elog.h File Reference

The fine-grained event logger allows lightweight, thread-safe event logging at minimum cost. More...

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Data Structures
struct	elog_event_t
struct	elog_event_type_t
struct	elog_track_t
struct	elog_time_stamp_t
struct	elog_main_t

Macros
#define	ELOG_TYPE_DECLARE(f)   static elog_event_type_t __ELOG_TYPE_VAR(f)
#define	ELOG_TYPE_INIT_FORMAT_AND_FUNCTION(fmt, func)   { .format = fmt, .function = func, }
#define	ELOG_TYPE_INIT(fmt)   ELOG_TYPE_INIT_FORMAT_AND_FUNCTION(fmt,(char *) __FUNCTION__)
#define	ELOG_TYPE_DECLARE_HELPER(f, fmt, func)
#define	ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION(f, fmt)   ELOG_TYPE_DECLARE_HELPER (f, fmt, (char *) __FUNCTION__)
#define	ELOG_TYPE_DECLARE_FORMAT(f, fmt)   ELOG_TYPE_DECLARE_HELPER (f, fmt, 0)
#define	ELOG_TYPE(f, fmt)   ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION(f,fmt)
#define	ELOG_TYPE_D(f)   ELOG_TYPE_DECLARE_FORMAT (f, #f " %d")
#define	ELOG_TYPE_X(f)   ELOG_TYPE_DECLARE_FORMAT (f, #f " 0x%x")
#define	ELOG_TYPE_DF(f)   ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION (f, #f " %d")
#define	ELOG_TYPE_XF(f)   ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION (f, #f " 0x%x")
#define	ELOG_TYPE_FD(f)   ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION (f, #f " %d")
#define	ELOG_TYPE_FX(f)   ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION (f, #f " 0x%x")
#define	ELOG_TRACK_DECLARE(f)   static elog_track_t __ELOG_TRACK_VAR(f)
#define	ELOG_TRACK(f)   ELOG_TRACK_DECLARE(f) = { .name = #f, }
#define	ELOG(em, f, data)   elog ((em), &__ELOG_TYPE_VAR(f), data)
#define	ELOG_INLINE(em, f, data)   elog_inline ((em), &__ELOG_TYPE_VAR(f), data)
#define	ELOG_TRACK_DATA(em, f, track)   elog_data ((em), &__ELOG_TYPE_VAR(f), &__ELOG_TRACK_VAR(track))
#define	ELOG_TRACK_DATA_INLINE(em, f, track)   elog_data_inline ((em), &__ELOG_TYPE_VAR(f), &__ELOG_TRACK_VAR(track))
#define	ELOG_DATA(em, f)   elog_data ((em), &__ELOG_TYPE_VAR (f), &(em)->default_track)
#define	ELOG_DATA_INLINE(em, f)   elog_data_inline ((em), &__ELOG_TYPE_VAR (f), &(em)->default_track)

Functions
static uword	elog_n_events_in_buffer (elog_main_t *em)
	Return number of events in the event-log buffer. More...
static uword	elog_buffer_capacity (elog_main_t *em)
	Return number of events which can fit in the event buffer. More...
static void	elog_reset_buffer (elog_main_t *em)
	Reset the event buffer. More...
static void	elog_enable_disable (elog_main_t *em, int is_enabled)
	Enable or disable event logging. More...
static void	elog_disable_after_events (elog_main_t *em, uword n)
	disable logging after specified number of ievents have been logged. More...
static void	elog_disable_trigger (elog_main_t *em)
word	elog_event_type_register (elog_main_t *em, elog_event_type_t *t)
	register an event type More...
word	elog_track_register (elog_main_t *em, elog_track_t *t)
	register an event track More...
static uword	elog_is_enabled (elog_main_t *em)
	event logging enabled predicate More...
static void *	elog_event_data_inline (elog_main_t *em, elog_event_type_t *type, elog_track_t *track, u64 cpu_time)
	Allocate an event to be filled in by the caller. More...
void *	elog_event_data (elog_main_t *em, elog_event_type_t *type, elog_track_t *track, u64 cpu_time)
static void *	elog_event_data_not_inline (elog_main_t *em, elog_event_type_t *type, elog_track_t *track, u64 cpu_time)
	Allocate an event to be filled in by the caller, non-inline. More...
static void	elog (elog_main_t *em, elog_event_type_t *type, u32 data)
	Log a single-datum event. More...
static void	elog_inline (elog_main_t *em, elog_event_type_t *type, u32 data)
	Log a single-datum event, inline version. More...
static void	elog_track (elog_main_t *em, elog_event_type_t *type, elog_track_t *track, u32 data)
	Log a single-datum event to a specific track, non-inline version. More...
static void	elog_track_inline (elog_main_t *em, elog_event_type_t *type, elog_track_t *track, u32 data)
	Log a single-datum event to a specific track. More...
static void *	elog_data (elog_main_t *em, elog_event_type_t *type, elog_track_t *track)
static void *	elog_data_inline (elog_main_t *em, elog_event_type_t *type, elog_track_t *track)
u32	elog_string (elog_main_t *em, char *format,...)
	add a string to the event-log string table More...
void	elog_time_now (elog_time_stamp_t *et)
elog_event_t *	elog_get_events (elog_main_t *em)
	convert event ring events to events, and return them as a vector. More...
elog_event_t *	elog_peek_events (elog_main_t *em)
	convert event ring events to events, and return them as a vector. More...
void	elog_merge (elog_main_t *dst, u8 *dst_tag, elog_main_t *src, u8 *src_tag, f64 align_tweak)
u8 *	format_elog_event (u8 *s, va_list *va)
u8 *	format_elog_track (u8 *s, va_list *va)
void	serialize_elog_main (serialize_main_t *m, va_list *va)
void	unserialize_elog_main (serialize_main_t *m, va_list *va)
void	elog_init (elog_main_t *em, u32 n_events)
void	elog_alloc (elog_main_t *em, u32 n_events)
static clib_error_t *	elog_write_file (elog_main_t *em, char *clib_file, int flush_ring)
static clib_error_t *	elog_read_file (elog_main_t *em, char *clib_file)

Detailed Description

The fine-grained event logger allows lightweight, thread-safe event logging at minimum cost.

In typical operation, logging a single event costs around 80ns on x86_64. It's appropriate for at-least per-frame event-logging in vector packet processing.

See https://wiki.fd.io/view/VPP/elog for more information.

Definition in file elog.h.

Macro Definition Documentation

#define ELOG	(		em,
			f,
			data
	)		elog ((em), &__ELOG_TYPE_VAR(f), data)

Definition at line 471 of file elog.h.

#define ELOG_DATA	(		em,
			f
	)		elog_data ((em), &__ELOG_TYPE_VAR (f), &(em)->default_track)

Definition at line 481 of file elog.h.

#define ELOG_DATA_INLINE	(		em,
			f
	)		elog_data_inline ((em), &__ELOG_TYPE_VAR (f), &(em)->default_track)

Definition at line 482 of file elog.h.

#define ELOG_INLINE	(		em,
			f,
			data
	)		elog_inline ((em), &__ELOG_TYPE_VAR(f), data)

Definition at line 472 of file elog.h.

#define ELOG_TRACK

(

f

)

ELOG_TRACK_DECLARE(f) = { .name = #f, }

Definition at line 468 of file elog.h.

#define ELOG_TRACK_DATA	(		em,
			f,
			track
	)		elog_data ((em), &__ELOG_TYPE_VAR(f), &__ELOG_TRACK_VAR(track))

Definition at line 475 of file elog.h.

#define ELOG_TRACK_DATA_INLINE	(		em,
			f,
			track
	)		elog_data_inline ((em), &__ELOG_TYPE_VAR(f), &__ELOG_TRACK_VAR(track))

Definition at line 477 of file elog.h.

#define ELOG_TRACK_DECLARE

(

f

)

static elog_track_t __ELOG_TRACK_VAR(f)

Definition at line 467 of file elog.h.

#define ELOG_TYPE	(		f,
			fmt
	)		ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION(f,fmt)

Definition at line 459 of file elog.h.

#define ELOG_TYPE_D

(

f

)

ELOG_TYPE_DECLARE_FORMAT (f, #f " %d")

Definition at line 460 of file elog.h.

#define ELOG_TYPE_DECLARE

(

f

)

static elog_event_type_t __ELOG_TYPE_VAR(f)

Definition at line 439 of file elog.h.

#define ELOG_TYPE_DECLARE_FORMAT	(		f,
			fmt
	)		ELOG_TYPE_DECLARE_HELPER (f, fmt, 0)

Definition at line 454 of file elog.h.

#define ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION	(		f,
			fmt
	)		ELOG_TYPE_DECLARE_HELPER (f, fmt, (char *) __FUNCTION__)

Definition at line 451 of file elog.h.

#define ELOG_TYPE_DECLARE_HELPER	(		f,
			fmt,
			func
	)

Value:

static elog_event_type_t __ELOG_TYPE_VAR(f) =           \
    ELOG_TYPE_INIT_FORMAT_AND_FUNCTION (fmt, func)

Definition at line 447 of file elog.h.

#define ELOG_TYPE_DF

(

f

)

ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION (f, #f " %d")

Definition at line 462 of file elog.h.

#define ELOG_TYPE_FD

(

f

)

ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION (f, #f " %d")

Definition at line 464 of file elog.h.

#define ELOG_TYPE_FX

(

f

)

ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION (f, #f " 0x%x")

Definition at line 465 of file elog.h.

#define ELOG_TYPE_INIT

(

fmt

)

ELOG_TYPE_INIT_FORMAT_AND_FUNCTION(fmt,(char *) __FUNCTION__)

Definition at line 444 of file elog.h.

#define ELOG_TYPE_INIT_FORMAT_AND_FUNCTION	(		fmt,
			func
	)		{ .format = fmt, .function = func, }

Definition at line 441 of file elog.h.

#define ELOG_TYPE_X

(

f

)

ELOG_TYPE_DECLARE_FORMAT (f, #f " 0x%x")

Definition at line 461 of file elog.h.

#define ELOG_TYPE_XF

(

f

)

ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION (f, #f " 0x%x")

Definition at line 463 of file elog.h.

Function Documentation

static void elog ( elog_main_t *  em, elog_event_type_t *  type, u32  data  )

inlinestatic

Log a single-datum event.

Parameters

em	elog_main_t *
type	elog_event_type_t * type
data	u32 single datum to capture

Definition at line 364 of file elog.h.

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void elog_alloc	(	elog_main_t *	em,
		u32	n_events
	)

Definition at line 452 of file elog.c.

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static uword elog_buffer_capacity ( elog_main_t *  em )

inlinestatic

Return number of events which can fit in the event buffer.

Parameters

em	elog_main_t *

Returns

number of events which can fit in the buffer

Definition at line 198 of file elog.h.

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static void* elog_data ( elog_main_t *  em, elog_event_type_t *  type, elog_track_t *  track  )

inlinestatic

Definition at line 423 of file elog.h.

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static void* elog_data_inline ( elog_main_t *  em, elog_event_type_t *  type, elog_track_t *  track  )

inlinestatic

Definition at line 429 of file elog.h.

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static void elog_disable_after_events ( elog_main_t *  em, uword  n  )

inlinestatic

disable logging after specified number of ievents have been logged.

This is used as a "debug trigger" when a certain event has occurred. Events will be logged both before and after the "event" but the event will not be lost as long as N < RING_SIZE.

Parameters

em	elog_main_t *
n	uword number of events before disabling event logging

Definition at line 233 of file elog.h.

static void elog_disable_trigger ( elog_main_t *  em )

inlinestatic

Definition at line 245 of file elog.h.

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static void elog_enable_disable ( elog_main_t *  em, int  is_enabled  )

inlinestatic

Enable or disable event logging.

Parameters

em	elog_main_t *

Definition at line 217 of file elog.h.

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void* elog_event_data	(	elog_main_t *	em,
		elog_event_type_t *	type,
		elog_track_t *	track,
		u64	cpu_time
	)

Definition at line 65 of file elog.c.

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static void* elog_event_data_inline ( elog_main_t *  em, elog_event_type_t *  type, elog_track_t *  track, u64  cpu_time  )

inlinestatic

Allocate an event to be filled in by the caller.

Not normally called directly; this function underlies the ELOG_DATA and ELOG_TRACK_DATA macros

Parameters

em	elog_main_t *
type	elog_event_type_t * type
track	elog_track_t * track
cpu_time	u64 current cpu tick value

Returns

event to be filled in

Definition at line 290 of file elog.h.

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static void* elog_event_data_not_inline ( elog_main_t *  em, elog_event_type_t *  type, elog_track_t *  track, u64  cpu_time  )

inlinestatic

Allocate an event to be filled in by the caller, non-inline.

Not normally called directly; this function underlies the ELOG_DATA and ELOG_TRACK_DATA macros

Parameters

em	elog_main_t *
type	elog_event_type_t * type
track	elog_track_t * track
cpu_time	u64 current cpu tick value

Returns

event to be filled in

Definition at line 348 of file elog.h.

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word elog_event_type_register	(	elog_main_t *	em,
		elog_event_type_t *	t
	)

register an event type

Parameters

em	elog_main_t *
t	elog_event_type_t * event to register

Returns

type index

Warning

Typically not called directly

Definition at line 104 of file elog.c.

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elog_event_t* elog_get_events

(

elog_main_t *

em

)

convert event ring events to events, and return them as a vector.

Parameters

em	elog_main_t *

Returns

event vector with timestamps in f64 seconds

Note

sets em->events to resulting vector.

Definition at line 552 of file elog.c.

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void elog_init	(	elog_main_t *	em,
		u32	n_events
	)

Definition at line 466 of file elog.c.

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static void elog_inline ( elog_main_t *  em, elog_event_type_t *  type, u32  data  )

inlinestatic

Log a single-datum event, inline version.

Parameters

em	elog_main_t *
type	elog_event_type_t * type
data	u32 single datum to capture

Definition at line 379 of file elog.h.

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static uword elog_is_enabled ( elog_main_t *  em )

inlinestatic

event logging enabled predicate

Parameters

em	elog_main_t *

Returns

1 if enabled, 0 if not enabled

Definition at line 273 of file elog.h.

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void elog_merge	(	elog_main_t *	dst,
		u8 *	dst_tag,
		elog_main_t *	src,
		u8 *	src_tag,
		f64	align_tweak
	)

Definition at line 625 of file elog.c.

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static uword elog_n_events_in_buffer ( elog_main_t *  em )

inlinestatic

Return number of events in the event-log buffer.

Parameters

em	elog_main_t *

Returns

number of events in the buffer

Definition at line 188 of file elog.h.

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elog_event_t* elog_peek_events

(

elog_main_t *

em

)

convert event ring events to events, and return them as a vector.

Parameters

em	elog_main_t *

Returns

event vector with timestamps in f64 seconds

Note

no side effects

Definition at line 509 of file elog.c.

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static clib_error_t* elog_read_file ( elog_main_t *  em, char *  clib_file  )

inlinestatic

Definition at line 543 of file elog.h.

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static void elog_reset_buffer ( elog_main_t *  em )

inlinestatic

Reset the event buffer.

Parameters

em	elog_main_t *

Definition at line 207 of file elog.h.

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u32 elog_string	(	elog_main_t *	em,
		char *	format,
			...
	)

add a string to the event-log string table

Often combined with hashing and the T4 elog format specifier to display complex strings in offline tooling

Parameters

em	elog_main_t *
format	char *
VARARGS

Returns

u32 index to add to event log

Definition at line 534 of file elog.c.

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void elog_time_now

(

elog_time_stamp_t *

et

)

Definition at line 408 of file elog.c.

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static void elog_track ( elog_main_t *  em, elog_event_type_t *  type, elog_track_t *  track, u32  data  )

inlinestatic

Log a single-datum event to a specific track, non-inline version.

Parameters

em	elog_main_t *
type	elog_event_type_t * type
type	elog_event_track_t * track
data	u32 single datum to capture

Definition at line 395 of file elog.h.

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static void elog_track_inline ( elog_main_t *  em, elog_event_type_t *  type, elog_track_t *  track, u32  data  )

inlinestatic

Log a single-datum event to a specific track.

Parameters

em	elog_main_t *
type	elog_event_type_t * type
type	elog_event_track_t * track
data	u32 single datum to capture

Definition at line 412 of file elog.h.

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word elog_track_register	(	elog_main_t *	em,
		elog_track_t *	t
	)

register an event track

Parameters

em	elog_main_t *
t	elog_track_t * track to register

Returns

track index

Note

this function is often called directly

Definition at line 198 of file elog.c.

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static clib_error_t* elog_write_file ( elog_main_t *  em, char *  clib_file, int  flush_ring  )

inlinestatic

Definition at line 528 of file elog.h.

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u8* format_elog_event	(	u8 *	s,
		va_list *	va
	)

Definition at line 296 of file elog.c.

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u8* format_elog_track	(	u8 *	s,
		va_list *	va
	)

Definition at line 399 of file elog.c.

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void serialize_elog_main	(	serialize_main_t *	m,
		va_list *	va
	)

Definition at line 1038 of file elog.c.

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void unserialize_elog_main	(	serialize_main_t *	m,
		va_list *	va
	)

Definition at line 1072 of file elog.c.

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