Backends

Outputs of log messages. More...

Data Structures
struct	pbl_log_msg
	Log message. More...
struct	pbl_log_backend_api
	Backend operations. More...
struct	pbl_log_backend_state
	Runtime state of a backend. More...
struct	pbl_log_backend
	Backend. More...

Macros
#define	PBL_LOG_MSG_ASYNC   (1U << 0)
	The message may be written after pbl_log_backend_api::process returns.
#define	PBL_LOG_MSG_FAULT   (1U << 1)
	The message comes from a fault handler, where OS services are unavailable.
#define	PBL_LOG_BACKEND_DEFINE(_name, _api, _level, _autostart)
	Define a backend.
#define	PBL_LOG_BACKEND_GET(_name)
	Get a backend defined with PBL_LOG_BACKEND_DEFINE.

Functions
void	pbl_log_backend_enable (const struct pbl_log_backend *backend)
	Start passing messages to backend.
void	pbl_log_backend_disable (const struct pbl_log_backend *backend)
	Stop passing messages to backend.
bool	pbl_log_backend_is_enabled (const struct pbl_log_backend *backend)
	Whether messages are passed to backend.
void	pbl_log_backend_set_level (const struct pbl_log_backend *backend, int level)
	Set the highest LOG_LEVEL_* level written by backend.
const struct pbl_log_backend *	pbl_log_backend_get_by_name (const char *name)
	Find a backend by name.
void	pbl_log_init (void)
	Initialize the backends.
void	pbl_log_panic (void)
	Have every backend write out its pending messages, the system is about to stop.

Detailed Description

Outputs of log messages.

A backend is defined with PBL_LOG_BACKEND_DEFINE and receives every message at or below its level through pbl_log_backend_api::process, in the context of the caller. The logging core only knows backends through this interface.

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Data Structure Documentation

pbl_log_msg

struct pbl_log_msg

Log message.

Data Fields
const uint8_t *	app_uuid	UUID of the app that logged the message, or NULL for system messages.
const char *	file	Source file name.
uint8_t	flags	PBL_LOG_MSG_* flags.
uint8_t	level	LOG_LEVEL_* level.
uint16_t	line	Source line number.
const char *	text	Message text, NUL-terminated.
uint8_t	text_len	Length of text in the binary log message format.
uint32_t	timestamp	Time the message was logged at, in seconds, or 0 if unknown.

pbl_log_backend_state

struct pbl_log_backend_state

Runtime state of a backend.

Data Fields
bool	enabled	Whether messages are passed to the backend.
int16_t	level	Highest LOG_LEVEL_* level written.

pbl_log_backend

struct pbl_log_backend

Backend.

Data Fields
const struct pbl_log_backend_api *	api	Operations.
const char *	name	Name.
struct pbl_log_backend_state *	state	Runtime state.

Macro Definition Documentation

PBL_LOG_BACKEND_DEFINE

#define PBL_LOG_BACKEND_DEFINE	(		_name,
			_api,
			_level,
			_autostart
	)

Value:

  static struct pbl_log_backend_state _pbl_log_backend_state_##_name = {        \
    .level = (_level),                                                          \
    .enabled = (_autostart)                                                     \
  };                                                                            \
  const struct pbl_log_backend _pbl_log_backend_##_name PBL_USED PBL_ALIGNED(4) \
      PBL_SECTION(".pbl_log_backends." #_name) = {                              \
        .name = #_name,                                                         \
        .api = &(_api),                                                         \
        .state = &_pbl_log_backend_state_##_name,                               \
  }

Define a backend.

Parameters

_name	Backend name, also its identifier.
_api	Backend operations.
_level	Initial highest LOG_LEVEL_* level written.
_autostart	Whether the backend starts enabled, or waits for pbl_log_backend_enable.

PBL_LOG_BACKEND_GET

#define PBL_LOG_BACKEND_GET

(

_name

)

Value:

  ({                                                              \
    extern const struct pbl_log_backend _pbl_log_backend_##_name; \
    &_pbl_log_backend_##_name;                                    \
  })

Get a backend defined with PBL_LOG_BACKEND_DEFINE.

Parameters

_name

Backend name.

PBL_LOG_MSG_ASYNC

#define PBL_LOG_MSG_ASYNC   (1U << 0)

The message may be written after pbl_log_backend_api::process returns.

PBL_LOG_MSG_FAULT

#define PBL_LOG_MSG_FAULT   (1U << 1)

The message comes from a fault handler, where OS services are unavailable.

Function Documentation

pbl_log_backend_disable()

void pbl_log_backend_disable

(

const struct pbl_log_backend *

backend

)

Stop passing messages to backend.

pbl_log_backend_enable()

void pbl_log_backend_enable

(

const struct pbl_log_backend *

backend

)

Start passing messages to backend.

pbl_log_backend_get_by_name()

const struct pbl_log_backend * pbl_log_backend_get_by_name

(

const char *

name

)

Find a backend by name.

Returns

The backend, or NULL if there is none called name.

pbl_log_backend_is_enabled()

bool pbl_log_backend_is_enabled

(

const struct pbl_log_backend *

backend

)

Whether messages are passed to backend.

pbl_log_backend_set_level()

void pbl_log_backend_set_level	(	const struct pbl_log_backend *	backend,
		int	level
	)

Set the highest LOG_LEVEL_* level written by backend.

pbl_log_init()

void pbl_log_init

(

void

)

Initialize the backends.

pbl_log_panic()

void pbl_log_panic

(

void

)

Have every backend write out its pending messages, the system is about to stop.