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>
52 #include "lttng-ust-uuid.h"
54 #include "tracepoint-internal.h"
55 #include "lttng-tracer.h"
56 #include "lttng-tracer-core.h"
58 #include "../libringbuffer/shm.h"
62 * The sessions mutex is the centralized mutex across UST tracing
63 * control and probe registration. All operations within this file are
64 * called by the communication thread, under ust_lock protection.
66 static pthread_mutex_t sessions_mutex
= PTHREAD_MUTEX_INITIALIZER
;
70 pthread_mutex_lock(&sessions_mutex
);
75 pthread_mutex_unlock(&sessions_mutex
);
78 static CDS_LIST_HEAD(sessions
);
80 static void _lttng_event_destroy(struct lttng_event
*event
);
81 static int _lttng_event_unregister(struct lttng_event
*event
);
83 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
84 struct lttng_channel
*chan
,
85 struct lttng_event
*event
);
87 int _lttng_session_metadata_statedump(struct lttng_session
*session
);
90 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
);
92 void lttng_session_sync_enablers(struct lttng_session
*session
);
94 void lttng_enabler_destroy(struct lttng_enabler
*enabler
);
97 * Called with ust lock held.
99 int lttng_session_active(void)
101 struct lttng_session
*iter
;
103 cds_list_for_each_entry(iter
, &sessions
, node
) {
111 int lttng_loglevel_match(int loglevel
,
112 unsigned int has_loglevel
,
113 enum lttng_ust_loglevel_type req_type
,
116 if (req_type
== LTTNG_UST_LOGLEVEL_ALL
)
119 loglevel
= TRACE_DEFAULT
;
121 case LTTNG_UST_LOGLEVEL_RANGE
:
122 if (loglevel
<= req_loglevel
|| req_loglevel
== -1)
126 case LTTNG_UST_LOGLEVEL_SINGLE
:
127 if (loglevel
== req_loglevel
|| req_loglevel
== -1)
131 case LTTNG_UST_LOGLEVEL_ALL
:
137 void synchronize_trace(void)
142 struct lttng_session
*lttng_session_create(void)
144 struct lttng_session
*session
;
147 session
= zmalloc(sizeof(struct lttng_session
));
150 CDS_INIT_LIST_HEAD(&session
->chan_head
);
151 CDS_INIT_LIST_HEAD(&session
->events_head
);
152 CDS_INIT_LIST_HEAD(&session
->enablers_head
);
153 for (i
= 0; i
< LTTNG_UST_EVENT_HT_SIZE
; i
++)
154 CDS_INIT_HLIST_HEAD(&session
->events_ht
.table
[i
]);
155 cds_list_add(&session
->node
, &sessions
);
160 * Only used internally at session destruction.
163 void _lttng_channel_unmap(struct lttng_channel
*lttng_chan
)
165 struct channel
*chan
;
166 struct lttng_ust_shm_handle
*handle
;
168 cds_list_del(<tng_chan
->node
);
169 lttng_destroy_context(lttng_chan
->ctx
);
170 chan
= lttng_chan
->chan
;
171 handle
= lttng_chan
->handle
;
173 * note: lttng_chan is private data contained within handle. It
174 * will be freed along with the handle.
176 channel_destroy(chan
, handle
, 0);
179 void lttng_session_destroy(struct lttng_session
*session
)
181 struct lttng_channel
*chan
, *tmpchan
;
182 struct lttng_event
*event
, *tmpevent
;
183 struct lttng_enabler
*enabler
, *tmpenabler
;
186 CMM_ACCESS_ONCE(session
->active
) = 0;
187 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
188 ret
= _lttng_event_unregister(event
);
191 synchronize_trace(); /* Wait for in-flight events to complete */
192 cds_list_for_each_entry_safe(enabler
, tmpenabler
,
193 &session
->enablers_head
, node
)
194 lttng_enabler_destroy(enabler
);
195 cds_list_for_each_entry_safe(event
, tmpevent
,
196 &session
->events_head
, node
)
197 _lttng_event_destroy(event
);
198 cds_list_for_each_entry_safe(chan
, tmpchan
, &session
->chan_head
, node
)
199 _lttng_channel_unmap(chan
);
200 cds_list_del(&session
->node
);
204 int lttng_session_enable(struct lttng_session
*session
)
207 struct lttng_channel
*chan
;
210 if (session
->active
) {
215 notify_socket
= lttng_get_notify_socket(session
->owner
);
216 if (notify_socket
< 0)
217 return notify_socket
;
219 /* We need to sync enablers with session before activation. */
220 lttng_session_sync_enablers(session
);
223 * Snapshot the number of events per channel to know the type of header
226 cds_list_for_each_entry(chan
, &session
->chan_head
, node
) {
227 const struct lttng_ctx
*ctx
;
228 const struct lttng_event_field
*fields
= NULL
;
229 size_t nr_fields
= 0;
231 /* don't change it if session stop/restart */
232 if (chan
->header_type
)
236 nr_fields
= ctx
->nr_fields
;
237 fields
= &ctx
->fields
->event_field
;
239 ret
= ustcomm_register_channel(notify_socket
,
250 CMM_ACCESS_ONCE(session
->active
) = 1;
251 CMM_ACCESS_ONCE(session
->been_active
) = 1;
256 int lttng_session_disable(struct lttng_session
*session
)
260 if (!session
->active
) {
264 CMM_ACCESS_ONCE(session
->active
) = 0;
269 int lttng_channel_enable(struct lttng_channel
*channel
)
273 if (channel
== channel
->session
->metadata
)
275 old
= uatomic_xchg(&channel
->enabled
, 1);
281 int lttng_channel_disable(struct lttng_channel
*channel
)
285 if (channel
== channel
->session
->metadata
)
287 old
= uatomic_xchg(&channel
->enabled
, 0);
293 int lttng_event_enable(struct lttng_event
*event
)
297 if (event
->chan
== event
->chan
->session
->metadata
)
299 old
= uatomic_xchg(&event
->enabled
, 1);
305 int lttng_event_disable(struct lttng_event
*event
)
309 if (event
->chan
== event
->chan
->session
->metadata
)
311 old
= uatomic_xchg(&event
->enabled
, 0);
318 * Supports event creation while tracing session is active.
321 int lttng_event_create(const struct lttng_event_desc
*desc
,
322 struct lttng_channel
*chan
)
324 const char *event_name
= desc
->name
;
325 struct lttng_event
*event
;
326 struct lttng_session
*session
= chan
->session
;
327 struct cds_hlist_head
*head
;
328 struct cds_hlist_node
*node
;
330 size_t name_len
= strlen(event_name
);
332 int notify_socket
, loglevel
;
335 hash
= jhash(event_name
, name_len
, 0);
336 head
= &chan
->session
->events_ht
.table
[hash
& (LTTNG_UST_EVENT_HT_SIZE
- 1)];
337 cds_hlist_for_each_entry(event
, node
, head
, hlist
) {
339 if (!strncmp(event
->desc
->name
,
341 LTTNG_UST_SYM_NAME_LEN
- 1)) {
347 notify_socket
= lttng_get_notify_socket(session
->owner
);
348 if (notify_socket
< 0) {
354 * Check if loglevel match. Refuse to connect event if not.
356 event
= zmalloc(sizeof(struct lttng_event
));
364 CDS_INIT_LIST_HEAD(&event
->bytecode_runtime_head
);
365 CDS_INIT_LIST_HEAD(&event
->enablers_ref_head
);
369 loglevel
= *(*event
->desc
->loglevel
);
371 loglevel
= TRACE_DEFAULT
;
372 if (desc
->u
.ext
.model_emf_uri
)
373 uri
= *(desc
->u
.ext
.model_emf_uri
);
377 /* Don't register metadata events */
378 if (session
->metadata
== chan
) {
381 /* Fetch event ID from sessiond */
382 ret
= ustcomm_register_event(notify_socket
,
393 goto sessiond_register_error
;
397 /* Populate lttng_event structure before tracepoint registration. */
399 ret
= __tracepoint_probe_register(event_name
,
400 desc
->probe_callback
,
401 event
, desc
->signature
);
403 goto tracepoint_register_error
;
405 cds_list_add(&event
->node
, &chan
->session
->events_head
);
406 cds_hlist_add_head(&event
->hlist
, head
);
409 tracepoint_register_error
:
410 sessiond_register_error
:
419 int lttng_desc_match_wildcard_enabler(const struct lttng_event_desc
*desc
,
420 struct lttng_enabler
*enabler
)
423 unsigned int has_loglevel
;
425 assert(enabler
->type
== LTTNG_ENABLER_WILDCARD
);
426 /* Compare excluding final '*' */
427 if (strncmp(desc
->name
, enabler
->event_param
.name
,
428 strlen(enabler
->event_param
.name
) - 1))
430 if (desc
->loglevel
) {
431 loglevel
= *(*desc
->loglevel
);
434 if (!lttng_loglevel_match(loglevel
,
436 enabler
->event_param
.loglevel_type
,
437 enabler
->event_param
.loglevel
))
443 int lttng_desc_match_event_enabler(const struct lttng_event_desc
*desc
,
444 struct lttng_enabler
*enabler
)
447 unsigned int has_loglevel
= 0;
449 assert(enabler
->type
== LTTNG_ENABLER_EVENT
);
450 if (strcmp(desc
->name
, enabler
->event_param
.name
))
452 if (desc
->loglevel
) {
453 loglevel
= *(*desc
->loglevel
);
456 if (!lttng_loglevel_match(loglevel
,
458 enabler
->event_param
.loglevel_type
,
459 enabler
->event_param
.loglevel
))
465 int lttng_desc_match_enabler(const struct lttng_event_desc
*desc
,
466 struct lttng_enabler
*enabler
)
468 switch (enabler
->type
) {
469 case LTTNG_ENABLER_WILDCARD
:
470 return lttng_desc_match_wildcard_enabler(desc
, enabler
);
471 case LTTNG_ENABLER_EVENT
:
472 return lttng_desc_match_event_enabler(desc
, enabler
);
479 int lttng_event_match_enabler(struct lttng_event
*event
,
480 struct lttng_enabler
*enabler
)
482 return lttng_desc_match_enabler(event
->desc
, enabler
);
486 struct lttng_enabler_ref
* lttng_event_enabler_ref(struct lttng_event
*event
,
487 struct lttng_enabler
*enabler
)
489 struct lttng_enabler_ref
*enabler_ref
;
491 cds_list_for_each_entry(enabler_ref
,
492 &event
->enablers_ref_head
, node
) {
493 if (enabler_ref
->ref
== enabler
)
500 * Create struct lttng_event if it is missing and present in the list of
504 void lttng_create_event_if_missing(struct lttng_enabler
*enabler
)
506 struct lttng_session
*session
= enabler
->chan
->session
;
507 struct lttng_probe_desc
*probe_desc
;
508 const struct lttng_event_desc
*desc
;
509 struct lttng_event
*event
;
511 struct cds_list_head
*probe_list
;
513 probe_list
= lttng_get_probe_list_head();
515 * For each probe event, if we find that a probe event matches
516 * our enabler, create an associated lttng_event if not
519 cds_list_for_each_entry(probe_desc
, probe_list
, head
) {
520 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
522 struct cds_hlist_head
*head
;
523 struct cds_hlist_node
*node
;
524 const char *event_name
;
528 desc
= probe_desc
->event_desc
[i
];
529 if (!lttng_desc_match_enabler(desc
, enabler
))
531 event_name
= desc
->name
;
532 name_len
= strlen(event_name
);
535 * Check if already created.
537 hash
= jhash(event_name
, name_len
, 0);
538 head
= &session
->events_ht
.table
[hash
& (LTTNG_UST_EVENT_HT_SIZE
- 1)];
539 cds_hlist_for_each_entry(event
, node
, head
, hlist
) {
540 if (event
->desc
== desc
)
547 * We need to create an event for this
550 ret
= lttng_event_create(probe_desc
->event_desc
[i
],
553 DBG("Unable to create event %s, error %d\n",
554 probe_desc
->event_desc
[i
]->name
, ret
);
561 * Create events associated with an enabler (if not already present),
562 * and add backward reference from the event to the enabler.
565 int lttng_enabler_ref_events(struct lttng_enabler
*enabler
)
567 struct lttng_session
*session
= enabler
->chan
->session
;
568 struct lttng_event
*event
;
570 /* First ensure that probe events are created for this enabler. */
571 lttng_create_event_if_missing(enabler
);
573 /* For each event matching enabler in session event list. */
574 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
575 struct lttng_enabler_ref
*enabler_ref
;
577 if (!lttng_event_match_enabler(event
, enabler
))
580 enabler_ref
= lttng_event_enabler_ref(event
, enabler
);
583 * If no backward ref, create it.
584 * Add backward ref from event to enabler.
586 enabler_ref
= zmalloc(sizeof(*enabler_ref
));
589 enabler_ref
->ref
= enabler
;
590 cds_list_add(&enabler_ref
->node
,
591 &event
->enablers_ref_head
);
595 * Link filter bytecodes if not linked yet.
597 lttng_enabler_event_link_bytecode(event
, enabler
);
599 /* TODO: merge event context. */
605 * Called at library load: connect the probe on all enablers matching
607 * called with session mutex held.
608 * TODO: currently, for each desc added, we iterate on all event desc
609 * (inefficient). We should create specific code that only target the
612 int lttng_fix_pending_event_desc(const struct lttng_event_desc
*desc
)
614 struct lttng_session
*session
;
616 cds_list_for_each_entry(session
, &sessions
, node
) {
617 lttng_session_lazy_sync_enablers(session
);
623 * Only used internally at session destruction.
625 int _lttng_event_unregister(struct lttng_event
*event
)
627 return __tracepoint_probe_unregister(event
->desc
->name
,
628 event
->desc
->probe_callback
,
633 * Only used internally at session destruction.
636 void _lttng_event_destroy(struct lttng_event
*event
)
638 struct lttng_enabler_ref
*enabler_ref
, *tmp_enabler_ref
;
640 cds_list_del(&event
->node
);
641 lttng_destroy_context(event
->ctx
);
642 lttng_free_event_filter_runtime(event
);
643 /* Free event enabler refs */
644 cds_list_for_each_entry_safe(enabler_ref
, tmp_enabler_ref
,
645 &event
->enablers_ref_head
, node
)
651 * We have exclusive access to our metadata buffer (protected by the
652 * ust_lock), so we can do racy operations such as looking for
653 * remaining space left in packet and write, since mutual exclusion
654 * protects us from concurrent writes.
656 int lttng_metadata_printf(struct lttng_session
*session
,
657 const char *fmt
, ...)
659 struct lttng_ust_lib_ring_buffer_ctx ctx
;
660 struct lttng_channel
*chan
= session
->metadata
;
662 int ret
= 0, waitret
;
663 size_t len
, reserve_len
, pos
;
666 WARN_ON_ONCE(!CMM_ACCESS_ONCE(session
->active
));
669 ret
= vasprintf(&str
, fmt
, ap
);
677 for (pos
= 0; pos
< len
; pos
+= reserve_len
) {
678 reserve_len
= min_t(size_t,
679 chan
->ops
->packet_avail_size(chan
->chan
, chan
->handle
),
681 lib_ring_buffer_ctx_init(&ctx
, chan
->chan
, NULL
, reserve_len
,
682 sizeof(char), -1, chan
->handle
);
684 * We don't care about metadata buffer's records lost
685 * count, because we always retry here. Report error if
686 * we need to bail out after timeout or being
689 waitret
= wait_cond_interruptible_timeout(
691 ret
= chan
->ops
->event_reserve(&ctx
, 0);
692 ret
!= -ENOBUFS
|| !ret
;
694 LTTNG_METADATA_TIMEOUT_MSEC
);
695 if (waitret
== -ETIMEDOUT
|| waitret
== -EINTR
|| ret
) {
696 DBG("LTTng: Failure to write metadata to buffers (%s)\n",
697 waitret
== -EINTR
? "interrupted" :
698 (ret
== -ENOBUFS
? "timeout" : "I/O error"));
699 if (waitret
== -EINTR
)
703 chan
->ops
->event_write(&ctx
, &str
[pos
], reserve_len
);
704 chan
->ops
->event_commit(&ctx
);
712 int _lttng_field_statedump(struct lttng_session
*session
,
713 const struct lttng_event_field
*field
)
720 switch (field
->type
.atype
) {
722 ret
= lttng_metadata_printf(session
,
723 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
724 field
->type
.u
.basic
.integer
.size
,
725 field
->type
.u
.basic
.integer
.alignment
,
726 field
->type
.u
.basic
.integer
.signedness
,
727 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
729 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
732 field
->type
.u
.basic
.integer
.base
,
733 #if (BYTE_ORDER == BIG_ENDIAN)
734 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
736 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
741 ret
= lttng_metadata_printf(session
,
742 " floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
743 field
->type
.u
.basic
._float
.exp_dig
,
744 field
->type
.u
.basic
._float
.mant_dig
,
745 field
->type
.u
.basic
._float
.alignment
,
746 #if (BYTE_ORDER == BIG_ENDIAN)
747 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
749 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
754 ret
= lttng_metadata_printf(session
,
756 field
->type
.u
.basic
.enumeration
.name
,
761 const struct lttng_basic_type
*elem_type
;
763 elem_type
= &field
->type
.u
.array
.elem_type
;
764 ret
= lttng_metadata_printf(session
,
765 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
766 elem_type
->u
.basic
.integer
.size
,
767 elem_type
->u
.basic
.integer
.alignment
,
768 elem_type
->u
.basic
.integer
.signedness
,
769 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
771 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
774 elem_type
->u
.basic
.integer
.base
,
775 #if (BYTE_ORDER == BIG_ENDIAN)
776 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
778 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
780 field
->name
, field
->type
.u
.array
.length
);
785 const struct lttng_basic_type
*elem_type
;
786 const struct lttng_basic_type
*length_type
;
788 elem_type
= &field
->type
.u
.sequence
.elem_type
;
789 length_type
= &field
->type
.u
.sequence
.length_type
;
790 ret
= lttng_metadata_printf(session
,
791 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
792 length_type
->u
.basic
.integer
.size
,
793 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
794 length_type
->u
.basic
.integer
.signedness
,
795 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
797 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
800 length_type
->u
.basic
.integer
.base
,
801 #if (BYTE_ORDER == BIG_ENDIAN)
802 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
804 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
810 ret
= lttng_metadata_printf(session
,
811 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
812 elem_type
->u
.basic
.integer
.size
,
813 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
814 elem_type
->u
.basic
.integer
.signedness
,
815 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
817 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
820 elem_type
->u
.basic
.integer
.base
,
821 #if (BYTE_ORDER == BIG_ENDIAN)
822 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
824 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
832 /* Default encoding is UTF8 */
833 ret
= lttng_metadata_printf(session
,
835 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
836 " { encoding = ASCII; }" : "",
847 int _lttng_context_metadata_statedump(struct lttng_session
*session
,
848 struct lttng_ctx
*ctx
)
855 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
856 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
858 ret
= _lttng_field_statedump(session
, &field
->event_field
);
866 int _lttng_fields_metadata_statedump(struct lttng_session
*session
,
867 struct lttng_event
*event
)
869 const struct lttng_event_desc
*desc
= event
->desc
;
873 for (i
= 0; i
< desc
->nr_fields
; i
++) {
874 const struct lttng_event_field
*field
= &desc
->fields
[i
];
876 ret
= _lttng_field_statedump(session
, field
);
884 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
885 struct lttng_channel
*chan
,
886 struct lttng_event
*event
)
889 int loglevel
= TRACE_DEFAULT
;
891 if (event
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
893 if (chan
== session
->metadata
)
896 * Don't print events for which probe load is pending.
901 ret
= lttng_metadata_printf(session
,
905 " stream_id = %u;\n",
912 if (event
->desc
->loglevel
)
913 loglevel
= *(*event
->desc
->loglevel
);
915 ret
= lttng_metadata_printf(session
,
921 if (event
->desc
->u
.ext
.model_emf_uri
) {
922 ret
= lttng_metadata_printf(session
,
923 " model.emf.uri = \"%s\";\n",
924 *(event
->desc
->u
.ext
.model_emf_uri
));
930 ret
= lttng_metadata_printf(session
,
931 " context := struct {\n");
935 ret
= _lttng_context_metadata_statedump(session
, event
->ctx
);
939 ret
= lttng_metadata_printf(session
,
945 ret
= lttng_metadata_printf(session
,
946 " fields := struct {\n"
951 ret
= _lttng_fields_metadata_statedump(session
, event
);
956 * LTTng space reservation can only reserve multiples of the
959 ret
= lttng_metadata_printf(session
,
965 event
->metadata_dumped
= 1;
972 int _lttng_channel_metadata_statedump(struct lttng_session
*session
,
973 struct lttng_channel
*chan
)
977 if (chan
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
979 if (chan
== session
->metadata
)
982 WARN_ON_ONCE(!chan
->header_type
);
983 ret
= lttng_metadata_printf(session
,
986 " event.header := %s;\n"
987 " packet.context := struct packet_context;\n",
989 chan
->header_type
== 1 ? "struct event_header_compact" :
990 "struct event_header_large");
995 ret
= lttng_metadata_printf(session
,
996 " event.context := struct {\n");
1000 ret
= _lttng_context_metadata_statedump(session
, chan
->ctx
);
1004 ret
= lttng_metadata_printf(session
,
1010 ret
= lttng_metadata_printf(session
,
1013 chan
->metadata_dumped
= 1;
1019 int _lttng_stream_packet_context_declare(struct lttng_session
*session
)
1021 return lttng_metadata_printf(session
,
1022 "struct packet_context {\n"
1023 " uint64_clock_monotonic_t timestamp_begin;\n"
1024 " uint64_clock_monotonic_t timestamp_end;\n"
1025 " uint64_t content_size;\n"
1026 " uint64_t packet_size;\n"
1027 " unsigned long events_discarded;\n"
1028 " uint32_t cpu_id;\n"
1035 * id: range: 0 - 30.
1036 * id 31 is reserved to indicate an extended header.
1039 * id: range: 0 - 65534.
1040 * id 65535 is reserved to indicate an extended header.
1043 int _lttng_event_header_declare(struct lttng_session
*session
)
1045 return lttng_metadata_printf(session
,
1046 "struct event_header_compact {\n"
1047 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
1050 " uint27_clock_monotonic_t timestamp;\n"
1054 " uint64_clock_monotonic_t timestamp;\n"
1059 "struct event_header_large {\n"
1060 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
1063 " uint32_clock_monotonic_t timestamp;\n"
1067 " uint64_clock_monotonic_t timestamp;\n"
1071 lttng_alignof(uint32_t) * CHAR_BIT
,
1072 lttng_alignof(uint16_t) * CHAR_BIT
1077 * Approximation of NTP time of day to clock monotonic correlation,
1078 * taken at start of trace.
1079 * Yes, this is only an approximation. Yes, we can (and will) do better
1080 * in future versions.
1083 uint64_t measure_clock_offset(void)
1085 uint64_t offset
, monotonic
[2], realtime
;
1086 struct timespec rts
= { 0, 0 };
1089 monotonic
[0] = trace_clock_read64();
1090 ret
= clock_gettime(CLOCK_REALTIME
, &rts
);
1093 monotonic
[1] = trace_clock_read64();
1094 offset
= (monotonic
[0] + monotonic
[1]) >> 1;
1095 realtime
= (uint64_t) rts
.tv_sec
* 1000000000ULL;
1096 realtime
+= rts
.tv_nsec
;
1097 offset
= realtime
- offset
;
1102 * Output metadata into this session's metadata buffers.
1105 int _lttng_session_metadata_statedump(struct lttng_session
*session
)
1107 unsigned char *uuid_c
;
1108 char uuid_s
[LTTNG_UST_UUID_STR_LEN
],
1109 clock_uuid_s
[LTTNG_UST_UUID_STR_LEN
];
1110 struct lttng_channel
*chan
;
1111 struct lttng_event
*event
;
1113 char procname
[LTTNG_UST_PROCNAME_LEN
] = "";
1114 char hostname
[HOST_NAME_MAX
];
1116 if (!CMM_ACCESS_ONCE(session
->active
))
1118 if (session
->metadata_dumped
)
1120 if (!session
->metadata
) {
1121 DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n");
1124 uuid_c
= session
->metadata
->uuid
;
1126 snprintf(uuid_s
, sizeof(uuid_s
),
1127 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
1128 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
1129 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
1130 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
1131 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
1133 ret
= lttng_metadata_printf(session
,
1134 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
1135 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
1136 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
1137 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
1138 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
1139 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
1140 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
1146 " byte_order = %s;\n"
1147 " packet.header := struct {\n"
1148 " uint32_t magic;\n"
1149 " uint8_t uuid[16];\n"
1150 " uint32_t stream_id;\n"
1153 lttng_alignof(uint8_t) * CHAR_BIT
,
1154 lttng_alignof(uint16_t) * CHAR_BIT
,
1155 lttng_alignof(uint32_t) * CHAR_BIT
,
1156 lttng_alignof(uint64_t) * CHAR_BIT
,
1157 sizeof(unsigned long) * CHAR_BIT
,
1158 lttng_alignof(unsigned long) * CHAR_BIT
,
1162 #if (BYTE_ORDER == BIG_ENDIAN)
1171 /* ignore error, just use empty string if error. */
1173 ret
= gethostname(hostname
, sizeof(hostname
));
1174 if (ret
&& errno
== ENAMETOOLONG
)
1175 hostname
[HOST_NAME_MAX
- 1] = '\0';
1176 lttng_ust_getprocname(procname
);
1177 procname
[LTTNG_UST_PROCNAME_LEN
- 1] = '\0';
1178 ret
= lttng_metadata_printf(session
,
1180 " hostname = \"%s\";\n"
1182 " procname = \"%s\";\n"
1183 " domain = \"ust\";\n"
1184 " tracer_name = \"lttng-ust\";\n"
1185 " tracer_major = %u;\n"
1186 " tracer_minor = %u;\n"
1187 " tracer_patchlevel = %u;\n"
1192 LTTNG_UST_MAJOR_VERSION
,
1193 LTTNG_UST_MINOR_VERSION
,
1194 LTTNG_UST_PATCHLEVEL_VERSION
1199 ret
= lttng_metadata_printf(session
,
1207 if (!trace_clock_uuid(clock_uuid_s
)) {
1208 ret
= lttng_metadata_printf(session
,
1209 " uuid = \"%s\";\n",
1216 ret
= lttng_metadata_printf(session
,
1217 " description = \"Monotonic Clock\";\n"
1218 " freq = %" PRIu64
"; /* Frequency, in Hz */\n"
1219 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
1220 " offset = %" PRIu64
";\n"
1223 measure_clock_offset()
1228 ret
= lttng_metadata_printf(session
,
1229 "typealias integer {\n"
1230 " size = 27; align = 1; signed = false;\n"
1231 " map = clock.monotonic.value;\n"
1232 "} := uint27_clock_monotonic_t;\n"
1234 "typealias integer {\n"
1235 " size = 32; align = %u; signed = false;\n"
1236 " map = clock.monotonic.value;\n"
1237 "} := uint32_clock_monotonic_t;\n"
1239 "typealias integer {\n"
1240 " size = 64; align = %u; signed = false;\n"
1241 " map = clock.monotonic.value;\n"
1242 "} := uint64_clock_monotonic_t;\n\n",
1243 lttng_alignof(uint32_t) * CHAR_BIT
,
1244 lttng_alignof(uint64_t) * CHAR_BIT
1249 ret
= _lttng_stream_packet_context_declare(session
);
1253 ret
= _lttng_event_header_declare(session
);
1258 cds_list_for_each_entry(chan
, &session
->chan_head
, node
) {
1259 ret
= _lttng_channel_metadata_statedump(session
, chan
);
1264 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
1265 ret
= _lttng_event_metadata_statedump(session
, event
->chan
, event
);
1269 session
->metadata_dumped
= 1;
1274 void lttng_ust_events_exit(void)
1276 struct lttng_session
*session
, *tmpsession
;
1278 cds_list_for_each_entry_safe(session
, tmpsession
, &sessions
, node
)
1279 lttng_session_destroy(session
);
1283 * Enabler management.
1285 struct lttng_enabler
*lttng_enabler_create(enum lttng_enabler_type type
,
1286 struct lttng_ust_event
*event_param
,
1287 struct lttng_channel
*chan
)
1289 struct lttng_enabler
*enabler
;
1291 enabler
= zmalloc(sizeof(*enabler
));
1294 enabler
->type
= type
;
1295 CDS_INIT_LIST_HEAD(&enabler
->filter_bytecode_head
);
1296 memcpy(&enabler
->event_param
, event_param
,
1297 sizeof(enabler
->event_param
));
1298 enabler
->chan
= chan
;
1300 enabler
->enabled
= 1;
1301 cds_list_add(&enabler
->node
, &enabler
->chan
->session
->enablers_head
);
1302 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1306 int lttng_enabler_enable(struct lttng_enabler
*enabler
)
1308 enabler
->enabled
= 1;
1309 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1313 int lttng_enabler_disable(struct lttng_enabler
*enabler
)
1315 if (enabler
->chan
== enabler
->chan
->session
->metadata
)
1317 enabler
->enabled
= 0;
1318 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1322 int lttng_enabler_attach_bytecode(struct lttng_enabler
*enabler
,
1323 struct lttng_ust_filter_bytecode_node
*bytecode
)
1325 bytecode
->enabler
= enabler
;
1326 cds_list_add_tail(&bytecode
->node
, &enabler
->filter_bytecode_head
);
1327 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1331 int lttng_attach_context(struct lttng_ust_context
*context_param
,
1332 struct lttng_ctx
**ctx
, struct lttng_session
*session
)
1335 * We cannot attach a context after trace has been started for a
1336 * session because the metadata does not allow expressing this
1337 * information outside of the original channel scope.
1339 if (session
->been_active
)
1342 switch (context_param
->ctx
) {
1343 case LTTNG_UST_CONTEXT_PTHREAD_ID
:
1344 return lttng_add_pthread_id_to_ctx(ctx
);
1345 case LTTNG_UST_CONTEXT_VTID
:
1346 return lttng_add_vtid_to_ctx(ctx
);
1347 case LTTNG_UST_CONTEXT_VPID
:
1348 return lttng_add_vpid_to_ctx(ctx
);
1349 case LTTNG_UST_CONTEXT_PROCNAME
:
1350 return lttng_add_procname_to_ctx(ctx
);
1356 int lttng_enabler_attach_context(struct lttng_enabler
*enabler
,
1357 struct lttng_ust_context
*context_param
)
1359 #if 0 // disabled for now.
1360 struct lttng_session
*session
= enabler
->chan
->session
;
1363 ret
= lttng_attach_context(context_param
, &enabler
->ctx
,
1367 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1373 void lttng_enabler_destroy(struct lttng_enabler
*enabler
)
1375 struct lttng_ust_filter_bytecode_node
*filter_node
, *tmp_filter_node
;
1377 /* Destroy filter bytecode */
1378 cds_list_for_each_entry_safe(filter_node
, tmp_filter_node
,
1379 &enabler
->filter_bytecode_head
, node
) {
1383 /* Destroy contexts */
1384 lttng_destroy_context(enabler
->ctx
);
1386 cds_list_del(&enabler
->node
);
1391 * lttng_session_sync_enablers should be called just before starting a
1395 void lttng_session_sync_enablers(struct lttng_session
*session
)
1397 struct lttng_enabler
*enabler
;
1398 struct lttng_event
*event
;
1400 cds_list_for_each_entry(enabler
, &session
->enablers_head
, node
)
1401 lttng_enabler_ref_events(enabler
);
1403 * For each event, if at least one of its enablers is enabled,
1404 * we enable the event, else we disable it.
1406 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
1407 struct lttng_enabler_ref
*enabler_ref
;
1408 struct lttng_bytecode_runtime
*runtime
;
1409 int enabled
= 0, has_enablers_without_bytecode
= 0;
1412 cds_list_for_each_entry(enabler_ref
,
1413 &event
->enablers_ref_head
, node
) {
1414 if (enabler_ref
->ref
->enabled
) {
1419 event
->enabled
= enabled
;
1421 /* Check if has enablers without bytecode enabled */
1422 cds_list_for_each_entry(enabler_ref
,
1423 &event
->enablers_ref_head
, node
) {
1424 if (enabler_ref
->ref
->enabled
1425 && cds_list_empty(&enabler_ref
->ref
->filter_bytecode_head
)) {
1426 has_enablers_without_bytecode
= 1;
1430 event
->has_enablers_without_bytecode
=
1431 has_enablers_without_bytecode
;
1433 /* Enable filters */
1434 cds_list_for_each_entry(runtime
,
1435 &event
->bytecode_runtime_head
, node
) {
1436 lttng_filter_sync_state(runtime
);
1442 * Apply enablers to session events, adding events to session if need
1443 * be. It is required after each modification applied to an active
1444 * session, and right before session "start".
1445 * "lazy" sync means we only sync if required.
1448 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
)
1450 /* We can skip if session is not active */
1451 if (!session
->active
)
1453 lttng_session_sync_enablers(session
);