Logger backend interface

Logger backend interface . More...

Topics
	Logger multidomain backend helpers
	Logger multidomain backend helpers.

Data Structures
union	log_backend_evt_arg
	Argument(s) for backend events. More...
struct	log_backend_api
	Logger backend API. More...
struct	log_backend_control_block
	Logger backend control block. More...
struct	log_backend
	Logger backend structure. More...

Macros
#define	LOG_BACKEND_DEFINE(_name, _api, _autostart, ...)
	Macro for creating a logger backend instance.

Enumerations
enum	log_backend_evt { LOG_BACKEND_EVT_PROCESS_THREAD_DONE , LOG_BACKEND_EVT_MAX }
	Backend events. More...

Functions
static void	log_backend_init (const struct log_backend *const backend)
	Initialize or initiate the logging backend.
static int	log_backend_is_ready (const struct log_backend *const backend)
	Poll for backend readiness.
static void	log_backend_msg_process (const struct log_backend *const backend, union log_msg_generic *msg)
	Process message.
static void	log_backend_dropped (const struct log_backend *const backend, uint32_t cnt)
	Notify backend about dropped log messages.
static void	log_backend_panic (const struct log_backend *const backend)
	Reconfigure backend to panic mode.
static void	log_backend_id_set (const struct log_backend *const backend, uint8_t id)
	Set backend id.
static uint8_t	log_backend_id_get (const struct log_backend *const backend)
	Get backend id.
static const struct log_backend *	log_backend_get (uint32_t idx)
	Get backend.
static int	log_backend_count_get (void)
	Get number of backends.
static void	log_backend_activate (const struct log_backend *const backend, void *ctx)
	Activate backend.
static void	log_backend_deactivate (const struct log_backend *const backend)
	Deactivate backend.
static bool	log_backend_is_active (const struct log_backend *const backend)
	Check state of the backend.
static int	log_backend_format_set (const struct log_backend *backend, uint32_t log_type)
	Set logging format.
static void	log_backend_notify (const struct log_backend *const backend, enum log_backend_evt event, union log_backend_evt_arg *arg)
	Notify a backend of an event.

Detailed Description

Logger backend interface .

Macro Definition Documentation

LOG_BACKEND_DEFINE

#define LOG_BACKEND_DEFINE	(		_name,
			_api,
			_autostart,
			... )

#include <zephyr/logging/log_backend.h>

Value:

        static struct log_backend_control_block UTIL_CAT(backend_cb_, _name) = \
        {                                                                      \
                COND_CODE_0(NUM_VA_ARGS_LESS_1(_, ##__VA_ARGS__),              \
                                (), (.ctx = __VA_ARGS__,))                     \
                .id = 0,                                                       \
                .active = false,                                               \
        };                                                                     \
        static const STRUCT_SECTION_ITERABLE(log_backend, _name) =             \
        {                                                                      \
                .api = &_api,                                                  \
                .cb = &UTIL_CAT(backend_cb_, _name),                           \
                .name = STRINGIFY(_name),                                      \
                .autostart = _autostart                                        \
        }

Macro for creating a logger backend instance.

Parameters

_name	Name of the backend instance.
_api	Logger backend API.
_autostart	If true backend is initialized and activated together with the logger subsystem.
...	Optional context.

Enumeration Type Documentation

log_backend_evt

enum log_backend_evt

#include <zephyr/logging/log_backend.h>

Backend events.

Enumerator
LOG_BACKEND_EVT_PROCESS_THREAD_DONE	Event when process thread finishes processing. This event is emitted when the process thread finishes processing pending log messages. Note This is not emitted when there are no pending log messages being processed. Deferred mode only.
LOG_BACKEND_EVT_MAX	Maximum number of backend events.

Function Documentation

log_backend_activate()

static void log_backend_activate ( const struct log_backend *const backend, void * ctx )

inlinestatic

#include <zephyr/logging/log_backend.h>

Activate backend.

Parameters

[in]	backend	Pointer to the backend instance.
[in]	ctx	User context.

log_backend_count_get()

static int log_backend_count_get ( void )

inlinestatic

#include <zephyr/logging/log_backend.h>

Get number of backends.

Returns

Number of backends.

log_backend_deactivate()

static void log_backend_deactivate ( const struct log_backend *const backend )

inlinestatic

#include <zephyr/logging/log_backend.h>

Deactivate backend.

Parameters

[in]

backend

Pointer to the backend instance.

log_backend_dropped()

static void log_backend_dropped ( const struct log_backend *const backend, uint32_t cnt )

inlinestatic

#include <zephyr/logging/log_backend.h>

Notify backend about dropped log messages.

Function is optional.

Parameters

[in]	backend	Pointer to the backend instance.
[in]	cnt	Number of dropped logs since last notification.

log_backend_format_set()

static int log_backend_format_set ( const struct log_backend * backend, uint32_t log_type )

inlinestatic

#include <zephyr/logging/log_backend.h>

Set logging format.

Parameters

backend	Pointer to the backend instance.
log_type	Log format.

Return values

-ENOTSUP	If the backend does not support changing format types.
-EINVAL	If the input is invalid.
0	for success.

log_backend_get()

static const struct log_backend * log_backend_get ( uint32_t idx )

inlinestatic

#include <zephyr/logging/log_backend.h>

Get backend.

Parameters

[in]

idx

Pointer to the backend instance.

Returns

Pointer to the backend instance.

log_backend_id_get()

static uint8_t log_backend_id_get ( const struct log_backend *const backend )

inlinestatic

#include <zephyr/logging/log_backend.h>

Get backend id.

Note

It is used internally by the logger.

Parameters

[in]

backend

Pointer to the backend instance.

Returns

Id.

log_backend_id_set()

static void log_backend_id_set ( const struct log_backend *const backend, uint8_t id )

inlinestatic

#include <zephyr/logging/log_backend.h>

Set backend id.

Note

It is used internally by the logger.

Parameters

backend	Pointer to the backend instance.
id	ID.

log_backend_init()

static void log_backend_init ( const struct log_backend *const backend )

inlinestatic

#include <zephyr/logging/log_backend.h>

Initialize or initiate the logging backend.

If backend initialization takes longer time it could block logging thread if backend is autostarted. That is because all backends are initialized in the context of the logging thread. In that case, backend shall provide function for polling for readiness (log_backend_is_ready).

Parameters

[in]

backend

Pointer to the backend instance.

log_backend_is_active()

static bool log_backend_is_active ( const struct log_backend *const backend )

inlinestatic

#include <zephyr/logging/log_backend.h>

Check state of the backend.

Parameters

[in]

backend

Pointer to the backend instance.

Returns

True if backend is active, false otherwise.

log_backend_is_ready()

static int log_backend_is_ready ( const struct log_backend *const backend )

inlinestatic

#include <zephyr/logging/log_backend.h>

Poll for backend readiness.

If backend is ready immediately after initialization then backend may not provide this function.

Parameters

[in]

backend

Pointer to the backend instance.

Return values

0	if backend is ready.
-EBUSY	if backend is not yet ready.

log_backend_msg_process()

static void log_backend_msg_process ( const struct log_backend *const backend, union log_msg_generic * msg )

inlinestatic

#include <zephyr/logging/log_backend.h>

Process message.

Function is used in deferred and immediate mode. On return, message content is processed by the backend and memory can be freed.

Parameters

[in]	backend	Pointer to the backend instance.
[in]	msg	Pointer to message with log entry.

log_backend_notify()

static void log_backend_notify ( const struct log_backend *const backend, enum log_backend_evt event, union log_backend_evt_arg * arg )

inlinestatic

#include <zephyr/logging/log_backend.h>

Notify a backend of an event.

Parameters

backend	Pointer to the backend instance.
event	Event to be notified.
arg	Pointer to the argument(s).

log_backend_panic()

static void log_backend_panic ( const struct log_backend *const backend )

inlinestatic

#include <zephyr/logging/log_backend.h>

Reconfigure backend to panic mode.

Parameters

[in]

backend

Pointer to the backend instance.