Logger

Universal logger module with deferred processing. More...

Data Structures
struct	logger
	Logger instance. More...

Macros
#define	LOGGER_MAX_ARGC   6
	The maximum number of logger_put() arguments supported by the implementation. More...
#define	LOGGER_INIT(log, log_write_cb, log_capacity, str_capacity)
	Initializes the logger instance and allocates its string and FIFO buffers. More...
#define	LOGGER_PUT(log, ...)    logger_put(log, VA_ARGC(__VA_ARGS__), __VA_ARGS__)
	Logs a message. More...

Functions
bool	logger_init (struct logger *log)
	Initializes logger. More...
bool	logger_put (const struct logger *log, int argc, const char *fmt,...)
	Logs a message (puts it into internal buffer for later processing). More...
bool	logger_process (const struct logger *log)
	Processes a single logged message from the buffer. More...

Detailed Description

Universal logger module with deferred processing.

Macro Definition Documentation

LOGGER_MAX_ARGC

#define LOGGER_MAX_ARGC   6

The maximum number of logger_put() arguments supported by the implementation.

It is possible to reduce the number by providing a custom LOGGER_MAX_ARGC definition to save the space required by logger_entry.

LOGGER_INIT

#define LOGGER_INIT	(		log,
			log_write_cb,
			log_capacity,
			str_capacity
	)

Value:

        do { \
                static struct fifo logger_fifo; \
                FIFO_INIT(&logger_fifo, sizeof(struct logger_entry), \
                         (log_capacity)); \
                static char str[(str_capacity)]; \
                (log)->fifo = &logger_fifo; \
                (log)->write_cb = (log_write_cb); \
                (log)->str = (str); \
                (log)->str_size = (str_capacity); \
                (log)->write_cb = (log_write_cb); \
                logger_init((log)); \
        } while (0)

Initializes the logger instance and allocates its string and FIFO buffers.

Parameters

log	Pointer to the logger structure
log_write_cb	Pointer to write callback implemented by driver (see logger.write_cb for details)
log_capacity	Capacity of the internal FIFO (maximum number of messages to be stored, see fifo.capacity)
str_capacity	Capacity of the internal string buffer (should be large enough to store a message composed by snprintf, see logger.str and logger.str_size)

LOGGER_PUT

#define LOGGER_PUT	(		log,
			...
	)		logger_put(log, VA_ARGC(__VA_ARGS__), __VA_ARGS__)

Logs a message.

This is a macro which automatically determines the number of arguments and is replaced by the proper function logger_put0() to logger_put6().

Parameters

log	Pointer to the logger structure
...	Format string and up to LOGGER_MAX_ARGC optional arguments to be passed to sprintf (the format string is mandatory).

Function Documentation

logger_init()

bool logger_init

(

struct logger *

log

)

Initializes logger.

Parameters

log	Pointer to the logger structure

Returns

true if initialization succeeds, false otherwise

logger_put()

bool logger_put	(	const struct logger *	log,
		int	argc,
		const char *	fmt,
			...
	)

Logs a message (puts it into internal buffer for later processing).

The message consists of a format string and variable number of arguments which will be processed by sprintf in logger_process(). To determine the number of arguments (argc) automatically, use macro LOGGER_PUT() instead.

The access to internal fifo is protected by a critical section so logger_put() can be called from multiple threads or interrupt handlers.

Parameters

	log	Pointer to the logger structure
	argc	Number of arguments (0 to LOGGER_MAX_ARGC)
[in]	fmt	Format string to be passed to sprintf
	...	Optional arguments to be passed to sprintf (only argc parameters will be processed)

Returns

true if initialization succeeds, false otherwise (internal FIFO is full)

logger_process()

bool logger_process

(

const struct logger *

log

)

Processes a single logged message from the buffer.

This function calls logger.write_cb callback (implemented by the driver) to write the message to an actual output interface. It is meant to defer log processing from high priority contexts (such as interrupts) and should be therefore called in a low-priority context (e.g. a main loop).

It is assumed this function is called from multiple threads (the internal fifo is not protected by any locking mechanism).

Parameters

log	Pointer to the logger structure

Returns

true if a message has been processed, false otherwise (internal FIFO is empty)