2 * Copyright (c) 2015 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
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10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 Copyright (c) 2005,2009 Eliot Dresselhaus
18 Permission is hereby granted, free of charge, to any person obtaining
19 a copy of this software and associated documentation files (the
20 "Software"), to deal in the Software without restriction, including
21 without limitation the rights to use, copy, modify, merge, publish,
22 distribute, sublicense, and/or sell copies of the Software, and to
23 permit persons to whom the Software is furnished to do so, subject to
24 the following conditions:
26 The above copyright notice and this permission notice shall be
27 included in all copies or substantial portions of the Software.
29 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
30 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
31 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
32 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
33 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
34 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
35 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
38 /* High speed event logger */
41 The fine-grained event logger allows lightweight, thread-safe
42 event logging at minimum cost. In typical operation, logging
43 a single event costs around 80ns on x86_64. It's appropriate
44 for at-least per-frame event-logging in vector packet processing.
46 See https://wiki.fd.io/view/VPP/elog for more information.
49 #ifndef included_clib_elog_h
50 #define included_clib_elog_h
52 #include <vppinfra/cache.h>
53 #include <vppinfra/error.h> /* for ASSERT */
54 #include <vppinfra/serialize.h>
55 #include <vppinfra/time.h> /* for clib_cpu_time_now */
56 #include <vppinfra/mhash.h>
62 /** Absolute time stamp in CPU clock cycles. */
65 /** Absolute time as floating point number in seconds. */
69 /** Event type index. */
72 /** Track for this event. Tracks allow events to be sorted and
73 displayed by track. Think of 2 dimensional display with time and
74 track being the x and y axes. */
77 /** 20-bytes of data follows, pads to 32 bytes. */
83 /** Type index plus one assigned to this type.
84 This is used to mark type as seen. */
85 u32 type_index_plus_one;
87 /** String table as a vector constructed when type is registered. */
88 char **enum_strings_vector;
90 /** Format string. (example: "my-event (%d,%d)"). */
93 /** Specifies how arguments to format are parsed from event data.
94 String of characters '0' '1' or '2' '3' to specify log2 size of data
95 (e.g. for u8, u16, u32 or u64),
96 's' means a null-terminated C string
97 't' means argument is an index into enum string table for this type.
102 /** Function name generating event. */
105 /** Number of elements in string enum table. */
108 /** String table for enum/number to string formatting. */
109 char *enum_strings[];
114 /** Track name vector. */
117 /** Set to one when track has been added to
119 u32 track_index_plus_one;
124 /** CPU cycle counter. */
127 /** OS timer in nano secs since epoch 3/30/2017, see elog_time_now() */
133 /** Total number of events in buffer. */
136 /** When count reaches limit logging is disabled. This is
137 used for event triggers. */
138 u32 n_total_events_disable_limit;
140 /** Dummy event to use when logger is disabled. */
141 elog_event_t dummy_event;
143 /** Power of 2 number of elements in ring. */
144 uword event_ring_size;
146 /** Vector of events (circular buffer). Power of 2 size.
147 Used when events are being collected. */
148 elog_event_t *event_ring;
150 /** Vector of event types. */
151 elog_event_type_t *event_types;
153 /** Hash table mapping type format to type index. */
154 uword *event_type_by_format;
156 /** Events may refer to strings in string table. */
159 /** Vector of tracks. */
160 elog_track_t *tracks;
162 /** Default track. */
163 elog_track_t default_track;
165 /** Place holder for CPU clock frequency. */
166 clib_time_t cpu_timer;
169 elog_time_stamp_t init_time, serialize_time;
171 /** SMP lock, non-zero means locking required */
174 /** Use serialize_time and init_time to give estimate for
175 cpu clock frequency. */
176 f64 nsec_per_cpu_clock;
178 /** Vector of events converted to generic form after collection. */
179 elog_event_t *events;
182 /** @brief Return number of events in the event-log buffer
183 @param em elog_main_t *
184 @return number of events in the buffer
188 elog_n_events_in_buffer (elog_main_t * em)
190 return clib_min (em->n_total_events, em->event_ring_size);
193 /** @brief Return number of events which can fit in the event buffer
194 @param em elog_main_t *
195 @return number of events which can fit in the buffer
198 elog_buffer_capacity (elog_main_t * em)
200 return em->event_ring_size;
203 /** @brief Reset the event buffer
204 @param em elog_main_t *
207 elog_reset_buffer (elog_main_t * em)
209 em->n_total_events = 0;
210 em->n_total_events_disable_limit = ~0;
213 /** @brief Enable or disable event logging
214 @param em elog_main_t *
217 elog_enable_disable (elog_main_t * em, int is_enabled)
219 em->n_total_events = 0;
220 em->n_total_events_disable_limit = is_enabled ? ~0 : 0;
223 /** @brief disable logging after specified number of ievents have been logged.
225 This is used as a "debug trigger" when a certain event has occurred.
226 Events will be logged both before and after the "event" but the
227 event will not be lost as long as N < RING_SIZE.
229 @param em elog_main_t *
230 @param n uword number of events before disabling event logging
233 elog_disable_after_events (elog_main_t * em, uword n)
235 em->n_total_events_disable_limit = em->n_total_events + n;
238 /* @brief mid-buffer logic-analyzer trigger
240 Currently, only midpoint triggering is supported, but it's pretty obvious
241 how to generalize the scheme.
242 @param em elog_main_t *
245 elog_disable_trigger (elog_main_t * em)
247 em->n_total_events_disable_limit =
248 em->n_total_events + vec_len (em->event_ring) / 2;
251 /** @brief register an event type
252 @param em elog_main_t *
253 @param t elog_event_type_t * event to register
255 @warning Typically not called directly
258 word elog_event_type_register (elog_main_t * em, elog_event_type_t * t);
260 /** @brief register an event track
261 @param em elog_main_t *
262 @param t elog_track_t * track to register
264 @note this function is often called directly
266 word elog_track_register (elog_main_t * em, elog_track_t * t);
268 /** @brief event logging enabled predicate
269 @param em elog_main_t *
270 @return 1 if enabled, 0 if not enabled
273 elog_is_enabled (elog_main_t * em)
275 return em->n_total_events < em->n_total_events_disable_limit;
278 /** @brief Allocate an event to be filled in by the caller
280 Not normally called directly; this function underlies the
281 ELOG_DATA and ELOG_TRACK_DATA macros
283 @param em elog_main_t *
284 @param type elog_event_type_t * type
285 @param track elog_track_t * track
286 @param cpu_time u64 current cpu tick value
287 @returns event to be filled in
290 elog_event_data_inline (elog_main_t * em,
291 elog_event_type_t * type,
292 elog_track_t * track, u64 cpu_time)
296 word type_index, track_index;
298 /* Return the user dummy memory to scribble data into. */
299 if (PREDICT_FALSE (!elog_is_enabled (em)))
300 return em->dummy_event.data;
302 type_index = (word) type->type_index_plus_one - 1;
303 track_index = (word) track->track_index_plus_one - 1;
304 if (PREDICT_FALSE ((type_index | track_index) < 0))
307 type_index = elog_event_type_register (em, type);
309 track_index = elog_track_register (em, track);
312 ASSERT (track_index < vec_len (em->tracks));
313 ASSERT (is_pow2 (vec_len (em->event_ring)));
316 ei = clib_atomic_fetch_add (&em->n_total_events, 1);
318 ei = em->n_total_events++;
320 ei &= em->event_ring_size - 1;
321 e = vec_elt_at_index (em->event_ring, ei);
323 e->time_cycles = cpu_time;
324 e->type = type_index;
325 e->track = track_index;
327 /* Return user data for caller to fill in. */
331 /* External version of inline. */
332 void *elog_event_data (elog_main_t * em,
333 elog_event_type_t * type,
334 elog_track_t * track, u64 cpu_time);
336 /** @brief Allocate an event to be filled in by the caller, non-inline
338 Not normally called directly; this function underlies the
339 ELOG_DATA and ELOG_TRACK_DATA macros
341 @param em elog_main_t *
342 @param type elog_event_type_t * type
343 @param track elog_track_t * track
344 @param cpu_time u64 current cpu tick value
345 @returns event to be filled in
348 elog_event_data_not_inline (elog_main_t * em,
349 elog_event_type_t * type,
350 elog_track_t * track, u64 cpu_time)
352 /* Return the user dummy memory to scribble data into. */
353 if (PREDICT_FALSE (!elog_is_enabled (em)))
354 return em->dummy_event.data;
355 return elog_event_data (em, type, track, cpu_time);
358 /** @brief Log a single-datum event
359 @param em elog_main_t *
360 @param type elog_event_type_t * type
361 @param data u32 single datum to capture
364 elog (elog_main_t * em, elog_event_type_t * type, u32 data)
366 u32 *d = elog_event_data_not_inline (em,
369 clib_cpu_time_now ());
373 /** @brief Log a single-datum event, inline version
374 @param em elog_main_t *
375 @param type elog_event_type_t * type
376 @param data u32 single datum to capture
379 elog_inline (elog_main_t * em, elog_event_type_t * type, u32 data)
381 u32 *d = elog_event_data_inline (em,
384 clib_cpu_time_now ());
388 /** @brief Log a single-datum event to a specific track, non-inline version
389 @param em elog_main_t *
390 @param type elog_event_type_t * type
391 @param type elog_event_track_t * track
392 @param data u32 single datum to capture
395 elog_track (elog_main_t * em, elog_event_type_t * type, elog_track_t * track,
398 u32 *d = elog_event_data_not_inline (em,
401 clib_cpu_time_now ());
405 /** @brief Log a single-datum event to a specific track
406 @param em elog_main_t *
407 @param type elog_event_type_t * type
408 @param type elog_event_track_t * track
409 @param data u32 single datum to capture
412 elog_track_inline (elog_main_t * em, elog_event_type_t * type,
413 elog_track_t * track, u32 data)
415 u32 *d = elog_event_data_inline (em,
418 clib_cpu_time_now ());
423 elog_data (elog_main_t * em, elog_event_type_t * type, elog_track_t * track)
425 return elog_event_data_not_inline (em, type, track, clib_cpu_time_now ());
429 elog_data_inline (elog_main_t * em, elog_event_type_t * type,
430 elog_track_t * track)
432 return elog_event_data_inline (em, type, track, clib_cpu_time_now ());
435 /* Macro shorthands for generating/declaring events. */
436 #define __ELOG_TYPE_VAR(f) f
437 #define __ELOG_TRACK_VAR(f) f
439 #define ELOG_TYPE_DECLARE(f) static elog_event_type_t __ELOG_TYPE_VAR(f)
441 #define ELOG_TYPE_INIT_FORMAT_AND_FUNCTION(fmt,func) \
442 { .format = fmt, .function = func, }
444 #define ELOG_TYPE_INIT(fmt) \
445 ELOG_TYPE_INIT_FORMAT_AND_FUNCTION(fmt,(char *) __FUNCTION__)
447 #define ELOG_TYPE_DECLARE_HELPER(f,fmt,func) \
448 static elog_event_type_t __ELOG_TYPE_VAR(f) = \
449 ELOG_TYPE_INIT_FORMAT_AND_FUNCTION (fmt, func)
451 #define ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION(f,fmt) \
452 ELOG_TYPE_DECLARE_HELPER (f, fmt, (char *) __FUNCTION__)
454 #define ELOG_TYPE_DECLARE_FORMAT(f,fmt) \
455 ELOG_TYPE_DECLARE_HELPER (f, fmt, 0)
457 /* Shorthands with and without __FUNCTION__.
458 D for decimal; X for hex. F for __FUNCTION__. */
459 #define ELOG_TYPE(f,fmt) ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION(f,fmt)
460 #define ELOG_TYPE_D(f) ELOG_TYPE_DECLARE_FORMAT (f, #f " %d")
461 #define ELOG_TYPE_X(f) ELOG_TYPE_DECLARE_FORMAT (f, #f " 0x%x")
462 #define ELOG_TYPE_DF(f) ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION (f, #f " %d")
463 #define ELOG_TYPE_XF(f) ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION (f, #f " 0x%x")
464 #define ELOG_TYPE_FD(f) ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION (f, #f " %d")
465 #define ELOG_TYPE_FX(f) ELOG_TYPE_DECLARE_FORMAT_AND_FUNCTION (f, #f " 0x%x")
467 #define ELOG_TRACK_DECLARE(f) static elog_track_t __ELOG_TRACK_VAR(f)
468 #define ELOG_TRACK(f) ELOG_TRACK_DECLARE(f) = { .name = #f, }
470 /* Log 32 bits of data. */
471 #define ELOG(em,f,data) elog ((em), &__ELOG_TYPE_VAR(f), data)
472 #define ELOG_INLINE(em,f,data) elog_inline ((em), &__ELOG_TYPE_VAR(f), data)
474 /* Return data pointer to fill in. */
475 #define ELOG_TRACK_DATA(em,f,track) \
476 elog_data ((em), &__ELOG_TYPE_VAR(f), &__ELOG_TRACK_VAR(track))
477 #define ELOG_TRACK_DATA_INLINE(em,f,track) \
478 elog_data_inline ((em), &__ELOG_TYPE_VAR(f), &__ELOG_TRACK_VAR(track))
480 /* Shorthand with default track. */
481 #define ELOG_DATA(em,f) elog_data ((em), &__ELOG_TYPE_VAR (f), &(em)->default_track)
482 #define ELOG_DATA_INLINE(em,f) elog_data_inline ((em), &__ELOG_TYPE_VAR (f), &(em)->default_track)
484 /** @brief add a string to the event-log string table
486 Often combined with hashing and the T4 elog format specifier to
487 display complex strings in offline tooling
489 @param em elog_main_t *
492 @return u32 index to add to event log
494 u32 elog_string (elog_main_t * em, char *format, ...);
496 void elog_time_now (elog_time_stamp_t * et);
498 /** @brief convert event ring events to events, and return them as a vector.
499 @param em elog_main_t *
500 @return event vector with timestamps in f64 seconds
501 @note sets em->events to resulting vector.
503 elog_event_t *elog_get_events (elog_main_t * em);
505 /** @brief convert event ring events to events, and return them as a vector.
506 @param em elog_main_t *
507 @return event vector with timestamps in f64 seconds
508 @note no side effects
510 elog_event_t *elog_peek_events (elog_main_t * em);
512 /* Merge two logs, add supplied track tags. */
513 void elog_merge (elog_main_t * dst, u8 * dst_tag,
514 elog_main_t * src, u8 * src_tag, f64 align_tweak);
516 /* 2 arguments elog_main_t and elog_event_t to format event or track name. */
517 u8 *format_elog_event (u8 * s, va_list * va);
518 u8 *format_elog_track_name (u8 * s, va_list * va);
519 u8 *format_elog_track (u8 * s, va_list * args);
521 void serialize_elog_main (serialize_main_t * m, va_list * va);
522 void unserialize_elog_main (serialize_main_t * m, va_list * va);
524 void elog_init (elog_main_t * em, u32 n_events);
525 void elog_alloc (elog_main_t * em, u32 n_events);
528 always_inline clib_error_t *
529 elog_write_file (elog_main_t * em, char *clib_file, int flush_ring)
534 error = serialize_open_clib_file (&m, clib_file);
537 error = serialize (&m, serialize_elog_main, em, flush_ring);
539 serialize_close (&m);
543 always_inline clib_error_t *
544 elog_read_file (elog_main_t * em, char *clib_file)
549 error = unserialize_open_clib_file (&m, clib_file);
552 error = unserialize (&m, unserialize_elog_main, em);
554 unserialize_close (&m);
558 #endif /* CLIB_UNIX */
560 #endif /* included_clib_elog_h */
563 * fd.io coding-style-patch-verification: ON
566 * eval: (c-set-style "gnu")