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43b8002b14
This commit adds the newlib retargetable locking interface function implementations in order to make newlib functions thread safe. The newlib retargetable locking interface is internally called by the standard C library functions provided by newlib to synchronise access to the internal shared resources. By default, the retargetable locking interface functions defined within the newlib library are no-op. When multi-threading is enabled (i.e. `CONFIG_MULTITHREADING=y`), the Zephyr-side retargetable locking interface implementations override the default newlib implementation and provide locking mechanism. The retargetable locking interface may be called with either a static (`__lock__...`) or a dynamic lock. The static locks are statically allocated and initialised immediately after kernel initialisation by `newlib_locks_prepare`. The dynamic locks are allocated and de-allocated through the `__retargetable_lock_init[_recursive]` and `__retarget_lock_close_[recurisve]` functions as necessary by the newlib functions. These locks are allocated in the newlib heap using the `malloc` function when userspace is not enabled -- this is safe because the internal multi-threaded malloc lock implementations (`__malloc_lock` and `__malloc_unlock`) call the retargetable locking interface with a static lock (`__lock__malloc_recursive_mutex`). When userspace is enabled, the dynamic locks are allocated and freed through `k_object_alloc` and `k_object_release`. Note that the lock implementations used here are `k_mutex` and `k_sem` instead of `sys_mutex` and `sys_sem` because the Zephyr kernel does not currently support dynamic allocation of the latter. These locks should be updated to use `sys_mutex` and `sys_sem` when the Zephyr becomes capable of dynamically allocating them in the future. Signed-off-by: Stephanos Ioannidis <root@stephanos.io> |
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| .buildkite | ||
| .github | ||
| arch | ||
| boards | ||
| cmake | ||
| doc | ||
| drivers | ||
| dts | ||
| include | ||
| kernel | ||
| lib | ||
| misc | ||
| modules | ||
| samples | ||
| scripts | ||
| share | ||
| soc | ||
| subsys | ||
| tests | ||
| .checkpatch.conf | ||
| .clang-format | ||
| .codecov.yml | ||
| .editorconfig | ||
| .gitattributes | ||
| .gitignore | ||
| .gitlint | ||
| .mailmap | ||
| .uncrustify.cfg | ||
| CMakeLists.txt | ||
| CODE_OF_CONDUCT.md | ||
| CODEOWNERS | ||
| CONTRIBUTING.rst | ||
| Kconfig | ||
| Kconfig.zephyr | ||
| LICENSE | ||
| MAINTAINERS.yml | ||
| README.rst | ||
| VERSION | ||
| version.h.in | ||
| west.yml | ||
| zephyr-env.cmd | ||
| zephyr-env.sh | ||
.. raw:: html
<a href="https://www.zephyrproject.org">
<p align="center">
<img src="doc/_static/images/logo-readme.png">
</p>
</a>
<a href="https://bestpractices.coreinfrastructure.org/projects/74"><img
src="https://bestpractices.coreinfrastructure.org/projects/74/badge"></a>
<a href="https://buildkite.com/zephyr/zephyr">
<img
src="https://badge.buildkite.com/f5bd0dc88306cee17c9b38e78d11bb74a6291e3f40e7d13f31.svg?branch=main"></a>
The Zephyr Project is a scalable real-time operating system (RTOS) supporting
multiple hardware architectures, optimized for resource constrained devices,
and built with security in mind.
The Zephyr OS is based on a small-footprint kernel designed for use on
resource-constrained systems: from simple embedded environmental sensors and
LED wearables to sophisticated smart watches and IoT wireless gateways.
The Zephyr kernel supports multiple architectures, including ARM Cortex-M,
Intel x86, ARC, Nios II, Tensilica Xtensa, and RISC-V, and a large number of
`supported boards`_.
.. below included in doc/introduction/introduction.rst
Getting Started
***************
Welcome to Zephyr! See the `Introduction to Zephyr`_ for a high-level overview,
and the documentation's `Getting Started Guide`_ to start developing.
.. start_include_here
Community Support
*****************
Community support is provided via mailing lists and Slack; see the Resources
below for details.
.. _project-resources:
Resources
*********
Here's a quick summary of resources to help you find your way around:
* **Help**: `Asking for Help Tips`_
* **Documentation**: http://docs.zephyrproject.org (`Getting Started Guide`_)
* **Source Code**: https://github.com/zephyrproject-rtos/zephyr is the main
repository; https://elixir.bootlin.com/zephyr/latest/source contains a
searchable index
* **Releases**: https://github.com/zephyrproject-rtos/zephyr/releases
* **Samples and example code**: see `Sample and Demo Code Examples`_
* **Mailing Lists**: users@lists.zephyrproject.org and
devel@lists.zephyrproject.org are the main user and developer mailing lists,
respectively. You can join the developer's list and search its archives at
`Zephyr Development mailing list`_. The other `Zephyr mailing list
subgroups`_ have their own archives and sign-up pages.
* **Nightly CI Build Status**: https://lists.zephyrproject.org/g/builds
The builds@lists.zephyrproject.org mailing list archives the CI
(buildkite) nightly build results.
* **Chat**: Zephyr's Slack workspace is https://zephyrproject.slack.com. Use
this `Slack Invite`_ to register.
* **Contributing**: see the `Contribution Guide`_
* **Wiki**: `Zephyr GitHub wiki`_
* **Issues**: https://github.com/zephyrproject-rtos/zephyr/issues
* **Security Issues**: Email vulnerabilities@zephyrproject.org to report
security issues; also see our `Security`_ documentation. Security issues are
tracked separately at https://zephyrprojectsec.atlassian.net.
* **Zephyr Project Website**: https://zephyrproject.org
.. _Slack Invite: https://tinyurl.com/2vue8666
.. _supported boards: http://docs.zephyrproject.org/latest/boards/index.html
.. _Zephyr Documentation: http://docs.zephyrproject.org
.. _Introduction to Zephyr: http://docs.zephyrproject.org/latest/introduction/index.html
.. _Getting Started Guide: http://docs.zephyrproject.org/latest/getting_started/index.html
.. _Contribution Guide: http://docs.zephyrproject.org/latest/contribute/index.html
.. _Zephyr GitHub wiki: https://github.com/zephyrproject-rtos/zephyr/wiki
.. _Zephyr Development mailing list: https://lists.zephyrproject.org/g/devel
.. _Zephyr mailing list subgroups: https://lists.zephyrproject.org/g/main/subgroups
.. _Sample and Demo Code Examples: http://docs.zephyrproject.org/latest/samples/index.html
.. _Security: http://docs.zephyrproject.org/latest/security/index.html
.. _Asking for Help Tips: https://docs.zephyrproject.org/latest/getting_started/index.html#asking-for-help