4 * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 * Holds LTTng per-session event registry.
8 * Dual LGPL v2.1/GPL v2 license.
14 #include <urcu/list.h>
15 #include <urcu/hlist.h>
17 #include <uuid/uuid.h>
25 #include <urcu/compiler.h>
26 #include <urcu/uatomic.h>
27 #include <urcu/arch.h>
29 #include <lttng/tracepoint.h>
30 #include <lttng/ust-events.h>
32 #include <usterr-signal-safe.h>
36 #include "ltt-tracer.h"
37 #include "ltt-tracer-core.h"
39 #include "../libringbuffer/shm.h"
43 * The sessions mutex is the centralized mutex across UST tracing
44 * control and probe registration. All operations within this file are
45 * called by the communication thread, under ust_lock protection.
47 static pthread_mutex_t sessions_mutex
= PTHREAD_MUTEX_INITIALIZER
;
51 pthread_mutex_lock(&sessions_mutex
);
56 pthread_mutex_unlock(&sessions_mutex
);
59 static CDS_LIST_HEAD(sessions
);
62 * Pending probes hash table, containing the registered ltt events for
63 * which tracepoint probes are still missing. Protected by the sessions
66 #define PENDING_PROBE_HASH_BITS 6
67 #define PENDING_PROBE_HASH_SIZE (1 << PENDING_PROBE_HASH_BITS)
68 static struct cds_hlist_head pending_probe_table
[PENDING_PROBE_HASH_SIZE
];
70 struct ust_pending_probe
{
71 struct ltt_event
*event
;
72 struct cds_hlist_node node
;
76 static void _ltt_event_destroy(struct ltt_event
*event
);
77 static void _ltt_loglevel_destroy(struct session_loglevel
*sl
);
78 static void _ltt_wildcard_destroy(struct session_wildcard
*sw
);
79 static void _ltt_channel_destroy(struct ltt_channel
*chan
);
80 static int _ltt_event_unregister(struct ltt_event
*event
);
82 int _ltt_event_metadata_statedump(struct ltt_session
*session
,
83 struct ltt_channel
*chan
,
84 struct ltt_event
*event
);
86 int _ltt_session_metadata_statedump(struct ltt_session
*session
);
89 * called at event creation if probe is missing.
90 * called with session mutex held.
93 int add_pending_probe(struct ltt_event
*event
, const char *name
)
95 struct cds_hlist_head
*head
;
96 struct ust_pending_probe
*e
;
97 size_t name_len
= strlen(name
) + 1;
98 uint32_t hash
= jhash(name
, name_len
- 1, 0);
100 head
= &pending_probe_table
[hash
& (PENDING_PROBE_HASH_SIZE
- 1)];
101 e
= zmalloc(sizeof(struct ust_pending_probe
) + name_len
);
104 memcpy(&e
->name
[0], name
, name_len
);
105 cds_hlist_add_head(&e
->node
, head
);
107 event
->pending_probe
= e
;
112 * remove a pending probe. called when at event teardown and when an
113 * event is fixed (probe is loaded).
114 * called with session mutex held.
117 void remove_pending_probe(struct ust_pending_probe
*e
)
121 cds_hlist_del(&e
->node
);
126 * Called at library load: connect the probe on the events pending on
128 * called with session mutex held.
130 int pending_probe_fix_events(const struct lttng_event_desc
*desc
)
132 struct cds_hlist_head
*head
;
133 struct cds_hlist_node
*node
, *p
;
134 struct ust_pending_probe
*e
;
135 const char *name
= desc
->name
;
136 size_t name_len
= strlen(name
) + 1;
137 uint32_t hash
= jhash(name
, name_len
- 1, 0);
139 struct lttng_ust_event event_param
;
142 * For this event, we need to lookup the loglevel. If active (in
143 * the active loglevels hash table), we must create the event.
145 if (desc
->loglevel
) {
146 const struct tracepoint_loglevel_entry
*ev_ll
;
147 struct loglevel_entry
*loglevel
;
149 ev_ll
= *desc
->loglevel
;
150 loglevel
= get_loglevel(ev_ll
->identifier
);
152 loglevel
= get_loglevel_value(ev_ll
->value
);
154 struct session_loglevel
*sl
;
156 cds_list_for_each_entry(sl
, &loglevel
->session_list
,
158 struct ltt_event
*ev
;
161 memcpy(&event_param
, &sl
->event_param
,
162 sizeof(event_param
));
163 memcpy(event_param
.name
,
165 sizeof(event_param
.name
));
167 ret
= ltt_event_create(sl
->chan
,
171 DBG("Error creating event");
174 cds_list_add(&ev
->loglevel_list
,
182 struct wildcard_entry
*wildcard
;
184 wildcard
= match_wildcard(desc
->name
);
185 if (strcmp(desc
->name
, "lttng_ust:metadata") && wildcard
) {
186 struct session_wildcard
*sw
;
188 cds_list_for_each_entry(sw
, &wildcard
->session_list
,
190 struct ltt_event
*ev
;
193 memcpy(&event_param
, &sw
->event_param
,
194 sizeof(event_param
));
195 memcpy(event_param
.name
,
197 sizeof(event_param
.name
));
199 ret
= ltt_event_create(sw
->chan
,
203 DBG("Error creating event");
206 cds_list_add(&ev
->wildcard_list
,
212 head
= &pending_probe_table
[hash
& (PENDING_PROBE_HASH_SIZE
- 1)];
213 cds_hlist_for_each_entry_safe(e
, node
, p
, head
, node
) {
214 struct ltt_event
*event
;
215 struct ltt_channel
*chan
;
217 if (strcmp(name
, e
->name
))
221 assert(!event
->desc
);
223 event
->pending_probe
= NULL
;
224 remove_pending_probe(e
);
225 ret
|= __tracepoint_probe_register(name
,
226 event
->desc
->probe_callback
,
230 event
->id
= chan
->free_event_id
++;
231 ret
|= _ltt_event_metadata_statedump(chan
->session
, chan
,
237 void synchronize_trace(void)
242 struct ltt_session
*ltt_session_create(void)
244 struct ltt_session
*session
;
246 session
= zmalloc(sizeof(struct ltt_session
));
249 CDS_INIT_LIST_HEAD(&session
->chan
);
250 CDS_INIT_LIST_HEAD(&session
->events
);
251 CDS_INIT_LIST_HEAD(&session
->loglevels
);
252 CDS_INIT_LIST_HEAD(&session
->wildcards
);
253 uuid_generate(session
->uuid
);
254 cds_list_add(&session
->list
, &sessions
);
258 void ltt_session_destroy(struct ltt_session
*session
)
260 struct ltt_channel
*chan
, *tmpchan
;
261 struct ltt_event
*event
, *tmpevent
;
262 struct session_loglevel
*loglevel
, *tmploglevel
;
263 struct session_wildcard
*wildcard
, *tmpwildcard
;
266 CMM_ACCESS_ONCE(session
->active
) = 0;
267 cds_list_for_each_entry(event
, &session
->events
, list
) {
268 ret
= _ltt_event_unregister(event
);
271 synchronize_trace(); /* Wait for in-flight events to complete */
272 cds_list_for_each_entry_safe(loglevel
, tmploglevel
, &session
->loglevels
, list
)
273 _ltt_loglevel_destroy(loglevel
);
274 cds_list_for_each_entry_safe(wildcard
, tmpwildcard
, &session
->wildcards
, list
)
275 _ltt_wildcard_destroy(wildcard
);
276 cds_list_for_each_entry_safe(event
, tmpevent
, &session
->events
, list
)
277 _ltt_event_destroy(event
);
278 cds_list_for_each_entry_safe(chan
, tmpchan
, &session
->chan
, list
)
279 _ltt_channel_destroy(chan
);
280 cds_list_del(&session
->list
);
284 int ltt_session_enable(struct ltt_session
*session
)
287 struct ltt_channel
*chan
;
289 if (session
->active
) {
295 * Snapshot the number of events per channel to know the type of header
298 cds_list_for_each_entry(chan
, &session
->chan
, list
) {
299 if (chan
->header_type
)
300 continue; /* don't change it if session stop/restart */
301 if (chan
->free_event_id
< 31)
302 chan
->header_type
= 1; /* compact */
304 chan
->header_type
= 2; /* large */
307 CMM_ACCESS_ONCE(session
->active
) = 1;
308 CMM_ACCESS_ONCE(session
->been_active
) = 1;
309 ret
= _ltt_session_metadata_statedump(session
);
311 CMM_ACCESS_ONCE(session
->active
) = 0;
316 int ltt_session_disable(struct ltt_session
*session
)
320 if (!session
->active
) {
324 CMM_ACCESS_ONCE(session
->active
) = 0;
329 int ltt_channel_enable(struct ltt_channel
*channel
)
333 if (channel
== channel
->session
->metadata
)
335 old
= uatomic_xchg(&channel
->enabled
, 1);
341 int ltt_channel_disable(struct ltt_channel
*channel
)
345 if (channel
== channel
->session
->metadata
)
347 old
= uatomic_xchg(&channel
->enabled
, 0);
353 int ltt_event_enable(struct ltt_event
*event
)
357 if (event
->chan
== event
->chan
->session
->metadata
)
359 old
= uatomic_xchg(&event
->enabled
, 1);
365 int ltt_event_disable(struct ltt_event
*event
)
369 if (event
->chan
== event
->chan
->session
->metadata
)
371 old
= uatomic_xchg(&event
->enabled
, 0);
377 struct ltt_channel
*ltt_channel_create(struct ltt_session
*session
,
378 const char *transport_name
,
380 size_t subbuf_size
, size_t num_subbuf
,
381 unsigned int switch_timer_interval
,
382 unsigned int read_timer_interval
,
383 int *shm_fd
, int *wait_fd
,
384 uint64_t *memory_map_size
,
385 struct ltt_channel
*chan_priv_init
)
387 struct ltt_channel
*chan
= NULL
;
388 struct ltt_transport
*transport
;
390 if (session
->been_active
)
391 goto active
; /* Refuse to add channel to active session */
392 transport
= ltt_transport_find(transport_name
);
394 DBG("LTTng transport %s not found\n",
398 chan_priv_init
->id
= session
->free_chan_id
++;
399 chan_priv_init
->session
= session
;
401 * Note: the channel creation op already writes into the packet
402 * headers. Therefore the "chan" information used as input
403 * should be already accessible.
405 chan
= transport
->ops
.channel_create("[lttng]", buf_addr
,
406 subbuf_size
, num_subbuf
, switch_timer_interval
,
407 read_timer_interval
, shm_fd
, wait_fd
,
408 memory_map_size
, chan_priv_init
);
412 chan
->ops
= &transport
->ops
;
413 cds_list_add(&chan
->list
, &session
->chan
);
423 * Only used internally at session destruction.
426 void _ltt_channel_destroy(struct ltt_channel
*chan
)
428 cds_list_del(&chan
->list
);
429 lttng_destroy_context(chan
->ctx
);
430 chan
->ops
->channel_destroy(chan
);
433 int ltt_loglevel_create(struct ltt_channel
*chan
,
434 struct lttng_ust_event
*event_param
,
435 struct session_loglevel
**_sl
)
437 struct session_loglevel
*sl
;
439 sl
= add_loglevel(event_param
->name
, chan
, event_param
);
440 if (!sl
|| IS_ERR(sl
)) {
448 void _ltt_loglevel_destroy(struct session_loglevel
*sl
)
450 _remove_loglevel(sl
);
453 int ltt_wildcard_create(struct ltt_channel
*chan
,
454 struct lttng_ust_event
*event_param
,
455 struct session_wildcard
**_sw
)
457 struct session_wildcard
*sw
;
459 sw
= add_wildcard(event_param
->name
, chan
, event_param
);
460 if (!sw
|| IS_ERR(sw
)) {
468 void _ltt_wildcard_destroy(struct session_wildcard
*sw
)
470 _remove_wildcard(sw
);
474 * Supports event creation while tracing session is active.
476 int ltt_event_create(struct ltt_channel
*chan
,
477 struct lttng_ust_event
*event_param
,
479 struct ltt_event
**_event
)
481 struct ltt_event
*event
;
484 if (chan
->used_event_id
== -1UL) {
489 * This is O(n^2) (for each event, the loop is called at event
490 * creation). Might require a hash if we have lots of events.
492 cds_list_for_each_entry(event
, &chan
->session
->events
, list
) {
493 if (event
->desc
&& !strcmp(event
->desc
->name
, event_param
->name
)) {
498 event
= zmalloc(sizeof(struct ltt_event
));
504 event
->filter
= filter
;
506 * used_event_id counts the maximum number of event IDs that can
507 * register if all probes register.
509 chan
->used_event_id
++;
511 event
->instrumentation
= event_param
->instrumentation
;
512 /* Populate ltt_event structure before tracepoint registration. */
514 switch (event_param
->instrumentation
) {
515 case LTTNG_UST_TRACEPOINT
:
516 event
->desc
= ltt_event_get(event_param
->name
);
518 ret
= __tracepoint_probe_register(event_param
->name
,
519 event
->desc
->probe_callback
,
523 event
->id
= chan
->free_event_id
++;
526 * If the probe is not present, event->desc stays NULL,
527 * waiting for the probe to register, and the event->id
530 ret
= add_pending_probe(event
, event_param
->name
);
532 goto add_pending_error
;
535 case LTTNG_UST_TRACEPOINT_LOGLEVEL
:
542 ret
= _ltt_event_metadata_statedump(chan
->session
, chan
, event
);
544 goto statedump_error
;
546 cds_list_add(&event
->list
, &chan
->session
->events
);
552 WARN_ON_ONCE(__tracepoint_probe_unregister(event_param
->name
,
553 event
->desc
->probe_callback
,
555 ltt_event_put(event
->desc
);
567 * Only used internally at session destruction.
569 int _ltt_event_unregister(struct ltt_event
*event
)
573 switch (event
->instrumentation
) {
574 case LTTNG_UST_TRACEPOINT
:
576 ret
= __tracepoint_probe_unregister(event
->desc
->name
,
577 event
->desc
->probe_callback
,
582 remove_pending_probe(event
->pending_probe
);
593 * Only used internally at session destruction.
596 void _ltt_event_destroy(struct ltt_event
*event
)
598 switch (event
->instrumentation
) {
599 case LTTNG_UST_TRACEPOINT
:
601 ltt_event_put(event
->desc
);
607 cds_list_del(&event
->list
);
608 lttng_destroy_context(event
->ctx
);
613 * We have exclusive access to our metadata buffer (protected by the
614 * ust_lock), so we can do racy operations such as looking for
615 * remaining space left in packet and write, since mutual exclusion
616 * protects us from concurrent writes.
618 int lttng_metadata_printf(struct ltt_session
*session
,
619 const char *fmt
, ...)
621 struct lttng_ust_lib_ring_buffer_ctx ctx
;
622 struct ltt_channel
*chan
= session
->metadata
;
624 int ret
= 0, waitret
;
625 size_t len
, reserve_len
, pos
;
628 WARN_ON_ONCE(!CMM_ACCESS_ONCE(session
->active
));
631 ret
= vasprintf(&str
, fmt
, ap
);
639 for (pos
= 0; pos
< len
; pos
+= reserve_len
) {
640 reserve_len
= min_t(size_t,
641 chan
->ops
->packet_avail_size(chan
->chan
, chan
->handle
),
643 lib_ring_buffer_ctx_init(&ctx
, chan
->chan
, NULL
, reserve_len
,
644 sizeof(char), -1, chan
->handle
);
646 * We don't care about metadata buffer's records lost
647 * count, because we always retry here. Report error if
648 * we need to bail out after timeout or being
651 waitret
= wait_cond_interruptible_timeout(
653 ret
= chan
->ops
->event_reserve(&ctx
, 0);
654 ret
!= -ENOBUFS
|| !ret
;
656 LTTNG_METADATA_TIMEOUT_MSEC
);
657 if (waitret
== -ETIMEDOUT
|| waitret
== -EINTR
|| ret
) {
658 DBG("LTTng: Failure to write metadata to buffers (%s)\n",
659 waitret
== -EINTR
? "interrupted" :
660 (ret
== -ENOBUFS
? "timeout" : "I/O error"));
661 if (waitret
== -EINTR
)
665 chan
->ops
->event_write(&ctx
, &str
[pos
], reserve_len
);
666 chan
->ops
->event_commit(&ctx
);
674 int _ltt_field_statedump(struct ltt_session
*session
,
675 const struct lttng_event_field
*field
)
679 switch (field
->type
.atype
) {
681 ret
= lttng_metadata_printf(session
,
682 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
683 field
->type
.u
.basic
.integer
.size
,
684 field
->type
.u
.basic
.integer
.alignment
,
685 field
->type
.u
.basic
.integer
.signedness
,
686 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
688 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
691 field
->type
.u
.basic
.integer
.base
,
692 #if (BYTE_ORDER == BIG_ENDIAN)
693 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
695 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
700 ret
= lttng_metadata_printf(session
,
701 " floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
702 field
->type
.u
.basic
._float
.exp_dig
,
703 field
->type
.u
.basic
._float
.mant_dig
,
704 field
->type
.u
.basic
._float
.alignment
,
705 #if (BYTE_ORDER == BIG_ENDIAN)
706 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
708 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
713 ret
= lttng_metadata_printf(session
,
715 field
->type
.u
.basic
.enumeration
.name
,
720 const struct lttng_basic_type
*elem_type
;
722 elem_type
= &field
->type
.u
.array
.elem_type
;
723 ret
= lttng_metadata_printf(session
,
724 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
725 elem_type
->u
.basic
.integer
.size
,
726 elem_type
->u
.basic
.integer
.alignment
,
727 elem_type
->u
.basic
.integer
.signedness
,
728 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
730 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
733 elem_type
->u
.basic
.integer
.base
,
734 #if (BYTE_ORDER == BIG_ENDIAN)
735 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
737 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
739 field
->name
, field
->type
.u
.array
.length
);
744 const struct lttng_basic_type
*elem_type
;
745 const struct lttng_basic_type
*length_type
;
747 elem_type
= &field
->type
.u
.sequence
.elem_type
;
748 length_type
= &field
->type
.u
.sequence
.length_type
;
749 ret
= lttng_metadata_printf(session
,
750 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
751 length_type
->u
.basic
.integer
.size
,
752 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
753 length_type
->u
.basic
.integer
.signedness
,
754 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
756 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
759 length_type
->u
.basic
.integer
.base
,
760 #if (BYTE_ORDER == BIG_ENDIAN)
761 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
763 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
769 ret
= lttng_metadata_printf(session
,
770 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
771 elem_type
->u
.basic
.integer
.size
,
772 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
773 elem_type
->u
.basic
.integer
.signedness
,
774 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
776 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
779 elem_type
->u
.basic
.integer
.base
,
780 #if (BYTE_ORDER == BIG_ENDIAN)
781 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
783 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
791 /* Default encoding is UTF8 */
792 ret
= lttng_metadata_printf(session
,
794 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
795 " { encoding = ASCII; }" : "",
806 int _ltt_context_metadata_statedump(struct ltt_session
*session
,
807 struct lttng_ctx
*ctx
)
814 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
815 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
817 ret
= _ltt_field_statedump(session
, &field
->event_field
);
825 int _ltt_fields_metadata_statedump(struct ltt_session
*session
,
826 struct ltt_event
*event
)
828 const struct lttng_event_desc
*desc
= event
->desc
;
832 for (i
= 0; i
< desc
->nr_fields
; i
++) {
833 const struct lttng_event_field
*field
= &desc
->fields
[i
];
835 ret
= _ltt_field_statedump(session
, field
);
843 int _ltt_event_metadata_statedump(struct ltt_session
*session
,
844 struct ltt_channel
*chan
,
845 struct ltt_event
*event
)
849 if (event
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
851 if (chan
== session
->metadata
)
854 * Don't print events for which probe load is pending.
859 ret
= lttng_metadata_printf(session
,
863 " stream_id = %u;\n",
870 if (event
->desc
->loglevel
) {
871 const struct tracepoint_loglevel_entry
*ll_entry
;
873 ll_entry
= *event
->desc
->loglevel
;
874 ret
= lttng_metadata_printf(session
,
875 " loglevel.identifier = \"%s\";\n"
876 " loglevel.value = %lld;\n",
877 ll_entry
->identifier
,
878 (long long) ll_entry
->value
);
884 ret
= lttng_metadata_printf(session
,
885 " context := struct {\n");
889 ret
= _ltt_context_metadata_statedump(session
, event
->ctx
);
893 ret
= lttng_metadata_printf(session
,
899 ret
= lttng_metadata_printf(session
,
900 " fields := struct {\n"
905 ret
= _ltt_fields_metadata_statedump(session
, event
);
910 * LTTng space reservation can only reserve multiples of the
913 ret
= lttng_metadata_printf(session
,
919 event
->metadata_dumped
= 1;
926 int _ltt_channel_metadata_statedump(struct ltt_session
*session
,
927 struct ltt_channel
*chan
)
931 if (chan
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
933 if (chan
== session
->metadata
)
936 WARN_ON_ONCE(!chan
->header_type
);
937 ret
= lttng_metadata_printf(session
,
940 " event.header := %s;\n"
941 " packet.context := struct packet_context;\n",
943 chan
->header_type
== 1 ? "struct event_header_compact" :
944 "struct event_header_large");
949 ret
= lttng_metadata_printf(session
,
950 " event.context := struct {\n");
954 ret
= _ltt_context_metadata_statedump(session
, chan
->ctx
);
958 ret
= lttng_metadata_printf(session
,
964 ret
= lttng_metadata_printf(session
,
967 chan
->metadata_dumped
= 1;
973 int _ltt_stream_packet_context_declare(struct ltt_session
*session
)
975 return lttng_metadata_printf(session
,
976 "struct packet_context {\n"
977 " uint64_t timestamp_begin;\n"
978 " uint64_t timestamp_end;\n"
979 " uint32_t events_discarded;\n"
980 " uint32_t content_size;\n"
981 " uint32_t packet_size;\n"
982 " uint32_t cpu_id;\n"
990 * id 31 is reserved to indicate an extended header.
993 * id: range: 0 - 65534.
994 * id 65535 is reserved to indicate an extended header.
997 int _ltt_event_header_declare(struct ltt_session
*session
)
999 return lttng_metadata_printf(session
,
1000 "struct event_header_compact {\n"
1001 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
1004 " uint27_t timestamp;\n"
1008 " uint64_t timestamp;\n"
1013 "struct event_header_large {\n"
1014 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
1017 " uint32_t timestamp;\n"
1021 " uint64_t timestamp;\n"
1025 lttng_alignof(uint32_t) * CHAR_BIT
,
1026 lttng_alignof(uint16_t) * CHAR_BIT
1031 * Output metadata into this session's metadata buffers.
1034 int _ltt_session_metadata_statedump(struct ltt_session
*session
)
1036 unsigned char *uuid_c
= session
->uuid
;
1038 struct ltt_channel
*chan
;
1039 struct ltt_event
*event
;
1042 if (!CMM_ACCESS_ONCE(session
->active
))
1044 if (session
->metadata_dumped
)
1046 if (!session
->metadata
) {
1047 DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n");
1051 snprintf(uuid_s
, sizeof(uuid_s
),
1052 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
1053 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
1054 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
1055 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
1056 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
1058 ret
= lttng_metadata_printf(session
,
1059 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
1060 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
1061 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
1062 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
1063 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
1064 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
1070 " byte_order = %s;\n"
1071 " packet.header := struct {\n"
1072 " uint32_t magic;\n"
1073 " uint8_t uuid[16];\n"
1074 " uint32_t stream_id;\n"
1077 lttng_alignof(uint8_t) * CHAR_BIT
,
1078 lttng_alignof(uint16_t) * CHAR_BIT
,
1079 lttng_alignof(uint32_t) * CHAR_BIT
,
1080 lttng_alignof(uint64_t) * CHAR_BIT
,
1084 #if (BYTE_ORDER == BIG_ENDIAN)
1093 ret
= _ltt_stream_packet_context_declare(session
);
1097 ret
= _ltt_event_header_declare(session
);
1102 cds_list_for_each_entry(chan
, &session
->chan
, list
) {
1103 ret
= _ltt_channel_metadata_statedump(session
, chan
);
1108 cds_list_for_each_entry(event
, &session
->events
, list
) {
1109 ret
= _ltt_event_metadata_statedump(session
, event
->chan
, event
);
1113 session
->metadata_dumped
= 1;
1118 void lttng_ust_events_exit(void)
1120 struct ltt_session
*session
, *tmpsession
;
1122 cds_list_for_each_entry_safe(session
, tmpsession
, &sessions
, list
)
1123 ltt_session_destroy(session
);