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Port of the Zephyr RTOS zbus (many-to-many message bus with typed channels and decoupled observers), built entirely on native NuttX primitives and preserving the original declarative API (ZBUS_CHAN_DEFINE, ZBUS_LISTENER_DEFINE, ZBUS_SUBSCRIBER_DEFINE, ...). Features: listeners (synchronous callbacks), subscribers (queue of channel references), message subscribers (ordered message copies), async listeners (callback on a dedicated task), runtime observers, per-observation notification masks, observer enable/disable, message validators, channel user data, publish statistics, lookup by name/numeric id and channel/observer iteration. Mapping to NuttX primitives: - Channel/observer registration: link-time iterable sections (include/nuttx/iterable_sections.h); the observers of a channel are named after their position in the definition, so the linker sorts the notification order, and the declarative macros are built on nuttx/macro.h (CONCATENATE, FOREACH_ARG and the FOREACH_IDX_ARG added in a companion nuttx commit) rather than on a private macro engine. Notification masks live in .bss with their initial value preserved in ROM and applied on lazy init. - Channel lock: sem_t (enable CONFIG_PRIORITY_INHERITANCE instead of the Zephyr priority-boost/HLP); timeouts are computed with the clock_timespec_* helpers from nuttx/clock.h. - Subscriber queues: kernel message queues (file_mq_*) opened lazily via pthread_once, usable from any task; mq payload copying replaces the Zephyr net_buf machinery entirely. - Async listeners: one task per listener (task_create, priority and stack size configurable) blocking on the listener queue; a task rather than a pthread so it outlives the first API caller. - Timeouts: milliseconds with CLOCK_MONOTONIC deadlines (ZBUS_NO_WAIT/ZBUS_FOREVER). Includes a runnable example (examples/zbus, CONFIG_EXAMPLES_ZBUS) and a cmocka test suite (testing/zbus, CONFIG_TESTING_ZBUS) covering the full API: 17/17 tests passing on linum-stm32h753bi hardware, including multi-channel index grouping, mask semantics, runtime observer error paths, notification order (the observers of a channel run in the order they are listed, and an observation bound with ZBUS_CHAN_ADD_OBS() runs after all of them), queue overflow/timeout semantics, async listener bursts, bit-exact float/double payload delivery across every observer type (sensor-style messages with a float-math validator) and an interrupt-driven publisher (kernel timer interrupt -> signal -> sampling thread -> zbus_chan_pub, the recommended pattern for interrupt sources). Requirements: FLAT build; CONFIG_MQ_MAXMSGSIZE >= pointer size + CONFIG_ZBUS_MSG_SUBSCRIBER_MAX_MSG_SIZE for message subscribers; board linker script including <nuttx/linker/common-rom.ld> or the generic CONFIG_ITERABLE_SECTIONS_LINKER_INSERT mode. Not ported: multi-domain proxy agent (experimental upstream); publishing from interrupt handlers (userspace library: hand the data to a thread). Documentation lives in the nuttx repository (Documentation/applications/system/zbus). Assisted-by: Claude Code Signed-off-by: Jorge Guzman <jorge.gzm@gmail.com> |
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| .. | ||
| CMakeLists.txt | ||
| Kconfig | ||
| Make.defs | ||
| Makefile | ||
| zbus.c | ||
| zbus_iterable_sections.c | ||
| zbus_priv.h | ||
| zbus_runtime_observers.c | ||