[oe] Simultaneous build of two intree packages

[Radek Dostal]

Dear All,

I have three intree recipes A, B and C which are part of the same layer.
=> B depends on A
=> C depends on A.

There is no dependency between B and C. Only important thing is that B
and C are not build simultaneously. This is not a problem unless I use
configure BB_NUMBER_THREADS > 1. Than builds B and C starts to collide
and produce mess because they are both intree builds.

Is there something like a mutex/lock mechanism in openembedded-core,
which would forbid two recipes to be build simultaneously?

Thanks,
Radek