Basic spinlock implementation is based on single
atomic variable and doesn't guarantee locking fairness
across multiple CPUs. It's even possible that single CPU
will win the contention every time which will result
in a live-lock.
Ticket spinlocks provide a FIFO order of lock aquisition
which resolves such unfairness issue at the cost of slightly
increased memory footprint.
Signed-off-by: Alexander Razinkov <alexander.razinkov@syntacore.com>
Currently spinlock internals are directly accessed from the tests.
This way the test becomes bound to the particular spinlock implementation.
To remove this unnecessary dependency the distinct API to check if spinlock
is locked is introduced.
k_spin_is_locked should be used for the spinlock testing only,
so the scope of this API is intentionally restricted.
Signed-off-by: Alexander Razinkov <alexander.razinkov@syntacore.com>
In function z_spin_onexit, when CONFIG_FORCE_NO_ASSERT=y
and CONFIG_SPIN_VALIDATE=y the function parameter becomes unused.
This generates a build error (unused parameter 'k').
Add __maybe_unused to fix this error.
Signed-off-by: Prashanth S <slpp95prashanth@yahoo.com>
Adds an assertion for the GCC toolchain to check whether the K_SPINLOCK
block was left without unlocking the spinlock, e.g. by calling break,
return or goto.
Signed-off-by: Florian Grandel <fgrandel@code-for-humans.de>
While the LOCKED pattern is universally useful it can be misused. This
change therefore exposes the LOCKED pattern with extensive usage
documentation to reduce the risk of abuse or unintended deadlock.
Signed-off-by: Florian Grandel <fgrandel@code-for-humans.de>
To satisfy the requirements of POSIX spinlocks, we need a common
way to attempt to lock a spinlock that will return an error if
unsuccessful.
Signed-off-by: Christopher Friedt <cfriedt@meta.com>
Give architectures that need it the ability to perform special checks
while e.g. waiting for a spinlock to become available.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
This commit updates all in-tree code to use `CONFIG_CPP` instead of
`CONFIG_CPLUSPLUS`, which is now deprecated.
Signed-off-by: Stephanos Ioannidis <stephanos.ioannidis@nordicsemi.no>
Move runtime code to use arch_num_cpus() instead of CONFIG_MP_NUM_CPUS
and use CONFIG_MP_MAX_NUM_CPUS for ifdef and BUILD_ASSERT macros.
Signed-off-by: Kumar Gala <kumar.gala@intel.com>
Spin locks held for any lengthy duration prevent interrupts and
in a real time system where interrupts drive tasks this can be
problematic. Add an option to assert if a spin lock is held for
a duration longer than the configurable number of microseconds.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
In order to bring consistency in-tree, migrate all includes within
include directory to the new prefix <zephyr/...>. Note that the
conversion has been scripted, refer to zephyrproject-rtos#45388 for more
details.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
Move include paths and add new target_include_directories to support
backwards compatibility:
* /include -> /include/zephyr
example: <irq.h> -> <zephyr/irq.h>
Issue #41543
Signed-off-by: Yuval Peress <peress@google.com>
