:
> >>> OK, But your issue is not related to me.
> >>>
> >>> I can reproduce my issue by two simple script.
> >>
> >> If tar is deciding that the file has "changed" just because the link
> >> count on the dentry has increased, that sounds like it is probably a bug
> >> in tar and ought to be fixed there.
> >>
> >> That said, I can't immediately think why autotools_copy_aclocal couldn't
> >> use a symlink rather than a hard link which would avoid this whole
> >> problem.  If the file is in the sysroot then there should be no risk of
> >> it going away underneath its user.
> >
> > Sadly this doesn't work. We block copy a set of .m4 files from the
> > sysroot. We can be running do_configure of package A whilst package B is
> > de-installed from the sysroot and this leads to files disappearing
> > whilst they're being accessed. Its turned out to be a really awkward
> > problem to fix.
> 
> Do we need some kind of a read/write lock on accessing those files.  (Is this 
> even something that we can do easily though the existing mechanisms?)

It would kill performance for no good reason, been there, looked at
it...

Cheers,

Richard