4 * Holds LTTng per-session event registry.
6 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; only
11 * version 2.1 of the License.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 #include <urcu/list.h>
26 #include <urcu/hlist.h>
35 #include <lttng/ust-endian.h>
39 #include <urcu/compiler.h>
40 #include <urcu/uatomic.h>
41 #include <urcu/arch.h>
43 #include <lttng/tracepoint.h>
44 #include <lttng/ust-events.h>
46 #include <usterr-signal-safe.h>
50 #include "lttng-ust-uuid.h"
52 #include "tracepoint-internal.h"
53 #include "lttng-tracer.h"
54 #include "lttng-tracer-core.h"
56 #include "../libringbuffer/shm.h"
60 * The sessions mutex is the centralized mutex across UST tracing
61 * control and probe registration. All operations within this file are
62 * called by the communication thread, under ust_lock protection.
64 static pthread_mutex_t sessions_mutex
= PTHREAD_MUTEX_INITIALIZER
;
68 pthread_mutex_lock(&sessions_mutex
);
73 pthread_mutex_unlock(&sessions_mutex
);
76 static CDS_LIST_HEAD(sessions
);
78 static void _lttng_event_destroy(struct lttng_event
*event
);
79 static int _lttng_event_unregister(struct lttng_event
*event
);
81 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
82 struct lttng_channel
*chan
,
83 struct lttng_event
*event
);
85 int _lttng_session_metadata_statedump(struct lttng_session
*session
);
88 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
);
90 void lttng_session_sync_enablers(struct lttng_session
*session
);
92 void lttng_enabler_destroy(struct lttng_enabler
*enabler
);
95 int lttng_loglevel_match(int loglevel
,
96 unsigned int has_loglevel
,
97 enum lttng_ust_loglevel_type req_type
,
100 if (req_type
== LTTNG_UST_LOGLEVEL_ALL
)
103 loglevel
= TRACE_DEFAULT
;
105 case LTTNG_UST_LOGLEVEL_RANGE
:
106 if (loglevel
<= req_loglevel
|| req_loglevel
== -1)
110 case LTTNG_UST_LOGLEVEL_SINGLE
:
111 if (loglevel
== req_loglevel
|| req_loglevel
== -1)
115 case LTTNG_UST_LOGLEVEL_ALL
:
121 void synchronize_trace(void)
126 struct lttng_session
*lttng_session_create(void)
128 struct lttng_session
*session
;
131 session
= zmalloc(sizeof(struct lttng_session
));
134 CDS_INIT_LIST_HEAD(&session
->chan_head
);
135 CDS_INIT_LIST_HEAD(&session
->events_head
);
136 CDS_INIT_LIST_HEAD(&session
->enablers_head
);
137 for (i
= 0; i
< LTTNG_UST_EVENT_HT_SIZE
; i
++)
138 CDS_INIT_HLIST_HEAD(&session
->events_ht
.table
[i
]);
139 cds_list_add(&session
->node
, &sessions
);
144 * Only used internally at session destruction.
147 void _lttng_channel_unmap(struct lttng_channel
*lttng_chan
)
149 struct channel
*chan
;
150 struct lttng_ust_shm_handle
*handle
;
152 cds_list_del(<tng_chan
->node
);
153 lttng_destroy_context(lttng_chan
->ctx
);
154 chan
= lttng_chan
->chan
;
155 handle
= lttng_chan
->handle
;
157 * note: lttng_chan is private data contained within handle. It
158 * will be freed along with the handle.
160 channel_destroy(chan
, handle
, 0);
163 void lttng_session_destroy(struct lttng_session
*session
)
165 struct lttng_channel
*chan
, *tmpchan
;
166 struct lttng_event
*event
, *tmpevent
;
167 struct lttng_enabler
*enabler
, *tmpenabler
;
170 CMM_ACCESS_ONCE(session
->active
) = 0;
171 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
172 ret
= _lttng_event_unregister(event
);
175 synchronize_trace(); /* Wait for in-flight events to complete */
176 cds_list_for_each_entry_safe(enabler
, tmpenabler
,
177 &session
->enablers_head
, node
)
178 lttng_enabler_destroy(enabler
);
179 cds_list_for_each_entry_safe(event
, tmpevent
,
180 &session
->events_head
, node
)
181 _lttng_event_destroy(event
);
182 cds_list_for_each_entry_safe(chan
, tmpchan
, &session
->chan_head
, node
)
183 _lttng_channel_unmap(chan
);
184 cds_list_del(&session
->node
);
188 int lttng_session_enable(struct lttng_session
*session
)
191 struct lttng_channel
*chan
;
193 if (session
->active
) {
198 /* We need to sync enablers with session before activation. */
199 lttng_session_sync_enablers(session
);
202 * Snapshot the number of events per channel to know the type of header
205 cds_list_for_each_entry(chan
, &session
->chan_head
, node
) {
206 if (chan
->header_type
)
207 continue; /* don't change it if session stop/restart */
208 if (chan
->free_event_id
< 31)
209 chan
->header_type
= 1; /* compact */
211 chan
->header_type
= 2; /* large */
214 CMM_ACCESS_ONCE(session
->active
) = 1;
215 CMM_ACCESS_ONCE(session
->been_active
) = 1;
216 ret
= _lttng_session_metadata_statedump(session
);
218 CMM_ACCESS_ONCE(session
->active
) = 0;
223 int lttng_session_disable(struct lttng_session
*session
)
227 if (!session
->active
) {
231 CMM_ACCESS_ONCE(session
->active
) = 0;
236 int lttng_channel_enable(struct lttng_channel
*channel
)
240 if (channel
== channel
->session
->metadata
)
242 old
= uatomic_xchg(&channel
->enabled
, 1);
248 int lttng_channel_disable(struct lttng_channel
*channel
)
252 if (channel
== channel
->session
->metadata
)
254 old
= uatomic_xchg(&channel
->enabled
, 0);
260 int lttng_event_enable(struct lttng_event
*event
)
264 if (event
->chan
== event
->chan
->session
->metadata
)
266 old
= uatomic_xchg(&event
->enabled
, 1);
272 int lttng_event_disable(struct lttng_event
*event
)
276 if (event
->chan
== event
->chan
->session
->metadata
)
278 old
= uatomic_xchg(&event
->enabled
, 0);
285 * Supports event creation while tracing session is active.
288 int lttng_event_create(const struct lttng_event_desc
*desc
,
289 struct lttng_channel
*chan
)
291 const char *event_name
= desc
->name
;
292 struct lttng_event
*event
;
293 struct cds_hlist_head
*head
;
294 struct cds_hlist_node
*node
;
296 size_t name_len
= strlen(event_name
);
299 if (chan
->used_event_id
== -1U) {
303 hash
= jhash(event_name
, name_len
, 0);
304 head
= &chan
->session
->events_ht
.table
[hash
& (LTTNG_UST_EVENT_HT_SIZE
- 1)];
305 cds_hlist_for_each_entry(event
, node
, head
, hlist
) {
307 if (!strncmp(event
->desc
->name
,
309 LTTNG_UST_SYM_NAME_LEN
- 1)) {
316 * Check if loglevel match. Refuse to connect event if not.
318 event
= zmalloc(sizeof(struct lttng_event
));
326 * used_event_id counts the maximum number of event IDs that can
327 * register if all probes register.
329 chan
->used_event_id
++;
331 CDS_INIT_LIST_HEAD(&event
->bytecode_runtime_head
);
332 CDS_INIT_LIST_HEAD(&event
->enablers_ref_head
);
334 /* Populate lttng_event structure before tracepoint registration. */
336 ret
= __tracepoint_probe_register(event_name
,
337 desc
->probe_callback
,
338 event
, desc
->signature
);
341 event
->id
= chan
->free_event_id
++;
342 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
, event
);
344 goto statedump_error
;
345 cds_list_add(&event
->node
, &chan
->session
->events_head
);
346 cds_hlist_add_head(&event
->hlist
, head
);
350 WARN_ON_ONCE(__tracepoint_probe_unregister(event_name
,
351 desc
->probe_callback
,
362 int lttng_desc_match_wildcard_enabler(const struct lttng_event_desc
*desc
,
363 struct lttng_enabler
*enabler
)
366 unsigned int has_loglevel
;
368 assert(enabler
->type
== LTTNG_ENABLER_WILDCARD
);
369 /* Compare excluding final '*' */
370 if (strncmp(desc
->name
, enabler
->event_param
.name
,
371 strlen(enabler
->event_param
.name
) - 1))
373 if (desc
->loglevel
) {
374 loglevel
= *(*desc
->loglevel
);
377 if (!lttng_loglevel_match(loglevel
,
379 enabler
->event_param
.loglevel_type
,
380 enabler
->event_param
.loglevel
))
386 int lttng_desc_match_event_enabler(const struct lttng_event_desc
*desc
,
387 struct lttng_enabler
*enabler
)
390 unsigned int has_loglevel
= 0;
392 assert(enabler
->type
== LTTNG_ENABLER_EVENT
);
393 if (strcmp(desc
->name
, enabler
->event_param
.name
))
395 if (desc
->loglevel
) {
396 loglevel
= *(*desc
->loglevel
);
399 if (!lttng_loglevel_match(loglevel
,
401 enabler
->event_param
.loglevel_type
,
402 enabler
->event_param
.loglevel
))
408 int lttng_desc_match_enabler(const struct lttng_event_desc
*desc
,
409 struct lttng_enabler
*enabler
)
411 switch (enabler
->type
) {
412 case LTTNG_ENABLER_WILDCARD
:
413 return lttng_desc_match_wildcard_enabler(desc
, enabler
);
414 case LTTNG_ENABLER_EVENT
:
415 return lttng_desc_match_event_enabler(desc
, enabler
);
422 int lttng_event_match_enabler(struct lttng_event
*event
,
423 struct lttng_enabler
*enabler
)
425 return lttng_desc_match_enabler(event
->desc
, enabler
);
429 struct lttng_enabler_ref
* lttng_event_enabler_ref(struct lttng_event
*event
,
430 struct lttng_enabler
*enabler
)
432 struct lttng_enabler_ref
*enabler_ref
;
434 cds_list_for_each_entry(enabler_ref
,
435 &event
->enablers_ref_head
, node
) {
436 if (enabler_ref
->ref
== enabler
)
443 * Create struct lttng_event if it is missing and present in the list of
447 void lttng_create_event_if_missing(struct lttng_enabler
*enabler
)
449 struct lttng_session
*session
= enabler
->chan
->session
;
450 struct lttng_probe_desc
*probe_desc
;
451 const struct lttng_event_desc
*desc
;
452 struct lttng_event
*event
;
454 struct cds_list_head
*probe_list
;
456 probe_list
= lttng_get_probe_list_head();
458 * For each probe event, if we find that a probe event matches
459 * our enabler, create an associated lttng_event if not
462 cds_list_for_each_entry(probe_desc
, probe_list
, head
) {
463 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
465 struct cds_hlist_head
*head
;
466 struct cds_hlist_node
*node
;
467 const char *event_name
;
471 desc
= probe_desc
->event_desc
[i
];
472 if (!lttng_desc_match_enabler(desc
, enabler
))
474 event_name
= desc
->name
;
475 name_len
= strlen(event_name
);
478 * Check if already created.
480 hash
= jhash(event_name
, name_len
, 0);
481 head
= &session
->events_ht
.table
[hash
& (LTTNG_UST_EVENT_HT_SIZE
- 1)];
482 cds_hlist_for_each_entry(event
, node
, head
, hlist
) {
483 if (event
->desc
== desc
)
490 * We need to create an event for this
493 ret
= lttng_event_create(probe_desc
->event_desc
[i
],
496 DBG("Unable to create event %s\n",
497 probe_desc
->event_desc
[i
]->name
);
504 * Create events associated with an enabler (if not already present),
505 * and add backward reference from the event to the enabler.
508 int lttng_enabler_ref_events(struct lttng_enabler
*enabler
)
510 struct lttng_session
*session
= enabler
->chan
->session
;
511 struct lttng_event
*event
;
513 /* First ensure that probe events are created for this enabler. */
514 lttng_create_event_if_missing(enabler
);
516 /* For each event matching enabler in session event list. */
517 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
518 struct lttng_enabler_ref
*enabler_ref
;
520 if (!lttng_event_match_enabler(event
, enabler
))
523 enabler_ref
= lttng_event_enabler_ref(event
, enabler
);
526 * If no backward ref, create it.
527 * Add backward ref from event to enabler.
529 enabler_ref
= zmalloc(sizeof(*enabler_ref
));
532 enabler_ref
->ref
= enabler
;
533 cds_list_add(&enabler_ref
->node
,
534 &event
->enablers_ref_head
);
538 * Link filter bytecodes if not linked yet.
540 lttng_enabler_event_link_bytecode(event
, enabler
);
542 /* TODO: merge event context. */
548 * Called at library load: connect the probe on all enablers matching
550 * called with session mutex held.
551 * TODO: currently, for each desc added, we iterate on all event desc
552 * (inefficient). We should create specific code that only target the
555 int lttng_fix_pending_event_desc(const struct lttng_event_desc
*desc
)
557 struct lttng_session
*session
;
559 cds_list_for_each_entry(session
, &sessions
, node
) {
560 lttng_session_lazy_sync_enablers(session
);
566 * Only used internally at session destruction.
568 int _lttng_event_unregister(struct lttng_event
*event
)
570 return __tracepoint_probe_unregister(event
->desc
->name
,
571 event
->desc
->probe_callback
,
576 * Only used internally at session destruction.
579 void _lttng_event_destroy(struct lttng_event
*event
)
581 struct lttng_enabler_ref
*enabler_ref
, *tmp_enabler_ref
;
583 cds_list_del(&event
->node
);
584 lttng_destroy_context(event
->ctx
);
585 lttng_free_event_filter_runtime(event
);
586 /* Free event enabler refs */
587 cds_list_for_each_entry_safe(enabler_ref
, tmp_enabler_ref
,
588 &event
->enablers_ref_head
, node
)
594 * We have exclusive access to our metadata buffer (protected by the
595 * ust_lock), so we can do racy operations such as looking for
596 * remaining space left in packet and write, since mutual exclusion
597 * protects us from concurrent writes.
599 int lttng_metadata_printf(struct lttng_session
*session
,
600 const char *fmt
, ...)
602 struct lttng_ust_lib_ring_buffer_ctx ctx
;
603 struct lttng_channel
*chan
= session
->metadata
;
605 int ret
= 0, waitret
;
606 size_t len
, reserve_len
, pos
;
609 WARN_ON_ONCE(!CMM_ACCESS_ONCE(session
->active
));
612 ret
= vasprintf(&str
, fmt
, ap
);
620 for (pos
= 0; pos
< len
; pos
+= reserve_len
) {
621 reserve_len
= min_t(size_t,
622 chan
->ops
->packet_avail_size(chan
->chan
, chan
->handle
),
624 lib_ring_buffer_ctx_init(&ctx
, chan
->chan
, NULL
, reserve_len
,
625 sizeof(char), -1, chan
->handle
);
627 * We don't care about metadata buffer's records lost
628 * count, because we always retry here. Report error if
629 * we need to bail out after timeout or being
632 waitret
= wait_cond_interruptible_timeout(
634 ret
= chan
->ops
->event_reserve(&ctx
, 0);
635 ret
!= -ENOBUFS
|| !ret
;
637 LTTNG_METADATA_TIMEOUT_MSEC
);
638 if (waitret
== -ETIMEDOUT
|| waitret
== -EINTR
|| ret
) {
639 DBG("LTTng: Failure to write metadata to buffers (%s)\n",
640 waitret
== -EINTR
? "interrupted" :
641 (ret
== -ENOBUFS
? "timeout" : "I/O error"));
642 if (waitret
== -EINTR
)
646 chan
->ops
->event_write(&ctx
, &str
[pos
], reserve_len
);
647 chan
->ops
->event_commit(&ctx
);
655 int _lttng_field_statedump(struct lttng_session
*session
,
656 const struct lttng_event_field
*field
)
663 switch (field
->type
.atype
) {
665 ret
= lttng_metadata_printf(session
,
666 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
667 field
->type
.u
.basic
.integer
.size
,
668 field
->type
.u
.basic
.integer
.alignment
,
669 field
->type
.u
.basic
.integer
.signedness
,
670 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
672 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
675 field
->type
.u
.basic
.integer
.base
,
676 #if (BYTE_ORDER == BIG_ENDIAN)
677 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
679 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
684 ret
= lttng_metadata_printf(session
,
685 " floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
686 field
->type
.u
.basic
._float
.exp_dig
,
687 field
->type
.u
.basic
._float
.mant_dig
,
688 field
->type
.u
.basic
._float
.alignment
,
689 #if (BYTE_ORDER == BIG_ENDIAN)
690 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
692 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
697 ret
= lttng_metadata_printf(session
,
699 field
->type
.u
.basic
.enumeration
.name
,
704 const struct lttng_basic_type
*elem_type
;
706 elem_type
= &field
->type
.u
.array
.elem_type
;
707 ret
= lttng_metadata_printf(session
,
708 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
709 elem_type
->u
.basic
.integer
.size
,
710 elem_type
->u
.basic
.integer
.alignment
,
711 elem_type
->u
.basic
.integer
.signedness
,
712 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
714 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
717 elem_type
->u
.basic
.integer
.base
,
718 #if (BYTE_ORDER == BIG_ENDIAN)
719 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
721 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
723 field
->name
, field
->type
.u
.array
.length
);
728 const struct lttng_basic_type
*elem_type
;
729 const struct lttng_basic_type
*length_type
;
731 elem_type
= &field
->type
.u
.sequence
.elem_type
;
732 length_type
= &field
->type
.u
.sequence
.length_type
;
733 ret
= lttng_metadata_printf(session
,
734 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
735 length_type
->u
.basic
.integer
.size
,
736 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
737 length_type
->u
.basic
.integer
.signedness
,
738 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
740 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
743 length_type
->u
.basic
.integer
.base
,
744 #if (BYTE_ORDER == BIG_ENDIAN)
745 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
747 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
753 ret
= lttng_metadata_printf(session
,
754 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
755 elem_type
->u
.basic
.integer
.size
,
756 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
757 elem_type
->u
.basic
.integer
.signedness
,
758 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
760 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
763 elem_type
->u
.basic
.integer
.base
,
764 #if (BYTE_ORDER == BIG_ENDIAN)
765 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
767 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
775 /* Default encoding is UTF8 */
776 ret
= lttng_metadata_printf(session
,
778 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
779 " { encoding = ASCII; }" : "",
790 int _lttng_context_metadata_statedump(struct lttng_session
*session
,
791 struct lttng_ctx
*ctx
)
798 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
799 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
801 ret
= _lttng_field_statedump(session
, &field
->event_field
);
809 int _lttng_fields_metadata_statedump(struct lttng_session
*session
,
810 struct lttng_event
*event
)
812 const struct lttng_event_desc
*desc
= event
->desc
;
816 for (i
= 0; i
< desc
->nr_fields
; i
++) {
817 const struct lttng_event_field
*field
= &desc
->fields
[i
];
819 ret
= _lttng_field_statedump(session
, field
);
827 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
828 struct lttng_channel
*chan
,
829 struct lttng_event
*event
)
832 int loglevel
= TRACE_DEFAULT
;
834 if (event
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
836 if (chan
== session
->metadata
)
839 * Don't print events for which probe load is pending.
844 ret
= lttng_metadata_printf(session
,
848 " stream_id = %u;\n",
855 if (event
->desc
->loglevel
)
856 loglevel
= *(*event
->desc
->loglevel
);
858 ret
= lttng_metadata_printf(session
,
864 if (event
->desc
->u
.ext
.model_emf_uri
) {
865 ret
= lttng_metadata_printf(session
,
866 " model.emf.uri = \"%s\";\n",
867 *(event
->desc
->u
.ext
.model_emf_uri
));
873 ret
= lttng_metadata_printf(session
,
874 " context := struct {\n");
878 ret
= _lttng_context_metadata_statedump(session
, event
->ctx
);
882 ret
= lttng_metadata_printf(session
,
888 ret
= lttng_metadata_printf(session
,
889 " fields := struct {\n"
894 ret
= _lttng_fields_metadata_statedump(session
, event
);
899 * LTTng space reservation can only reserve multiples of the
902 ret
= lttng_metadata_printf(session
,
908 event
->metadata_dumped
= 1;
915 int _lttng_channel_metadata_statedump(struct lttng_session
*session
,
916 struct lttng_channel
*chan
)
920 if (chan
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
922 if (chan
== session
->metadata
)
925 WARN_ON_ONCE(!chan
->header_type
);
926 ret
= lttng_metadata_printf(session
,
929 " event.header := %s;\n"
930 " packet.context := struct packet_context;\n",
932 chan
->header_type
== 1 ? "struct event_header_compact" :
933 "struct event_header_large");
938 ret
= lttng_metadata_printf(session
,
939 " event.context := struct {\n");
943 ret
= _lttng_context_metadata_statedump(session
, chan
->ctx
);
947 ret
= lttng_metadata_printf(session
,
953 ret
= lttng_metadata_printf(session
,
956 chan
->metadata_dumped
= 1;
962 int _lttng_stream_packet_context_declare(struct lttng_session
*session
)
964 return lttng_metadata_printf(session
,
965 "struct packet_context {\n"
966 " uint64_clock_monotonic_t timestamp_begin;\n"
967 " uint64_clock_monotonic_t timestamp_end;\n"
968 " uint64_t content_size;\n"
969 " uint64_t packet_size;\n"
970 " unsigned long events_discarded;\n"
971 " uint32_t cpu_id;\n"
979 * id 31 is reserved to indicate an extended header.
982 * id: range: 0 - 65534.
983 * id 65535 is reserved to indicate an extended header.
986 int _lttng_event_header_declare(struct lttng_session
*session
)
988 return lttng_metadata_printf(session
,
989 "struct event_header_compact {\n"
990 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
993 " uint27_clock_monotonic_t timestamp;\n"
997 " uint64_clock_monotonic_t timestamp;\n"
1002 "struct event_header_large {\n"
1003 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
1006 " uint32_clock_monotonic_t timestamp;\n"
1010 " uint64_clock_monotonic_t timestamp;\n"
1014 lttng_alignof(uint32_t) * CHAR_BIT
,
1015 lttng_alignof(uint16_t) * CHAR_BIT
1020 * Approximation of NTP time of day to clock monotonic correlation,
1021 * taken at start of trace.
1022 * Yes, this is only an approximation. Yes, we can (and will) do better
1023 * in future versions.
1026 uint64_t measure_clock_offset(void)
1028 uint64_t offset
, monotonic
[2], realtime
;
1029 struct timespec rts
= { 0, 0 };
1032 monotonic
[0] = trace_clock_read64();
1033 ret
= clock_gettime(CLOCK_REALTIME
, &rts
);
1036 monotonic
[1] = trace_clock_read64();
1037 offset
= (monotonic
[0] + monotonic
[1]) >> 1;
1038 realtime
= (uint64_t) rts
.tv_sec
* 1000000000ULL;
1039 realtime
+= rts
.tv_nsec
;
1040 offset
= realtime
- offset
;
1045 * Output metadata into this session's metadata buffers.
1048 int _lttng_session_metadata_statedump(struct lttng_session
*session
)
1050 unsigned char *uuid_c
;
1051 char uuid_s
[LTTNG_UST_UUID_STR_LEN
],
1052 clock_uuid_s
[LTTNG_UST_UUID_STR_LEN
];
1053 struct lttng_channel
*chan
;
1054 struct lttng_event
*event
;
1056 char procname
[LTTNG_UST_PROCNAME_LEN
] = "";
1057 char hostname
[HOST_NAME_MAX
];
1059 if (!CMM_ACCESS_ONCE(session
->active
))
1061 if (session
->metadata_dumped
)
1063 if (!session
->metadata
) {
1064 DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n");
1067 uuid_c
= session
->metadata
->uuid
;
1069 snprintf(uuid_s
, sizeof(uuid_s
),
1070 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
1071 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
1072 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
1073 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
1074 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
1076 ret
= lttng_metadata_printf(session
,
1077 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
1078 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
1079 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
1080 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
1081 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
1082 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
1083 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
1089 " byte_order = %s;\n"
1090 " packet.header := struct {\n"
1091 " uint32_t magic;\n"
1092 " uint8_t uuid[16];\n"
1093 " uint32_t stream_id;\n"
1096 lttng_alignof(uint8_t) * CHAR_BIT
,
1097 lttng_alignof(uint16_t) * CHAR_BIT
,
1098 lttng_alignof(uint32_t) * CHAR_BIT
,
1099 lttng_alignof(uint64_t) * CHAR_BIT
,
1100 sizeof(unsigned long) * CHAR_BIT
,
1101 lttng_alignof(unsigned long) * CHAR_BIT
,
1105 #if (BYTE_ORDER == BIG_ENDIAN)
1114 /* ignore error, just use empty string if error. */
1116 ret
= gethostname(hostname
, sizeof(hostname
));
1117 if (ret
&& errno
== ENAMETOOLONG
)
1118 hostname
[HOST_NAME_MAX
- 1] = '\0';
1119 lttng_ust_getprocname(procname
);
1120 procname
[LTTNG_UST_PROCNAME_LEN
- 1] = '\0';
1121 ret
= lttng_metadata_printf(session
,
1123 " hostname = \"%s\";\n"
1125 " procname = \"%s\";\n"
1126 " domain = \"ust\";\n"
1127 " tracer_name = \"lttng-ust\";\n"
1128 " tracer_major = %u;\n"
1129 " tracer_minor = %u;\n"
1130 " tracer_patchlevel = %u;\n"
1135 LTTNG_UST_MAJOR_VERSION
,
1136 LTTNG_UST_MINOR_VERSION
,
1137 LTTNG_UST_PATCHLEVEL_VERSION
1142 ret
= lttng_metadata_printf(session
,
1150 if (!trace_clock_uuid(clock_uuid_s
)) {
1151 ret
= lttng_metadata_printf(session
,
1152 " uuid = \"%s\";\n",
1159 ret
= lttng_metadata_printf(session
,
1160 " description = \"Monotonic Clock\";\n"
1161 " freq = %" PRIu64
"; /* Frequency, in Hz */\n"
1162 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
1163 " offset = %" PRIu64
";\n"
1166 measure_clock_offset()
1171 ret
= lttng_metadata_printf(session
,
1172 "typealias integer {\n"
1173 " size = 27; align = 1; signed = false;\n"
1174 " map = clock.monotonic.value;\n"
1175 "} := uint27_clock_monotonic_t;\n"
1177 "typealias integer {\n"
1178 " size = 32; align = %u; signed = false;\n"
1179 " map = clock.monotonic.value;\n"
1180 "} := uint32_clock_monotonic_t;\n"
1182 "typealias integer {\n"
1183 " size = 64; align = %u; signed = false;\n"
1184 " map = clock.monotonic.value;\n"
1185 "} := uint64_clock_monotonic_t;\n\n",
1186 lttng_alignof(uint32_t) * CHAR_BIT
,
1187 lttng_alignof(uint64_t) * CHAR_BIT
1192 ret
= _lttng_stream_packet_context_declare(session
);
1196 ret
= _lttng_event_header_declare(session
);
1201 cds_list_for_each_entry(chan
, &session
->chan_head
, node
) {
1202 ret
= _lttng_channel_metadata_statedump(session
, chan
);
1207 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
1208 ret
= _lttng_event_metadata_statedump(session
, event
->chan
, event
);
1212 session
->metadata_dumped
= 1;
1217 void lttng_ust_events_exit(void)
1219 struct lttng_session
*session
, *tmpsession
;
1221 cds_list_for_each_entry_safe(session
, tmpsession
, &sessions
, node
)
1222 lttng_session_destroy(session
);
1226 * Enabler management.
1228 struct lttng_enabler
*lttng_enabler_create(enum lttng_enabler_type type
,
1229 struct lttng_ust_event
*event_param
,
1230 struct lttng_channel
*chan
)
1232 struct lttng_enabler
*enabler
;
1234 enabler
= zmalloc(sizeof(*enabler
));
1237 enabler
->type
= type
;
1238 CDS_INIT_LIST_HEAD(&enabler
->filter_bytecode_head
);
1239 memcpy(&enabler
->event_param
, event_param
,
1240 sizeof(enabler
->event_param
));
1241 enabler
->chan
= chan
;
1243 enabler
->enabled
= 1;
1244 cds_list_add(&enabler
->node
, &enabler
->chan
->session
->enablers_head
);
1245 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1249 int lttng_enabler_enable(struct lttng_enabler
*enabler
)
1251 enabler
->enabled
= 1;
1252 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1256 int lttng_enabler_disable(struct lttng_enabler
*enabler
)
1258 if (enabler
->chan
== enabler
->chan
->session
->metadata
)
1260 enabler
->enabled
= 0;
1261 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1265 int lttng_enabler_attach_bytecode(struct lttng_enabler
*enabler
,
1266 struct lttng_ust_filter_bytecode_node
*bytecode
)
1268 bytecode
->enabler
= enabler
;
1269 cds_list_add_tail(&bytecode
->node
, &enabler
->filter_bytecode_head
);
1270 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1274 int lttng_attach_context(struct lttng_ust_context
*context_param
,
1275 struct lttng_ctx
**ctx
, struct lttng_session
*session
)
1278 * We cannot attach a context after trace has been started for a
1279 * session because the metadata does not allow expressing this
1280 * information outside of the original channel scope.
1282 if (session
->been_active
)
1285 switch (context_param
->ctx
) {
1286 case LTTNG_UST_CONTEXT_PTHREAD_ID
:
1287 return lttng_add_pthread_id_to_ctx(ctx
);
1288 case LTTNG_UST_CONTEXT_VTID
:
1289 return lttng_add_vtid_to_ctx(ctx
);
1290 case LTTNG_UST_CONTEXT_VPID
:
1291 return lttng_add_vpid_to_ctx(ctx
);
1292 case LTTNG_UST_CONTEXT_PROCNAME
:
1293 return lttng_add_procname_to_ctx(ctx
);
1299 int lttng_enabler_attach_context(struct lttng_enabler
*enabler
,
1300 struct lttng_ust_context
*context_param
)
1302 #if 0 // disabled for now.
1303 struct lttng_session
*session
= enabler
->chan
->session
;
1306 ret
= lttng_attach_context(context_param
, &enabler
->ctx
,
1310 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1316 void lttng_enabler_destroy(struct lttng_enabler
*enabler
)
1318 struct lttng_ust_filter_bytecode_node
*filter_node
, *tmp_filter_node
;
1320 /* Destroy filter bytecode */
1321 cds_list_for_each_entry_safe(filter_node
, tmp_filter_node
,
1322 &enabler
->filter_bytecode_head
, node
) {
1326 /* Destroy contexts */
1327 lttng_destroy_context(enabler
->ctx
);
1329 cds_list_del(&enabler
->node
);
1334 * lttng_session_sync_enablers should be called just before starting a
1338 void lttng_session_sync_enablers(struct lttng_session
*session
)
1340 struct lttng_enabler
*enabler
;
1341 struct lttng_event
*event
;
1343 cds_list_for_each_entry(enabler
, &session
->enablers_head
, node
)
1344 lttng_enabler_ref_events(enabler
);
1346 * For each event, if at least one of its enablers is enabled,
1347 * we enable the event, else we disable it.
1349 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
1350 struct lttng_enabler_ref
*enabler_ref
;
1351 struct lttng_bytecode_runtime
*runtime
;
1352 int enabled
= 0, has_enablers_without_bytecode
= 0;
1355 cds_list_for_each_entry(enabler_ref
,
1356 &event
->enablers_ref_head
, node
) {
1357 if (enabler_ref
->ref
->enabled
) {
1362 event
->enabled
= enabled
;
1364 /* Check if has enablers without bytecode enabled */
1365 cds_list_for_each_entry(enabler_ref
,
1366 &event
->enablers_ref_head
, node
) {
1367 if (enabler_ref
->ref
->enabled
1368 && cds_list_empty(&enabler_ref
->ref
->filter_bytecode_head
)) {
1369 has_enablers_without_bytecode
= 1;
1373 event
->has_enablers_without_bytecode
=
1374 has_enablers_without_bytecode
;
1376 /* Enable filters */
1377 cds_list_for_each_entry(runtime
,
1378 &event
->bytecode_runtime_head
, node
) {
1379 lttng_filter_sync_state(runtime
);
1385 * Apply enablers to session events, adding events to session if need
1386 * be. It is required after each modification applied to an active
1387 * session, and right before session "start".
1388 * "lazy" sync means we only sync if required.
1391 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
)
1393 /* We can skip if session is not active */
1394 if (!session
->active
)
1396 lttng_session_sync_enablers(session
);