[oe] Multiple bitbake and a shared DL_DIR location - race conditions?

[Richard Purdie]

On Sun, 2008-03-02 at 18:30 +0100, Leon Woestenberg wrote:
> in setting up a few automated builds, I have shared the DL_DIR amongst
> the builds.
> 
> I would like to allow the builds to overlap in time, at least make
> sure the builds are robust to this, but I doubt this is possible at
> all.
> 
> Are there any race conditions with the current approach?
> 
> I.e. what if two fetch tasks from concurrent instances of bitbake
> decide to download a package?

Each file in DL_DIR has a .lock file which bitbake has to acquire before
it will actually make the transfer. DL_DIR itself is therefore safe.

What might not be safe is the cvs/svn/git subdirs underneath this since
you could have two recipes trying to get different revisions of the same
repository which would go to different files in DL_DIR but use the same
scm directory. One solution is to override SVNDIR/GITDIR/CVSDIR.

Cheers,

Richard