4de5c296db
The previous patches have exposed new issues with this code path,
the issues being around what should happen when the hash of a task
changes and the task is or is not on the deferred task list.
Rather than rebuilding the deferred task list during each rehash
event, build it once at the start of a build. This avoids the problem
of tasks being added back after they have run and also avoids problems
of always ensuring the same task is deferred. It also allows the
'outrightfail' codepath to be handled separately as the conditions
are subtly differnt.
One significant win for the new approch is the build is not continually
printing out lists of deferred tasks, that list remains fairly static
from the start of the build. Logic is added in to ensure a rehashed
task with a hash matching other deferred tasks is deferred along with
them as a small optimization.
An interesting test case for this code was reported by Mark Hatle
with four multiconfigs, each the same apart from TMPDIR and running a
build of:
bitbake buildtools-tarball mc:{one,two,three,four}:core-image-minimal
which is interesting in that the build of buildtools partially overlaps
core-image-minimal and the build has a rehash event for qemuwrapper-cross
even without any external hash equivalence server or preexisting data.
(Bitbake rev: 1775bcb95f61af21712bc1ba5098a49df8f21128)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit bb424e0a6d274d398f434f7df63951da9ce305b3)
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Bitbake
BitBake is a generic task execution engine that allows shell and Python tasks to be run efficiently and in parallel while working within complex inter-task dependency constraints. One of BitBake's main users, OpenEmbedded, takes this core and builds embedded Linux software stacks using a task-oriented approach.
For information about Bitbake, see the OpenEmbedded website: http://www.openembedded.org/
Bitbake plain documentation can be found under the doc directory or its integrated html version at the Yocto Project website: https://docs.yoctoproject.org
Contributing
Please refer to http://www.openembedded.org/wiki/How_to_submit_a_patch_to_OpenEmbedded for guidelines on how to submit patches, just note that the latter documentation is intended for OpenEmbedded (and its core) not bitbake patches (bitbake-devel@lists.openembedded.org) but in general main guidelines apply. Once the commit(s) have been created, the way to send the patch is through git-send-email. For example, to send the last commit (HEAD) on current branch, type:
git send-email -M -1 --to bitbake-devel@lists.openembedded.org
Mailing list:
http://lists.openembedded.org/mailman/listinfo/bitbake-devel
Source code:
http://git.openembedded.org/bitbake/