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 * Called with ust lock held.
97 int lttng_session_active(void)
99 struct lttng_session
*iter
;
101 cds_list_for_each_entry(iter
, &sessions
, node
) {
109 int lttng_loglevel_match(int loglevel
,
110 unsigned int has_loglevel
,
111 enum lttng_ust_loglevel_type req_type
,
114 if (req_type
== LTTNG_UST_LOGLEVEL_ALL
)
117 loglevel
= TRACE_DEFAULT
;
119 case LTTNG_UST_LOGLEVEL_RANGE
:
120 if (loglevel
<= req_loglevel
|| req_loglevel
== -1)
124 case LTTNG_UST_LOGLEVEL_SINGLE
:
125 if (loglevel
== req_loglevel
|| req_loglevel
== -1)
129 case LTTNG_UST_LOGLEVEL_ALL
:
135 void synchronize_trace(void)
140 struct lttng_session
*lttng_session_create(void)
142 struct lttng_session
*session
;
145 session
= zmalloc(sizeof(struct lttng_session
));
148 CDS_INIT_LIST_HEAD(&session
->chan_head
);
149 CDS_INIT_LIST_HEAD(&session
->events_head
);
150 CDS_INIT_LIST_HEAD(&session
->enablers_head
);
151 for (i
= 0; i
< LTTNG_UST_EVENT_HT_SIZE
; i
++)
152 CDS_INIT_HLIST_HEAD(&session
->events_ht
.table
[i
]);
153 cds_list_add(&session
->node
, &sessions
);
158 * Only used internally at session destruction.
161 void _lttng_channel_unmap(struct lttng_channel
*lttng_chan
)
163 struct channel
*chan
;
164 struct lttng_ust_shm_handle
*handle
;
166 cds_list_del(<tng_chan
->node
);
167 lttng_destroy_context(lttng_chan
->ctx
);
168 chan
= lttng_chan
->chan
;
169 handle
= lttng_chan
->handle
;
171 * note: lttng_chan is private data contained within handle. It
172 * will be freed along with the handle.
174 channel_destroy(chan
, handle
, 0);
177 void lttng_session_destroy(struct lttng_session
*session
)
179 struct lttng_channel
*chan
, *tmpchan
;
180 struct lttng_event
*event
, *tmpevent
;
181 struct lttng_enabler
*enabler
, *tmpenabler
;
184 CMM_ACCESS_ONCE(session
->active
) = 0;
185 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
186 ret
= _lttng_event_unregister(event
);
189 synchronize_trace(); /* Wait for in-flight events to complete */
190 cds_list_for_each_entry_safe(enabler
, tmpenabler
,
191 &session
->enablers_head
, node
)
192 lttng_enabler_destroy(enabler
);
193 cds_list_for_each_entry_safe(event
, tmpevent
,
194 &session
->events_head
, node
)
195 _lttng_event_destroy(event
);
196 cds_list_for_each_entry_safe(chan
, tmpchan
, &session
->chan_head
, node
)
197 _lttng_channel_unmap(chan
);
198 cds_list_del(&session
->node
);
202 int lttng_session_enable(struct lttng_session
*session
)
205 struct lttng_channel
*chan
;
207 if (session
->active
) {
212 /* We need to sync enablers with session before activation. */
213 lttng_session_sync_enablers(session
);
216 * Snapshot the number of events per channel to know the type of header
219 cds_list_for_each_entry(chan
, &session
->chan_head
, node
) {
220 if (chan
->header_type
)
221 continue; /* don't change it if session stop/restart */
222 if (chan
->free_event_id
< 31)
223 chan
->header_type
= 1; /* compact */
225 chan
->header_type
= 2; /* large */
228 CMM_ACCESS_ONCE(session
->active
) = 1;
229 CMM_ACCESS_ONCE(session
->been_active
) = 1;
230 ret
= _lttng_session_metadata_statedump(session
);
232 CMM_ACCESS_ONCE(session
->active
) = 0;
237 int lttng_session_disable(struct lttng_session
*session
)
241 if (!session
->active
) {
245 CMM_ACCESS_ONCE(session
->active
) = 0;
250 int lttng_channel_enable(struct lttng_channel
*channel
)
254 if (channel
== channel
->session
->metadata
)
256 old
= uatomic_xchg(&channel
->enabled
, 1);
262 int lttng_channel_disable(struct lttng_channel
*channel
)
266 if (channel
== channel
->session
->metadata
)
268 old
= uatomic_xchg(&channel
->enabled
, 0);
274 int lttng_event_enable(struct lttng_event
*event
)
278 if (event
->chan
== event
->chan
->session
->metadata
)
280 old
= uatomic_xchg(&event
->enabled
, 1);
286 int lttng_event_disable(struct lttng_event
*event
)
290 if (event
->chan
== event
->chan
->session
->metadata
)
292 old
= uatomic_xchg(&event
->enabled
, 0);
299 * Supports event creation while tracing session is active.
302 int lttng_event_create(const struct lttng_event_desc
*desc
,
303 struct lttng_channel
*chan
)
305 const char *event_name
= desc
->name
;
306 struct lttng_event
*event
;
307 struct cds_hlist_head
*head
;
308 struct cds_hlist_node
*node
;
310 size_t name_len
= strlen(event_name
);
313 if (chan
->used_event_id
== -1U) {
317 hash
= jhash(event_name
, name_len
, 0);
318 head
= &chan
->session
->events_ht
.table
[hash
& (LTTNG_UST_EVENT_HT_SIZE
- 1)];
319 cds_hlist_for_each_entry(event
, node
, head
, hlist
) {
321 if (!strncmp(event
->desc
->name
,
323 LTTNG_UST_SYM_NAME_LEN
- 1)) {
330 * Check if loglevel match. Refuse to connect event if not.
332 event
= zmalloc(sizeof(struct lttng_event
));
340 * used_event_id counts the maximum number of event IDs that can
341 * register if all probes register.
343 chan
->used_event_id
++;
345 CDS_INIT_LIST_HEAD(&event
->bytecode_runtime_head
);
346 CDS_INIT_LIST_HEAD(&event
->enablers_ref_head
);
348 /* Populate lttng_event structure before tracepoint registration. */
350 ret
= __tracepoint_probe_register(event_name
,
351 desc
->probe_callback
,
352 event
, desc
->signature
);
355 event
->id
= chan
->free_event_id
++;
356 ret
= _lttng_event_metadata_statedump(chan
->session
, chan
, event
);
358 goto statedump_error
;
359 cds_list_add(&event
->node
, &chan
->session
->events_head
);
360 cds_hlist_add_head(&event
->hlist
, head
);
364 WARN_ON_ONCE(__tracepoint_probe_unregister(event_name
,
365 desc
->probe_callback
,
376 int lttng_desc_match_wildcard_enabler(const struct lttng_event_desc
*desc
,
377 struct lttng_enabler
*enabler
)
380 unsigned int has_loglevel
;
382 assert(enabler
->type
== LTTNG_ENABLER_WILDCARD
);
383 /* Compare excluding final '*' */
384 if (strncmp(desc
->name
, enabler
->event_param
.name
,
385 strlen(enabler
->event_param
.name
) - 1))
387 if (desc
->loglevel
) {
388 loglevel
= *(*desc
->loglevel
);
391 if (!lttng_loglevel_match(loglevel
,
393 enabler
->event_param
.loglevel_type
,
394 enabler
->event_param
.loglevel
))
400 int lttng_desc_match_event_enabler(const struct lttng_event_desc
*desc
,
401 struct lttng_enabler
*enabler
)
404 unsigned int has_loglevel
= 0;
406 assert(enabler
->type
== LTTNG_ENABLER_EVENT
);
407 if (strcmp(desc
->name
, enabler
->event_param
.name
))
409 if (desc
->loglevel
) {
410 loglevel
= *(*desc
->loglevel
);
413 if (!lttng_loglevel_match(loglevel
,
415 enabler
->event_param
.loglevel_type
,
416 enabler
->event_param
.loglevel
))
422 int lttng_desc_match_enabler(const struct lttng_event_desc
*desc
,
423 struct lttng_enabler
*enabler
)
425 switch (enabler
->type
) {
426 case LTTNG_ENABLER_WILDCARD
:
427 return lttng_desc_match_wildcard_enabler(desc
, enabler
);
428 case LTTNG_ENABLER_EVENT
:
429 return lttng_desc_match_event_enabler(desc
, enabler
);
436 int lttng_event_match_enabler(struct lttng_event
*event
,
437 struct lttng_enabler
*enabler
)
439 return lttng_desc_match_enabler(event
->desc
, enabler
);
443 struct lttng_enabler_ref
* lttng_event_enabler_ref(struct lttng_event
*event
,
444 struct lttng_enabler
*enabler
)
446 struct lttng_enabler_ref
*enabler_ref
;
448 cds_list_for_each_entry(enabler_ref
,
449 &event
->enablers_ref_head
, node
) {
450 if (enabler_ref
->ref
== enabler
)
457 * Create struct lttng_event if it is missing and present in the list of
461 void lttng_create_event_if_missing(struct lttng_enabler
*enabler
)
463 struct lttng_session
*session
= enabler
->chan
->session
;
464 struct lttng_probe_desc
*probe_desc
;
465 const struct lttng_event_desc
*desc
;
466 struct lttng_event
*event
;
468 struct cds_list_head
*probe_list
;
470 probe_list
= lttng_get_probe_list_head();
472 * For each probe event, if we find that a probe event matches
473 * our enabler, create an associated lttng_event if not
476 cds_list_for_each_entry(probe_desc
, probe_list
, head
) {
477 for (i
= 0; i
< probe_desc
->nr_events
; i
++) {
479 struct cds_hlist_head
*head
;
480 struct cds_hlist_node
*node
;
481 const char *event_name
;
485 desc
= probe_desc
->event_desc
[i
];
486 if (!lttng_desc_match_enabler(desc
, enabler
))
488 event_name
= desc
->name
;
489 name_len
= strlen(event_name
);
492 * Check if already created.
494 hash
= jhash(event_name
, name_len
, 0);
495 head
= &session
->events_ht
.table
[hash
& (LTTNG_UST_EVENT_HT_SIZE
- 1)];
496 cds_hlist_for_each_entry(event
, node
, head
, hlist
) {
497 if (event
->desc
== desc
)
504 * We need to create an event for this
507 ret
= lttng_event_create(probe_desc
->event_desc
[i
],
510 DBG("Unable to create event %s\n",
511 probe_desc
->event_desc
[i
]->name
);
518 * Create events associated with an enabler (if not already present),
519 * and add backward reference from the event to the enabler.
522 int lttng_enabler_ref_events(struct lttng_enabler
*enabler
)
524 struct lttng_session
*session
= enabler
->chan
->session
;
525 struct lttng_event
*event
;
527 /* First ensure that probe events are created for this enabler. */
528 lttng_create_event_if_missing(enabler
);
530 /* For each event matching enabler in session event list. */
531 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
532 struct lttng_enabler_ref
*enabler_ref
;
534 if (!lttng_event_match_enabler(event
, enabler
))
537 enabler_ref
= lttng_event_enabler_ref(event
, enabler
);
540 * If no backward ref, create it.
541 * Add backward ref from event to enabler.
543 enabler_ref
= zmalloc(sizeof(*enabler_ref
));
546 enabler_ref
->ref
= enabler
;
547 cds_list_add(&enabler_ref
->node
,
548 &event
->enablers_ref_head
);
552 * Link filter bytecodes if not linked yet.
554 lttng_enabler_event_link_bytecode(event
, enabler
);
556 /* TODO: merge event context. */
562 * Called at library load: connect the probe on all enablers matching
564 * called with session mutex held.
565 * TODO: currently, for each desc added, we iterate on all event desc
566 * (inefficient). We should create specific code that only target the
569 int lttng_fix_pending_event_desc(const struct lttng_event_desc
*desc
)
571 struct lttng_session
*session
;
573 cds_list_for_each_entry(session
, &sessions
, node
) {
574 lttng_session_lazy_sync_enablers(session
);
580 * Only used internally at session destruction.
582 int _lttng_event_unregister(struct lttng_event
*event
)
584 return __tracepoint_probe_unregister(event
->desc
->name
,
585 event
->desc
->probe_callback
,
590 * Only used internally at session destruction.
593 void _lttng_event_destroy(struct lttng_event
*event
)
595 struct lttng_enabler_ref
*enabler_ref
, *tmp_enabler_ref
;
597 cds_list_del(&event
->node
);
598 lttng_destroy_context(event
->ctx
);
599 lttng_free_event_filter_runtime(event
);
600 /* Free event enabler refs */
601 cds_list_for_each_entry_safe(enabler_ref
, tmp_enabler_ref
,
602 &event
->enablers_ref_head
, node
)
608 * We have exclusive access to our metadata buffer (protected by the
609 * ust_lock), so we can do racy operations such as looking for
610 * remaining space left in packet and write, since mutual exclusion
611 * protects us from concurrent writes.
613 int lttng_metadata_printf(struct lttng_session
*session
,
614 const char *fmt
, ...)
616 struct lttng_ust_lib_ring_buffer_ctx ctx
;
617 struct lttng_channel
*chan
= session
->metadata
;
619 int ret
= 0, waitret
;
620 size_t len
, reserve_len
, pos
;
623 WARN_ON_ONCE(!CMM_ACCESS_ONCE(session
->active
));
626 ret
= vasprintf(&str
, fmt
, ap
);
634 for (pos
= 0; pos
< len
; pos
+= reserve_len
) {
635 reserve_len
= min_t(size_t,
636 chan
->ops
->packet_avail_size(chan
->chan
, chan
->handle
),
638 lib_ring_buffer_ctx_init(&ctx
, chan
->chan
, NULL
, reserve_len
,
639 sizeof(char), -1, chan
->handle
);
641 * We don't care about metadata buffer's records lost
642 * count, because we always retry here. Report error if
643 * we need to bail out after timeout or being
646 waitret
= wait_cond_interruptible_timeout(
648 ret
= chan
->ops
->event_reserve(&ctx
, 0);
649 ret
!= -ENOBUFS
|| !ret
;
651 LTTNG_METADATA_TIMEOUT_MSEC
);
652 if (waitret
== -ETIMEDOUT
|| waitret
== -EINTR
|| ret
) {
653 DBG("LTTng: Failure to write metadata to buffers (%s)\n",
654 waitret
== -EINTR
? "interrupted" :
655 (ret
== -ENOBUFS
? "timeout" : "I/O error"));
656 if (waitret
== -EINTR
)
660 chan
->ops
->event_write(&ctx
, &str
[pos
], reserve_len
);
661 chan
->ops
->event_commit(&ctx
);
669 int _lttng_field_statedump(struct lttng_session
*session
,
670 const struct lttng_event_field
*field
)
677 switch (field
->type
.atype
) {
679 ret
= lttng_metadata_printf(session
,
680 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
681 field
->type
.u
.basic
.integer
.size
,
682 field
->type
.u
.basic
.integer
.alignment
,
683 field
->type
.u
.basic
.integer
.signedness
,
684 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
686 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
689 field
->type
.u
.basic
.integer
.base
,
690 #if (BYTE_ORDER == BIG_ENDIAN)
691 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
693 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
698 ret
= lttng_metadata_printf(session
,
699 " floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
700 field
->type
.u
.basic
._float
.exp_dig
,
701 field
->type
.u
.basic
._float
.mant_dig
,
702 field
->type
.u
.basic
._float
.alignment
,
703 #if (BYTE_ORDER == BIG_ENDIAN)
704 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
706 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
711 ret
= lttng_metadata_printf(session
,
713 field
->type
.u
.basic
.enumeration
.name
,
718 const struct lttng_basic_type
*elem_type
;
720 elem_type
= &field
->type
.u
.array
.elem_type
;
721 ret
= lttng_metadata_printf(session
,
722 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
723 elem_type
->u
.basic
.integer
.size
,
724 elem_type
->u
.basic
.integer
.alignment
,
725 elem_type
->u
.basic
.integer
.signedness
,
726 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
728 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
731 elem_type
->u
.basic
.integer
.base
,
732 #if (BYTE_ORDER == BIG_ENDIAN)
733 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
735 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
737 field
->name
, field
->type
.u
.array
.length
);
742 const struct lttng_basic_type
*elem_type
;
743 const struct lttng_basic_type
*length_type
;
745 elem_type
= &field
->type
.u
.sequence
.elem_type
;
746 length_type
= &field
->type
.u
.sequence
.length_type
;
747 ret
= lttng_metadata_printf(session
,
748 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
749 length_type
->u
.basic
.integer
.size
,
750 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
751 length_type
->u
.basic
.integer
.signedness
,
752 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
754 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
757 length_type
->u
.basic
.integer
.base
,
758 #if (BYTE_ORDER == BIG_ENDIAN)
759 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
761 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
767 ret
= lttng_metadata_printf(session
,
768 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
769 elem_type
->u
.basic
.integer
.size
,
770 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
771 elem_type
->u
.basic
.integer
.signedness
,
772 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
774 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
777 elem_type
->u
.basic
.integer
.base
,
778 #if (BYTE_ORDER == BIG_ENDIAN)
779 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
781 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
789 /* Default encoding is UTF8 */
790 ret
= lttng_metadata_printf(session
,
792 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
793 " { encoding = ASCII; }" : "",
804 int _lttng_context_metadata_statedump(struct lttng_session
*session
,
805 struct lttng_ctx
*ctx
)
812 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
813 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
815 ret
= _lttng_field_statedump(session
, &field
->event_field
);
823 int _lttng_fields_metadata_statedump(struct lttng_session
*session
,
824 struct lttng_event
*event
)
826 const struct lttng_event_desc
*desc
= event
->desc
;
830 for (i
= 0; i
< desc
->nr_fields
; i
++) {
831 const struct lttng_event_field
*field
= &desc
->fields
[i
];
833 ret
= _lttng_field_statedump(session
, field
);
841 int _lttng_event_metadata_statedump(struct lttng_session
*session
,
842 struct lttng_channel
*chan
,
843 struct lttng_event
*event
)
846 int loglevel
= TRACE_DEFAULT
;
848 if (event
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
850 if (chan
== session
->metadata
)
853 * Don't print events for which probe load is pending.
858 ret
= lttng_metadata_printf(session
,
862 " stream_id = %u;\n",
869 if (event
->desc
->loglevel
)
870 loglevel
= *(*event
->desc
->loglevel
);
872 ret
= lttng_metadata_printf(session
,
878 if (event
->desc
->u
.ext
.model_emf_uri
) {
879 ret
= lttng_metadata_printf(session
,
880 " model.emf.uri = \"%s\";\n",
881 *(event
->desc
->u
.ext
.model_emf_uri
));
887 ret
= lttng_metadata_printf(session
,
888 " context := struct {\n");
892 ret
= _lttng_context_metadata_statedump(session
, event
->ctx
);
896 ret
= lttng_metadata_printf(session
,
902 ret
= lttng_metadata_printf(session
,
903 " fields := struct {\n"
908 ret
= _lttng_fields_metadata_statedump(session
, event
);
913 * LTTng space reservation can only reserve multiples of the
916 ret
= lttng_metadata_printf(session
,
922 event
->metadata_dumped
= 1;
929 int _lttng_channel_metadata_statedump(struct lttng_session
*session
,
930 struct lttng_channel
*chan
)
934 if (chan
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
936 if (chan
== session
->metadata
)
939 WARN_ON_ONCE(!chan
->header_type
);
940 ret
= lttng_metadata_printf(session
,
943 " event.header := %s;\n"
944 " packet.context := struct packet_context;\n",
946 chan
->header_type
== 1 ? "struct event_header_compact" :
947 "struct event_header_large");
952 ret
= lttng_metadata_printf(session
,
953 " event.context := struct {\n");
957 ret
= _lttng_context_metadata_statedump(session
, chan
->ctx
);
961 ret
= lttng_metadata_printf(session
,
967 ret
= lttng_metadata_printf(session
,
970 chan
->metadata_dumped
= 1;
976 int _lttng_stream_packet_context_declare(struct lttng_session
*session
)
978 return lttng_metadata_printf(session
,
979 "struct packet_context {\n"
980 " uint64_clock_monotonic_t timestamp_begin;\n"
981 " uint64_clock_monotonic_t timestamp_end;\n"
982 " uint64_t content_size;\n"
983 " uint64_t packet_size;\n"
984 " unsigned long events_discarded;\n"
985 " uint32_t cpu_id;\n"
993 * id 31 is reserved to indicate an extended header.
996 * id: range: 0 - 65534.
997 * id 65535 is reserved to indicate an extended header.
1000 int _lttng_event_header_declare(struct lttng_session
*session
)
1002 return lttng_metadata_printf(session
,
1003 "struct event_header_compact {\n"
1004 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
1007 " uint27_clock_monotonic_t timestamp;\n"
1011 " uint64_clock_monotonic_t timestamp;\n"
1016 "struct event_header_large {\n"
1017 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
1020 " uint32_clock_monotonic_t timestamp;\n"
1024 " uint64_clock_monotonic_t timestamp;\n"
1028 lttng_alignof(uint32_t) * CHAR_BIT
,
1029 lttng_alignof(uint16_t) * CHAR_BIT
1034 * Approximation of NTP time of day to clock monotonic correlation,
1035 * taken at start of trace.
1036 * Yes, this is only an approximation. Yes, we can (and will) do better
1037 * in future versions.
1040 uint64_t measure_clock_offset(void)
1042 uint64_t offset
, monotonic
[2], realtime
;
1043 struct timespec rts
= { 0, 0 };
1046 monotonic
[0] = trace_clock_read64();
1047 ret
= clock_gettime(CLOCK_REALTIME
, &rts
);
1050 monotonic
[1] = trace_clock_read64();
1051 offset
= (monotonic
[0] + monotonic
[1]) >> 1;
1052 realtime
= (uint64_t) rts
.tv_sec
* 1000000000ULL;
1053 realtime
+= rts
.tv_nsec
;
1054 offset
= realtime
- offset
;
1059 * Output metadata into this session's metadata buffers.
1062 int _lttng_session_metadata_statedump(struct lttng_session
*session
)
1064 unsigned char *uuid_c
;
1065 char uuid_s
[LTTNG_UST_UUID_STR_LEN
],
1066 clock_uuid_s
[LTTNG_UST_UUID_STR_LEN
];
1067 struct lttng_channel
*chan
;
1068 struct lttng_event
*event
;
1070 char procname
[LTTNG_UST_PROCNAME_LEN
] = "";
1071 char hostname
[HOST_NAME_MAX
];
1073 if (!CMM_ACCESS_ONCE(session
->active
))
1075 if (session
->metadata_dumped
)
1077 if (!session
->metadata
) {
1078 DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n");
1081 uuid_c
= session
->metadata
->uuid
;
1083 snprintf(uuid_s
, sizeof(uuid_s
),
1084 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
1085 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
1086 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
1087 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
1088 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
1090 ret
= lttng_metadata_printf(session
,
1091 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
1092 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
1093 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
1094 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
1095 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
1096 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
1097 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
1103 " byte_order = %s;\n"
1104 " packet.header := struct {\n"
1105 " uint32_t magic;\n"
1106 " uint8_t uuid[16];\n"
1107 " uint32_t stream_id;\n"
1110 lttng_alignof(uint8_t) * CHAR_BIT
,
1111 lttng_alignof(uint16_t) * CHAR_BIT
,
1112 lttng_alignof(uint32_t) * CHAR_BIT
,
1113 lttng_alignof(uint64_t) * CHAR_BIT
,
1114 sizeof(unsigned long) * CHAR_BIT
,
1115 lttng_alignof(unsigned long) * CHAR_BIT
,
1119 #if (BYTE_ORDER == BIG_ENDIAN)
1128 /* ignore error, just use empty string if error. */
1130 ret
= gethostname(hostname
, sizeof(hostname
));
1131 if (ret
&& errno
== ENAMETOOLONG
)
1132 hostname
[HOST_NAME_MAX
- 1] = '\0';
1133 lttng_ust_getprocname(procname
);
1134 procname
[LTTNG_UST_PROCNAME_LEN
- 1] = '\0';
1135 ret
= lttng_metadata_printf(session
,
1137 " hostname = \"%s\";\n"
1139 " procname = \"%s\";\n"
1140 " domain = \"ust\";\n"
1141 " tracer_name = \"lttng-ust\";\n"
1142 " tracer_major = %u;\n"
1143 " tracer_minor = %u;\n"
1144 " tracer_patchlevel = %u;\n"
1149 LTTNG_UST_MAJOR_VERSION
,
1150 LTTNG_UST_MINOR_VERSION
,
1151 LTTNG_UST_PATCHLEVEL_VERSION
1156 ret
= lttng_metadata_printf(session
,
1164 if (!trace_clock_uuid(clock_uuid_s
)) {
1165 ret
= lttng_metadata_printf(session
,
1166 " uuid = \"%s\";\n",
1173 ret
= lttng_metadata_printf(session
,
1174 " description = \"Monotonic Clock\";\n"
1175 " freq = %" PRIu64
"; /* Frequency, in Hz */\n"
1176 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
1177 " offset = %" PRIu64
";\n"
1180 measure_clock_offset()
1185 ret
= lttng_metadata_printf(session
,
1186 "typealias integer {\n"
1187 " size = 27; align = 1; signed = false;\n"
1188 " map = clock.monotonic.value;\n"
1189 "} := uint27_clock_monotonic_t;\n"
1191 "typealias integer {\n"
1192 " size = 32; align = %u; signed = false;\n"
1193 " map = clock.monotonic.value;\n"
1194 "} := uint32_clock_monotonic_t;\n"
1196 "typealias integer {\n"
1197 " size = 64; align = %u; signed = false;\n"
1198 " map = clock.monotonic.value;\n"
1199 "} := uint64_clock_monotonic_t;\n\n",
1200 lttng_alignof(uint32_t) * CHAR_BIT
,
1201 lttng_alignof(uint64_t) * CHAR_BIT
1206 ret
= _lttng_stream_packet_context_declare(session
);
1210 ret
= _lttng_event_header_declare(session
);
1215 cds_list_for_each_entry(chan
, &session
->chan_head
, node
) {
1216 ret
= _lttng_channel_metadata_statedump(session
, chan
);
1221 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
1222 ret
= _lttng_event_metadata_statedump(session
, event
->chan
, event
);
1226 session
->metadata_dumped
= 1;
1231 void lttng_ust_events_exit(void)
1233 struct lttng_session
*session
, *tmpsession
;
1235 cds_list_for_each_entry_safe(session
, tmpsession
, &sessions
, node
)
1236 lttng_session_destroy(session
);
1240 * Enabler management.
1242 struct lttng_enabler
*lttng_enabler_create(enum lttng_enabler_type type
,
1243 struct lttng_ust_event
*event_param
,
1244 struct lttng_channel
*chan
)
1246 struct lttng_enabler
*enabler
;
1248 enabler
= zmalloc(sizeof(*enabler
));
1251 enabler
->type
= type
;
1252 CDS_INIT_LIST_HEAD(&enabler
->filter_bytecode_head
);
1253 memcpy(&enabler
->event_param
, event_param
,
1254 sizeof(enabler
->event_param
));
1255 enabler
->chan
= chan
;
1257 enabler
->enabled
= 1;
1258 cds_list_add(&enabler
->node
, &enabler
->chan
->session
->enablers_head
);
1259 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1263 int lttng_enabler_enable(struct lttng_enabler
*enabler
)
1265 enabler
->enabled
= 1;
1266 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1270 int lttng_enabler_disable(struct lttng_enabler
*enabler
)
1272 if (enabler
->chan
== enabler
->chan
->session
->metadata
)
1274 enabler
->enabled
= 0;
1275 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1279 int lttng_enabler_attach_bytecode(struct lttng_enabler
*enabler
,
1280 struct lttng_ust_filter_bytecode_node
*bytecode
)
1282 bytecode
->enabler
= enabler
;
1283 cds_list_add_tail(&bytecode
->node
, &enabler
->filter_bytecode_head
);
1284 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1288 int lttng_attach_context(struct lttng_ust_context
*context_param
,
1289 struct lttng_ctx
**ctx
, struct lttng_session
*session
)
1292 * We cannot attach a context after trace has been started for a
1293 * session because the metadata does not allow expressing this
1294 * information outside of the original channel scope.
1296 if (session
->been_active
)
1299 switch (context_param
->ctx
) {
1300 case LTTNG_UST_CONTEXT_PTHREAD_ID
:
1301 return lttng_add_pthread_id_to_ctx(ctx
);
1302 case LTTNG_UST_CONTEXT_VTID
:
1303 return lttng_add_vtid_to_ctx(ctx
);
1304 case LTTNG_UST_CONTEXT_VPID
:
1305 return lttng_add_vpid_to_ctx(ctx
);
1306 case LTTNG_UST_CONTEXT_PROCNAME
:
1307 return lttng_add_procname_to_ctx(ctx
);
1313 int lttng_enabler_attach_context(struct lttng_enabler
*enabler
,
1314 struct lttng_ust_context
*context_param
)
1316 #if 0 // disabled for now.
1317 struct lttng_session
*session
= enabler
->chan
->session
;
1320 ret
= lttng_attach_context(context_param
, &enabler
->ctx
,
1324 lttng_session_lazy_sync_enablers(enabler
->chan
->session
);
1330 void lttng_enabler_destroy(struct lttng_enabler
*enabler
)
1332 struct lttng_ust_filter_bytecode_node
*filter_node
, *tmp_filter_node
;
1334 /* Destroy filter bytecode */
1335 cds_list_for_each_entry_safe(filter_node
, tmp_filter_node
,
1336 &enabler
->filter_bytecode_head
, node
) {
1340 /* Destroy contexts */
1341 lttng_destroy_context(enabler
->ctx
);
1343 cds_list_del(&enabler
->node
);
1348 * lttng_session_sync_enablers should be called just before starting a
1352 void lttng_session_sync_enablers(struct lttng_session
*session
)
1354 struct lttng_enabler
*enabler
;
1355 struct lttng_event
*event
;
1357 cds_list_for_each_entry(enabler
, &session
->enablers_head
, node
)
1358 lttng_enabler_ref_events(enabler
);
1360 * For each event, if at least one of its enablers is enabled,
1361 * we enable the event, else we disable it.
1363 cds_list_for_each_entry(event
, &session
->events_head
, node
) {
1364 struct lttng_enabler_ref
*enabler_ref
;
1365 struct lttng_bytecode_runtime
*runtime
;
1366 int enabled
= 0, has_enablers_without_bytecode
= 0;
1369 cds_list_for_each_entry(enabler_ref
,
1370 &event
->enablers_ref_head
, node
) {
1371 if (enabler_ref
->ref
->enabled
) {
1376 event
->enabled
= enabled
;
1378 /* Check if has enablers without bytecode enabled */
1379 cds_list_for_each_entry(enabler_ref
,
1380 &event
->enablers_ref_head
, node
) {
1381 if (enabler_ref
->ref
->enabled
1382 && cds_list_empty(&enabler_ref
->ref
->filter_bytecode_head
)) {
1383 has_enablers_without_bytecode
= 1;
1387 event
->has_enablers_without_bytecode
=
1388 has_enablers_without_bytecode
;
1390 /* Enable filters */
1391 cds_list_for_each_entry(runtime
,
1392 &event
->bytecode_runtime_head
, node
) {
1393 lttng_filter_sync_state(runtime
);
1399 * Apply enablers to session events, adding events to session if need
1400 * be. It is required after each modification applied to an active
1401 * session, and right before session "start".
1402 * "lazy" sync means we only sync if required.
1405 void lttng_session_lazy_sync_enablers(struct lttng_session
*session
)
1407 /* We can skip if session is not active */
1408 if (!session
->active
)
1410 lttng_session_sync_enablers(session
);