Unregister tracepoint probes when not needed
[lttng-ust.git] / include / lttng / ust-events.h
1 #ifndef _LTTNG_UST_EVENTS_H
2 #define _LTTNG_UST_EVENTS_H
3
4 /*
5 * lttng/ust-events.h
6 *
7 * Copyright 2010-2012 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 *
9 * Holds LTTng per-session event registry.
10 *
11 * Permission is hereby granted, free of charge, to any person obtaining a copy
12 * of this software and associated documentation files (the "Software"), to deal
13 * in the Software without restriction, including without limitation the rights
14 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
15 * copies of the Software, and to permit persons to whom the Software is
16 * furnished to do so, subject to the following conditions:
17 *
18 * The above copyright notice and this permission notice shall be included in
19 * all copies or substantial portions of the Software.
20 *
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
22 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
24 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
25 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
26 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
27 * SOFTWARE.
28 */
29
30 #include <urcu/list.h>
31 #include <urcu/hlist.h>
32 #include <stdint.h>
33 #include <lttng/ust-abi.h>
34 #include <lttng/ust-tracer.h>
35 #include <lttng/ust-endian.h>
36 #include <float.h>
37
38 #define LTTNG_UST_UUID_LEN 16
39
40 struct lttng_channel;
41 struct lttng_session;
42 struct lttng_ust_lib_ring_buffer_ctx;
43
44 /*
45 * Data structures used by tracepoint event declarations, and by the
46 * tracer. Those structures have padding for future extension.
47 */
48
49 /*
50 * LTTng client type enumeration. Used by the consumer to map the
51 * callbacks from its own address space.
52 */
53 enum lttng_client_types {
54 LTTNG_CLIENT_METADATA = 0,
55 LTTNG_CLIENT_DISCARD = 1,
56 LTTNG_CLIENT_OVERWRITE = 2,
57 LTTNG_NR_CLIENT_TYPES,
58 };
59
60 /* Type description */
61
62 /* Update the astract_types name table in lttng-types.c along with this enum */
63 enum lttng_abstract_types {
64 atype_integer,
65 atype_enum,
66 atype_array,
67 atype_sequence,
68 atype_string,
69 atype_float,
70 NR_ABSTRACT_TYPES,
71 };
72
73 /* Update the string_encodings name table in lttng-types.c along with this enum */
74 enum lttng_string_encodings {
75 lttng_encode_none = 0,
76 lttng_encode_UTF8 = 1,
77 lttng_encode_ASCII = 2,
78 NR_STRING_ENCODINGS,
79 };
80
81 #define LTTNG_UST_ENUM_ENTRY_PADDING 16
82 struct lttng_enum_entry {
83 unsigned long long start, end; /* start and end are inclusive */
84 const char *string;
85 char padding[LTTNG_UST_ENUM_ENTRY_PADDING];
86 };
87
88 #define __type_integer(_type, _byte_order, _base, _encoding) \
89 { \
90 .atype = atype_integer, \
91 .u.basic.integer = \
92 { \
93 .size = sizeof(_type) * CHAR_BIT, \
94 .alignment = lttng_alignof(_type) * CHAR_BIT, \
95 .signedness = lttng_is_signed_type(_type), \
96 .reverse_byte_order = _byte_order != BYTE_ORDER, \
97 .base = _base, \
98 .encoding = lttng_encode_##_encoding, \
99 }, \
100 } \
101
102 #define LTTNG_UST_INTEGER_TYPE_PADDING 24
103 struct lttng_integer_type {
104 unsigned int size; /* in bits */
105 unsigned short alignment; /* in bits */
106 unsigned int signedness:1;
107 unsigned int reverse_byte_order:1;
108 unsigned int base; /* 2, 8, 10, 16, for pretty print */
109 enum lttng_string_encodings encoding;
110 char padding[LTTNG_UST_INTEGER_TYPE_PADDING];
111 };
112
113 /*
114 * Only float and double are supported. long double is not supported at
115 * the moment.
116 */
117 #define _float_mant_dig(_type) \
118 (sizeof(_type) == sizeof(float) ? FLT_MANT_DIG \
119 : (sizeof(_type) == sizeof(double) ? DBL_MANT_DIG \
120 : 0))
121
122 #define __type_float(_type) \
123 { \
124 .atype = atype_float, \
125 .u.basic._float = \
126 { \
127 .exp_dig = sizeof(_type) * CHAR_BIT \
128 - _float_mant_dig(_type), \
129 .mant_dig = _float_mant_dig(_type), \
130 .alignment = lttng_alignof(_type) * CHAR_BIT, \
131 .reverse_byte_order = BYTE_ORDER != FLOAT_WORD_ORDER, \
132 }, \
133 } \
134
135 #define LTTNG_UST_FLOAT_TYPE_PADDING 24
136 struct lttng_float_type {
137 unsigned int exp_dig; /* exponent digits, in bits */
138 unsigned int mant_dig; /* mantissa digits, in bits */
139 unsigned short alignment; /* in bits */
140 unsigned int reverse_byte_order:1;
141 char padding[LTTNG_UST_FLOAT_TYPE_PADDING];
142 };
143
144 #define LTTNG_UST_BASIC_TYPE_PADDING 128
145 union _lttng_basic_type {
146 struct lttng_integer_type integer;
147 struct {
148 const char *name;
149 } enumeration;
150 struct {
151 enum lttng_string_encodings encoding;
152 } string;
153 struct lttng_float_type _float;
154 char padding[LTTNG_UST_BASIC_TYPE_PADDING];
155 };
156
157 struct lttng_basic_type {
158 enum lttng_abstract_types atype;
159 union {
160 union _lttng_basic_type basic;
161 } u;
162 };
163
164 #define LTTNG_UST_TYPE_PADDING 128
165 struct lttng_type {
166 enum lttng_abstract_types atype;
167 union {
168 union _lttng_basic_type basic;
169 struct {
170 struct lttng_basic_type elem_type;
171 unsigned int length; /* num. elems. */
172 } array;
173 struct {
174 struct lttng_basic_type length_type;
175 struct lttng_basic_type elem_type;
176 } sequence;
177 char padding[LTTNG_UST_TYPE_PADDING];
178 } u;
179 };
180
181 #define LTTNG_UST_ENUM_TYPE_PADDING 24
182 struct lttng_enum {
183 const char *name;
184 struct lttng_type container_type;
185 const struct lttng_enum_entry *entries;
186 unsigned int len;
187 char padding[LTTNG_UST_ENUM_TYPE_PADDING];
188 };
189
190 /*
191 * Event field description
192 *
193 * IMPORTANT: this structure is part of the ABI between the probe and
194 * UST. Fields need to be only added at the end, never reordered, never
195 * removed.
196 */
197
198 #define LTTNG_UST_EVENT_FIELD_PADDING 28
199 struct lttng_event_field {
200 const char *name;
201 struct lttng_type type;
202 unsigned int nowrite; /* do not write into trace */
203 char padding[LTTNG_UST_EVENT_FIELD_PADDING];
204 };
205
206 #define LTTNG_UST_CTX_FIELD_PADDING 40
207 struct lttng_ctx_field {
208 struct lttng_event_field event_field;
209 size_t (*get_size)(size_t offset);
210 void (*record)(struct lttng_ctx_field *field,
211 struct lttng_ust_lib_ring_buffer_ctx *ctx,
212 struct lttng_channel *chan);
213 union {
214 char padding[LTTNG_UST_CTX_FIELD_PADDING];
215 } u;
216 void (*destroy)(struct lttng_ctx_field *field);
217 };
218
219 #define LTTNG_UST_CTX_PADDING 24
220 struct lttng_ctx {
221 struct lttng_ctx_field *fields;
222 unsigned int nr_fields;
223 unsigned int allocated_fields;
224 char padding[LTTNG_UST_CTX_PADDING];
225 };
226
227 #define LTTNG_UST_EVENT_DESC_PADDING 40
228 struct lttng_event_desc {
229 const char *name;
230 void (*probe_callback)(void);
231 const struct lttng_event_ctx *ctx; /* context */
232 const struct lttng_event_field *fields; /* event payload */
233 unsigned int nr_fields;
234 const int **loglevel;
235 const char *signature; /* Argument types/names received */
236 union {
237 struct {
238 const char **model_emf_uri;
239 } ext;
240 char padding[LTTNG_UST_EVENT_DESC_PADDING];
241 } u;
242 };
243
244 #define LTTNG_UST_PROBE_DESC_PADDING 20
245 struct lttng_probe_desc {
246 const char *provider;
247 const struct lttng_event_desc **event_desc;
248 unsigned int nr_events;
249 struct cds_list_head head; /* chain registered probes */
250 struct cds_list_head lazy_init_head;
251 int lazy; /* lazy registration */
252 char padding[LTTNG_UST_PROBE_DESC_PADDING];
253 };
254
255 /* Data structures used by the tracer. */
256
257 enum lttng_enabler_type {
258 LTTNG_ENABLER_WILDCARD,
259 LTTNG_ENABLER_EVENT,
260 };
261
262 /*
263 * Enabler field, within whatever object is enabling an event. Target of
264 * backward reference.
265 */
266 struct lttng_enabler {
267 enum lttng_enabler_type type;
268
269 /* head list of struct lttng_ust_filter_bytecode_node */
270 struct cds_list_head filter_bytecode_head;
271 struct cds_list_head node; /* per-session list of enablers */
272
273 struct lttng_ust_event event_param;
274 struct lttng_channel *chan;
275 struct lttng_ctx *ctx;
276 unsigned int enabled:1;
277 };
278
279 struct tp_list_entry {
280 struct lttng_ust_tracepoint_iter tp;
281 struct cds_list_head head;
282 };
283
284 struct lttng_ust_tracepoint_list {
285 struct tp_list_entry *iter;
286 struct cds_list_head head;
287 };
288
289 struct tp_field_list_entry {
290 struct lttng_ust_field_iter field;
291 struct cds_list_head head;
292 };
293
294 struct lttng_ust_field_list {
295 struct tp_field_list_entry *iter;
296 struct cds_list_head head;
297 };
298
299 struct ust_pending_probe;
300 struct lttng_event;
301
302 struct lttng_ust_filter_bytecode_node {
303 struct cds_list_head node;
304 struct lttng_enabler *enabler;
305 /*
306 * struct lttng_ust_filter_bytecode has var. sized array, must
307 * be last field.
308 */
309 struct lttng_ust_filter_bytecode bc;
310 };
311
312 /*
313 * Filter return value masks.
314 */
315 enum lttng_filter_ret {
316 LTTNG_FILTER_DISCARD = 0,
317 LTTNG_FILTER_RECORD_FLAG = (1ULL << 0),
318 /* Other bits are kept for future use. */
319 };
320
321 struct lttng_bytecode_runtime {
322 /* Associated bytecode */
323 struct lttng_ust_filter_bytecode_node *bc;
324 uint64_t (*filter)(void *filter_data, const char *filter_stack_data);
325 int link_failed;
326 struct cds_list_head node; /* list of bytecode runtime in event */
327 };
328
329 /*
330 * Objects in a linked-list of enablers, owned by an event.
331 */
332 struct lttng_enabler_ref {
333 struct cds_list_head node; /* enabler ref list */
334 struct lttng_enabler *ref; /* backward ref */
335 };
336
337 /*
338 * lttng_event structure is referred to by the tracing fast path. It
339 * must be kept small.
340 *
341 * IMPORTANT: this structure is part of the ABI between the probe and
342 * UST. Fields need to be only added at the end, never reordered, never
343 * removed.
344 */
345 struct lttng_event {
346 /* LTTng-UST 2.0 starts here */
347 unsigned int id;
348 struct lttng_channel *chan;
349 int enabled;
350 const struct lttng_event_desc *desc;
351 void *_deprecated1;
352 struct lttng_ctx *ctx;
353 enum lttng_ust_instrumentation instrumentation;
354 union {
355 } u;
356 struct cds_list_head node; /* Event list in session */
357 struct cds_list_head _deprecated2;
358 void *_deprecated3;
359 unsigned int _deprecated4:1;
360
361 /* LTTng-UST 2.1 starts here */
362 /* list of struct lttng_bytecode_runtime, sorted by seqnum */
363 struct cds_list_head bytecode_runtime_head;
364 int has_enablers_without_bytecode;
365 /* Backward references: list of lttng_enabler_ref (ref to enablers) */
366 struct cds_list_head enablers_ref_head;
367 struct cds_hlist_node hlist; /* session ht of events */
368 int registered; /* has reg'd tracepoint probe */
369 };
370
371 struct channel;
372 struct lttng_ust_shm_handle;
373
374 /*
375 * IMPORTANT: this structure is part of the ABI between the probe and
376 * UST. Fields need to be only added at the end, never reordered, never
377 * removed.
378 */
379 struct lttng_channel_ops {
380 struct lttng_channel *(*channel_create)(const char *name,
381 void *buf_addr,
382 size_t subbuf_size, size_t num_subbuf,
383 unsigned int switch_timer_interval,
384 unsigned int read_timer_interval,
385 unsigned char *uuid);
386 void (*channel_destroy)(struct lttng_channel *chan);
387 int (*event_reserve)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
388 uint32_t event_id);
389 void (*event_commit)(struct lttng_ust_lib_ring_buffer_ctx *ctx);
390 void (*event_write)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
391 const void *src, size_t len);
392 /*
393 * packet_avail_size returns the available size in the current
394 * packet. Note that the size returned is only a hint, since it
395 * may change due to concurrent writes.
396 */
397 size_t (*packet_avail_size)(struct channel *chan,
398 struct lttng_ust_shm_handle *handle);
399 //wait_queue_head_t *(*get_reader_wait_queue)(struct channel *chan);
400 //wait_queue_head_t *(*get_hp_wait_queue)(struct channel *chan);
401 int (*is_finalized)(struct channel *chan);
402 int (*is_disabled)(struct channel *chan);
403 int (*flush_buffer)(struct channel *chan, struct lttng_ust_shm_handle *handle);
404 };
405
406 /*
407 * IMPORTANT: this structure is part of the ABI between the probe and
408 * UST. Fields need to be only added at the end, never reordered, never
409 * removed.
410 */
411 struct lttng_channel {
412 /*
413 * The pointers located in this private data are NOT safe to be
414 * dereferenced by the consumer. The only operations the
415 * consumer process is designed to be allowed to do is to read
416 * and perform subbuffer flush.
417 */
418 struct channel *chan; /* Channel buffers */
419 int enabled;
420 struct lttng_ctx *ctx;
421 /* Event ID management */
422 struct lttng_session *session;
423 int objd; /* Object associated to channel */
424 unsigned int _deprecated1;
425 unsigned int _deprecated2;
426 struct cds_list_head node; /* Channel list in session */
427 const struct lttng_channel_ops *ops;
428 int header_type; /* 0: unset, 1: compact, 2: large */
429 struct lttng_ust_shm_handle *handle; /* shared-memory handle */
430 unsigned int _deprecated3:1;
431
432 /* Channel ID */
433 unsigned int id;
434 enum lttng_ust_chan_type type;
435 unsigned char uuid[LTTNG_UST_UUID_LEN]; /* Trace session unique ID */
436 int tstate:1; /* Transient enable state */
437 };
438
439 #define LTTNG_UST_EVENT_HT_BITS 12
440 #define LTTNG_UST_EVENT_HT_SIZE (1U << LTTNG_UST_EVENT_HT_BITS)
441
442 struct lttng_ust_event_ht {
443 struct cds_hlist_head table[LTTNG_UST_EVENT_HT_SIZE];
444 };
445
446 /*
447 * IMPORTANT: this structure is part of the ABI between the probe and
448 * UST. Fields need to be only added at the end, never reordered, never
449 * removed.
450 */
451 struct lttng_session {
452 int active; /* Is trace session active ? */
453 int been_active; /* Been active ? */
454 int objd; /* Object associated */
455 void *_deprecated1;
456 struct cds_list_head chan_head; /* Channel list head */
457 struct cds_list_head events_head; /* list of events */
458 struct cds_list_head _deprecated2;
459 struct cds_list_head node; /* Session list */
460 int _deprecated3;
461 unsigned int _deprecated4:1;
462
463 /* New UST 2.1 */
464 /* List of enablers */
465 struct cds_list_head enablers_head;
466 struct lttng_ust_event_ht events_ht; /* ht of events */
467 void *owner; /* object owner */
468 int tstate:1; /* Transient enable state */
469 };
470
471 struct lttng_transport {
472 char *name;
473 struct cds_list_head node;
474 struct lttng_channel_ops ops;
475 const struct lttng_ust_lib_ring_buffer_config *client_config;
476 };
477
478 struct lttng_session *lttng_session_create(void);
479 int lttng_session_enable(struct lttng_session *session);
480 int lttng_session_disable(struct lttng_session *session);
481 void lttng_session_destroy(struct lttng_session *session);
482
483 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
484 const char *transport_name,
485 void *buf_addr,
486 size_t subbuf_size, size_t num_subbuf,
487 unsigned int switch_timer_interval,
488 unsigned int read_timer_interval,
489 int **shm_fd, int **wait_fd,
490 uint64_t **memory_map_size,
491 struct lttng_channel *chan_priv_init);
492
493 int lttng_channel_enable(struct lttng_channel *channel);
494 int lttng_channel_disable(struct lttng_channel *channel);
495
496 struct lttng_enabler *lttng_enabler_create(enum lttng_enabler_type type,
497 struct lttng_ust_event *event_param,
498 struct lttng_channel *chan);
499 int lttng_enabler_enable(struct lttng_enabler *enabler);
500 int lttng_enabler_disable(struct lttng_enabler *enabler);
501 int lttng_enabler_attach_bytecode(struct lttng_enabler *enabler,
502 struct lttng_ust_filter_bytecode_node *bytecode);
503 int lttng_enabler_attach_context(struct lttng_enabler *enabler,
504 struct lttng_ust_context *ctx);
505
506 int lttng_attach_context(struct lttng_ust_context *context_param,
507 struct lttng_ctx **ctx, struct lttng_session *session);
508
509 void lttng_transport_register(struct lttng_transport *transport);
510 void lttng_transport_unregister(struct lttng_transport *transport);
511
512 void synchronize_trace(void);
513
514 int lttng_probe_register(struct lttng_probe_desc *desc);
515 void lttng_probe_unregister(struct lttng_probe_desc *desc);
516 int lttng_fix_pending_event_desc(const struct lttng_event_desc *desc);
517 int lttng_probes_init(void);
518 void lttng_probes_exit(void);
519 int lttng_find_context(struct lttng_ctx *ctx, const char *name);
520 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p);
521 void lttng_remove_context_field(struct lttng_ctx **ctx_p,
522 struct lttng_ctx_field *field);
523 void lttng_destroy_context(struct lttng_ctx *ctx);
524 int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
525 int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx);
526 int lttng_add_pthread_id_to_ctx(struct lttng_ctx **ctx);
527 int lttng_add_procname_to_ctx(struct lttng_ctx **ctx);
528 void lttng_context_vtid_reset(void);
529 void lttng_context_vpid_reset(void);
530
531 extern const struct lttng_ust_lib_ring_buffer_client_cb *lttng_client_callbacks_metadata;
532 extern const struct lttng_ust_lib_ring_buffer_client_cb *lttng_client_callbacks_discard;
533 extern const struct lttng_ust_lib_ring_buffer_client_cb *lttng_client_callbacks_overwrite;
534
535 struct lttng_transport *lttng_transport_find(const char *name);
536
537 int lttng_probes_get_event_list(struct lttng_ust_tracepoint_list *list);
538 void lttng_probes_prune_event_list(struct lttng_ust_tracepoint_list *list);
539 struct lttng_ust_tracepoint_iter *
540 lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list);
541 int lttng_probes_get_field_list(struct lttng_ust_field_list *list);
542 void lttng_probes_prune_field_list(struct lttng_ust_field_list *list);
543 struct lttng_ust_field_iter *
544 lttng_ust_field_list_get_iter_next(struct lttng_ust_field_list *list);
545
546 void lttng_filter_event_link_bytecode(struct lttng_event *event);
547 void lttng_enabler_event_link_bytecode(struct lttng_event *event,
548 struct lttng_enabler *enabler);
549 void lttng_free_event_filter_runtime(struct lttng_event *event);
550 void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime);
551
552 struct cds_list_head *lttng_get_probe_list_head(void);
553 int lttng_session_active(void);
554
555 #endif /* _LTTNG_UST_EVENTS_H */
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