For iterable areas defined with Z_STRUCT_SECTION_ITERABLE(),
the corresponding output section in the linker script is just
boilerplate. Add macros to make these definitions simpler.
Unfortunately, we have a fair number of iterable sections not
defined with Z_STRUCT_SECTION_ITERABLE(), this patch does not
address this.
The output sections are all named <struct name>_area, update
sanitylib.py with this.
sys_sem with no userspace, and k_lifo/k_fifo are special cases
where different data types that are all equivalent need to be
put in the same iterable area. Add
Z_STRUCT_SECTION_ITERABLE_ALTERNATE() for this special case.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Add a k_timeout_t type, and use it everywhere that kernel API
functions were accepting a millisecond timeout argument. Instead of
forcing milliseconds everywhere (which are often not integrally
representable as system ticks), do the conversion to ticks at the
point where the timeout is created. This avoids an extra unit
conversion in some application code, and allows us to express the
timeout in units other than milliseconds to achieve greater precision.
The existing K_MSEC() et. al. macros now return initializers for a
k_timeout_t.
The K_NO_WAIT and K_FOREVER constants have now become k_timeout_t
values, which means they cannot be operated on as integers.
Applications which have their own APIs that need to inspect these
vs. user-provided timeouts can now use a K_TIMEOUT_EQ() predicate to
test for equality.
Timer drivers, which receive an integer tick count in ther
z_clock_set_timeout() functions, now use the integer-valued
K_TICKS_FOREVER constant instead of K_FOREVER.
For the initial release, to preserve source compatibility, a
CONFIG_LEGACY_TIMEOUT_API kconfig is provided. When true, the
k_timeout_t will remain a compatible 32 bit value that will work with
any legacy Zephyr application.
Some subsystems present timeout (or timeout-like) values to their own
users as APIs that would re-use the kernel's own constants and
conventions. These will require some minor design work to adapt to
the new scheme (in most cases just using k_timeout_t directly in their
own API), and they have not been changed in this patch, instead
selecting CONFIG_LEGACY_TIMEOUT_API via kconfig. These subsystems
include: CAN Bus, the Microbit display driver, I2S, LoRa modem
drivers, the UART Async API, Video hardware drivers, the console
subsystem, and the network buffer abstraction.
k_sleep() now takes a k_timeout_t argument, with a k_msleep() variant
provided that works identically to the original API.
Most of the changes here are just type/configuration management and
documentation, but there are logic changes in mempool, where a loop
that used a timeout numerically has been reworked using a new
z_timeout_end_calc() predicate. Also in queue.c, a (when POLL was
enabled) a similar loop was needlessly used to try to retry the
k_poll() call after a spurious failure. But k_poll() does not fail
spuriously, so the loop was removed.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Commit db48d3e22a ("sys_sem: add build time definition macros")
recently introduced SYS_SEM_DEFINE() and defined it in terms of
Z_DECL_ALIGN() and __in_section() to force the _k_sem linker section.
It is however cleaner and less obscur to use Z_STRUCT_SECTION_ITERABLE()
and list the _sys_sem linker section alongside the _k_sem one.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
For systems with userspace, the sys_sem exist in user memory working
as counter semaphore for user mode thread. The implemention of sys_sem
is based on k_futex. And the majority of the synchronization operations
are performed in user mode to reduce the calling of system call.
And for systems without userspace enabled, sys_sem behaves like k_sem.
Fixes: #15139.
Signed-off-by: Wentong Wu <wentong.wu@intel.com>
