In the forked child, we may use multiprocessing. There is only one event pipe to the worker controlling process and if we're unlucky, multiple processes can write to it at once corrupting the data by intermixing it. We don't see this often but when we do, its quite puzzling. I suspect it only happens in tasks which use multiprocessng (do_rootfs, do_package) and is much more likely to happen when we have long messages, usually many times PAGE_SIZE since PAGE_SIZE writes are atomic. This makes it much more likely within do_roofs, when for example a subprocess lists the contents of a rootfs. To fix this, we give each child a Lock() object and use this to serialise writes to the controlling worker. (Bitbake rev: 3cb55bdf06148943960e438291f9a562857340a3) Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Poky
Poky is an integration of various components to form a complete prepackaged build system and development environment. It features support for building customised embedded device style images. There are reference demo images featuring a X11/Matchbox/GTK themed UI called Sato. The system supports cross-architecture application development using QEMU emulation and a standalone toolchain and SDK with IDE integration.
Additional information on the specifics of hardware that Poky supports is available in README.hardware. Further hardware support can easily be added in the form of layers which extend the systems capabilities in a modular way.
As an integration layer Poky consists of several upstream projects such as BitBake, OpenEmbedded-Core, Yocto documentation and various sources of information e.g. for the hardware support. Poky is in turn a component of the Yocto Project.
The Yocto Project has extensive documentation about the system including a reference manual which can be found at: http://yoctoproject.org/documentation
OpenEmbedded-Core is a layer containing the core metadata for current versions of OpenEmbedded. It is distro-less (can build a functional image with DISTRO = "nodistro") and contains only emulated machine support.
For information about OpenEmbedded, see the OpenEmbedded website: http://www.openembedded.org/
Where to Send Patches
As Poky is an integration repository (built using a tool called combo-layer), patches against the various components should be sent to their respective upstreams:
bitbake: Git repository: http://git.openembedded.org/bitbake/ Mailing list: bitbake-devel@lists.openembedded.org
documentation: Git repository: http://git.yoctoproject.org/cgit/cgit.cgi/yocto-docs/ Mailing list: yocto@yoctoproject.org
meta-yocto(-bsp): Git repository: http://git.yoctoproject.org/cgit/cgit.cgi/meta-yocto(-bsp) Mailing list: poky@yoctoproject.org
Everything else should be sent to the OpenEmbedded Core mailing list. If in doubt, check the oe-core git repository for the content you intend to modify. Before sending, be sure the patches apply cleanly to the current oe-core git repository.
Git repository: http://git.openembedded.org/openembedded-core/
Mailing list: openembedded-core@lists.openembedded.org
Note: The scripts directory should be treated with extra care as it is a mix of oe-core and poky-specific files.