Re: [PATCH] dpkg.bbclass: add lockfile for do_build

[Henning Schild <henning.schild@siemens.com>]

Am Thu, 11 Jan 2018 13:31:45 +0300
schrieb Alexander Smirnov <asmirnov@ilbers.de>:

> Hello Christopher,
> 
> thank you for this catch!
> 
> On 01/10/2018 07:04 PM, Christopher Larson wrote:
> > All recipes using this class will run build.sh in the same chroot,
> > and build.sh runs apt-get to install deps, so the build can fail
> > due to dpkg being unable to acquire its lock. Add a bitbake
> > lockfile to ensure that only one do_build task for recipes
> > inheriting this class runs at a time. 
> 
> Serialization of do_build tasks leads to whole Isar serialization,
> what is significant issue if you have lots of packages to build. So I
> think the "build" and "deps installation" should be split in separate
> tasks and only the second one should be protected by locks.

The fact that Isar uses multiconfig to build many targets from the same
tree is not intuitive, we discussed this before. So i am not surprised
new contributors get that "wrong". Alex i suggest you split the task
and adopt Christophers changes.

Christopher, have a look at scripts/ci_build.sh and you will see that
Isar is capable of building multiple images at once in the same tree.
If you are building 10 images you will have 10 buildchroots that have
to be serialized seperately. A feature that probably nobody but the
CI-bot will ever use ;).

Henning

> Alex
> 
> > Signed-off-by: Christopher Larson <kergoth@gmail.com>
> > ---
> >   meta/classes/dpkg.bbclass | 1 +
> >   1 file changed, 1 insertion(+)
> > 
> > diff --git a/meta/classes/dpkg.bbclass b/meta/classes/dpkg.bbclass
> > index c10f5ba..3966a71 100644
> > --- a/meta/classes/dpkg.bbclass
> > +++ b/meta/classes/dpkg.bbclass
> > @@ -7,3 +7,4 @@ inherit dpkg-base
> >   dpkg_runbuild() {
> >       sudo chroot ${BUILDCHROOT_DIR} /build.sh ${PP}/${SRC_DIR}
> >   }
> > +do_build[lockfiles] += "${TMPDIR}/dpkg.lock"
> >  
>