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
);
100 if (name_len
> LTTNG_UST_SYM_NAME_LEN
- 1) {
101 WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name
, LTTNG_UST_SYM_NAME_LEN
- 1);
102 name_len
= LTTNG_UST_SYM_NAME_LEN
- 1;
104 hash
= jhash(name
, name_len
, 0);
105 head
= &pending_probe_table
[hash
& (PENDING_PROBE_HASH_SIZE
- 1)];
106 e
= zmalloc(sizeof(struct ust_pending_probe
) + name_len
);
109 memcpy(&e
->name
[0], name
, name_len
+ 1);
110 e
->name
[name_len
] = '\0';
111 cds_hlist_add_head(&e
->node
, head
);
113 event
->pending_probe
= e
;
118 * remove a pending probe. called when at event teardown and when an
119 * event is fixed (probe is loaded).
120 * called with session mutex held.
123 void remove_pending_probe(struct ust_pending_probe
*e
)
127 cds_hlist_del(&e
->node
);
132 * Called at library load: connect the probe on the events pending on
134 * called with session mutex held.
136 int pending_probe_fix_events(const struct lttng_event_desc
*desc
)
138 struct cds_hlist_head
*head
;
139 struct cds_hlist_node
*node
, *p
;
140 struct ust_pending_probe
*e
;
141 const char *name
= desc
->name
;
143 struct lttng_ust_event event_param
;
144 size_t name_len
= strlen(name
);
148 * For this event, we need to lookup the loglevel. If active (in
149 * the active loglevels hash table), we must create the event.
151 if (desc
->loglevel
) {
152 const struct tracepoint_loglevel_entry
*ev_ll
;
153 struct loglevel_entry
*loglevel
;
155 ev_ll
= *desc
->loglevel
;
156 loglevel
= get_loglevel(ev_ll
->identifier
);
158 loglevel
= get_loglevel_value(ev_ll
->value
);
160 struct session_loglevel
*sl
;
162 cds_list_for_each_entry(sl
, &loglevel
->session_list
,
164 struct ltt_event
*ev
;
167 memcpy(&event_param
, &sl
->event_param
,
168 sizeof(event_param
));
169 memcpy(event_param
.name
,
171 sizeof(event_param
.name
));
173 ret
= ltt_event_create(sl
->chan
,
177 DBG("Error creating event");
180 cds_list_add(&ev
->loglevel_list
,
188 struct wildcard_entry
*wildcard
;
190 wildcard
= match_wildcard(desc
->name
);
191 if (strcmp(desc
->name
, "lttng_ust:metadata") && wildcard
) {
192 struct session_wildcard
*sw
;
194 cds_list_for_each_entry(sw
, &wildcard
->session_list
,
196 struct ltt_event
*ev
;
199 memcpy(&event_param
, &sw
->event_param
,
200 sizeof(event_param
));
201 memcpy(event_param
.name
,
203 sizeof(event_param
.name
));
205 ret
= ltt_event_create(sw
->chan
,
209 DBG("Error creating event");
212 cds_list_add(&ev
->wildcard_list
,
218 if (name_len
> LTTNG_UST_SYM_NAME_LEN
- 1) {
219 WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name
, LTTNG_UST_SYM_NAME_LEN
- 1);
220 name_len
= LTTNG_UST_SYM_NAME_LEN
- 1;
222 hash
= jhash(name
, name_len
, 0);
223 head
= &pending_probe_table
[hash
& (PENDING_PROBE_HASH_SIZE
- 1)];
224 cds_hlist_for_each_entry_safe(e
, node
, p
, head
, node
) {
225 struct ltt_event
*event
;
226 struct ltt_channel
*chan
;
228 if (strncmp(name
, e
->name
, LTTNG_UST_SYM_NAME_LEN
- 1))
232 assert(!event
->desc
);
234 event
->pending_probe
= NULL
;
235 remove_pending_probe(e
);
236 ret
|= __tracepoint_probe_register(name
,
237 event
->desc
->probe_callback
,
241 event
->id
= chan
->free_event_id
++;
242 ret
|= _ltt_event_metadata_statedump(chan
->session
, chan
,
248 void synchronize_trace(void)
253 struct ltt_session
*ltt_session_create(void)
255 struct ltt_session
*session
;
257 session
= zmalloc(sizeof(struct ltt_session
));
260 CDS_INIT_LIST_HEAD(&session
->chan
);
261 CDS_INIT_LIST_HEAD(&session
->events
);
262 CDS_INIT_LIST_HEAD(&session
->loglevels
);
263 CDS_INIT_LIST_HEAD(&session
->wildcards
);
264 uuid_generate(session
->uuid
);
265 cds_list_add(&session
->list
, &sessions
);
269 void ltt_session_destroy(struct ltt_session
*session
)
271 struct ltt_channel
*chan
, *tmpchan
;
272 struct ltt_event
*event
, *tmpevent
;
273 struct session_loglevel
*loglevel
, *tmploglevel
;
274 struct session_wildcard
*wildcard
, *tmpwildcard
;
277 CMM_ACCESS_ONCE(session
->active
) = 0;
278 cds_list_for_each_entry(event
, &session
->events
, list
) {
279 ret
= _ltt_event_unregister(event
);
282 synchronize_trace(); /* Wait for in-flight events to complete */
283 cds_list_for_each_entry_safe(loglevel
, tmploglevel
, &session
->loglevels
, list
)
284 _ltt_loglevel_destroy(loglevel
);
285 cds_list_for_each_entry_safe(wildcard
, tmpwildcard
, &session
->wildcards
, list
)
286 _ltt_wildcard_destroy(wildcard
);
287 cds_list_for_each_entry_safe(event
, tmpevent
, &session
->events
, list
)
288 _ltt_event_destroy(event
);
289 cds_list_for_each_entry_safe(chan
, tmpchan
, &session
->chan
, list
)
290 _ltt_channel_destroy(chan
);
291 cds_list_del(&session
->list
);
295 int ltt_session_enable(struct ltt_session
*session
)
298 struct ltt_channel
*chan
;
300 if (session
->active
) {
306 * Snapshot the number of events per channel to know the type of header
309 cds_list_for_each_entry(chan
, &session
->chan
, list
) {
310 if (chan
->header_type
)
311 continue; /* don't change it if session stop/restart */
313 * Because we don't use any timer in the application, we
314 * currently cannot guarantee that we have frequent
315 * events that let us detect 27-bit overflows.
316 * Therefore, for now, we force large event headers,
317 * which contain 64-bit timestamps.
319 chan
->header_type
= 2; /* large */
321 if (chan
->free_event_id
< 31)
322 chan
->header_type
= 1; /* compact */
324 chan
->header_type
= 2; /* large */
328 CMM_ACCESS_ONCE(session
->active
) = 1;
329 CMM_ACCESS_ONCE(session
->been_active
) = 1;
330 ret
= _ltt_session_metadata_statedump(session
);
332 CMM_ACCESS_ONCE(session
->active
) = 0;
337 int ltt_session_disable(struct ltt_session
*session
)
341 if (!session
->active
) {
345 CMM_ACCESS_ONCE(session
->active
) = 0;
350 int ltt_channel_enable(struct ltt_channel
*channel
)
354 if (channel
== channel
->session
->metadata
)
356 old
= uatomic_xchg(&channel
->enabled
, 1);
362 int ltt_channel_disable(struct ltt_channel
*channel
)
366 if (channel
== channel
->session
->metadata
)
368 old
= uatomic_xchg(&channel
->enabled
, 0);
374 int ltt_event_enable(struct ltt_event
*event
)
378 if (event
->chan
== event
->chan
->session
->metadata
)
380 old
= uatomic_xchg(&event
->enabled
, 1);
386 int ltt_event_disable(struct ltt_event
*event
)
390 if (event
->chan
== event
->chan
->session
->metadata
)
392 old
= uatomic_xchg(&event
->enabled
, 0);
398 struct ltt_channel
*ltt_channel_create(struct ltt_session
*session
,
399 const char *transport_name
,
401 size_t subbuf_size
, size_t num_subbuf
,
402 unsigned int switch_timer_interval
,
403 unsigned int read_timer_interval
,
404 int **shm_fd
, int **wait_fd
,
405 uint64_t **memory_map_size
,
406 struct ltt_channel
*chan_priv_init
)
408 struct ltt_channel
*chan
= NULL
;
409 struct ltt_transport
*transport
;
411 if (session
->been_active
)
412 goto active
; /* Refuse to add channel to active session */
413 transport
= ltt_transport_find(transport_name
);
415 DBG("LTTng transport %s not found\n",
419 chan_priv_init
->id
= session
->free_chan_id
++;
420 chan_priv_init
->session
= session
;
422 * Note: the channel creation op already writes into the packet
423 * headers. Therefore the "chan" information used as input
424 * should be already accessible.
426 chan
= transport
->ops
.channel_create("[lttng]", buf_addr
,
427 subbuf_size
, num_subbuf
, switch_timer_interval
,
428 read_timer_interval
, shm_fd
, wait_fd
,
429 memory_map_size
, chan_priv_init
);
433 chan
->ops
= &transport
->ops
;
434 cds_list_add(&chan
->list
, &session
->chan
);
444 * Only used internally at session destruction.
447 void _ltt_channel_destroy(struct ltt_channel
*chan
)
449 cds_list_del(&chan
->list
);
450 lttng_destroy_context(chan
->ctx
);
451 chan
->ops
->channel_destroy(chan
);
454 int ltt_loglevel_create(struct ltt_channel
*chan
,
455 struct lttng_ust_event
*event_param
,
456 struct session_loglevel
**_sl
)
458 struct session_loglevel
*sl
;
460 sl
= add_loglevel(event_param
->name
, chan
, event_param
);
461 if (!sl
|| IS_ERR(sl
)) {
469 void _ltt_loglevel_destroy(struct session_loglevel
*sl
)
471 _remove_loglevel(sl
);
474 int ltt_wildcard_create(struct ltt_channel
*chan
,
475 struct lttng_ust_event
*event_param
,
476 struct session_wildcard
**_sw
)
478 struct session_wildcard
*sw
;
480 sw
= add_wildcard(event_param
->name
, chan
, event_param
);
481 if (!sw
|| IS_ERR(sw
)) {
489 void _ltt_wildcard_destroy(struct session_wildcard
*sw
)
491 _remove_wildcard(sw
);
495 * Supports event creation while tracing session is active.
497 int ltt_event_create(struct ltt_channel
*chan
,
498 struct lttng_ust_event
*event_param
,
500 struct ltt_event
**_event
)
502 struct ltt_event
*event
;
505 if (chan
->used_event_id
== -1UL) {
510 * This is O(n^2) (for each event, the loop is called at event
511 * creation). Might require a hash if we have lots of events.
513 cds_list_for_each_entry(event
, &chan
->session
->events
, list
) {
514 if (event
->desc
&& !strncmp(event
->desc
->name
,
516 LTTNG_UST_SYM_NAME_LEN
- 1)) {
521 event
= zmalloc(sizeof(struct ltt_event
));
527 event
->filter
= filter
;
529 * used_event_id counts the maximum number of event IDs that can
530 * register if all probes register.
532 chan
->used_event_id
++;
534 event
->instrumentation
= event_param
->instrumentation
;
535 /* Populate ltt_event structure before tracepoint registration. */
537 switch (event_param
->instrumentation
) {
538 case LTTNG_UST_TRACEPOINT
:
539 event
->desc
= ltt_event_get(event_param
->name
);
541 ret
= __tracepoint_probe_register(event_param
->name
,
542 event
->desc
->probe_callback
,
546 event
->id
= chan
->free_event_id
++;
549 * If the probe is not present, event->desc stays NULL,
550 * waiting for the probe to register, and the event->id
553 ret
= add_pending_probe(event
, event_param
->name
);
555 goto add_pending_error
;
558 case LTTNG_UST_TRACEPOINT_LOGLEVEL
:
565 ret
= _ltt_event_metadata_statedump(chan
->session
, chan
, event
);
567 goto statedump_error
;
569 cds_list_add(&event
->list
, &chan
->session
->events
);
575 WARN_ON_ONCE(__tracepoint_probe_unregister(event_param
->name
,
576 event
->desc
->probe_callback
,
578 ltt_event_put(event
->desc
);
590 * Only used internally at session destruction.
592 int _ltt_event_unregister(struct ltt_event
*event
)
596 switch (event
->instrumentation
) {
597 case LTTNG_UST_TRACEPOINT
:
599 ret
= __tracepoint_probe_unregister(event
->desc
->name
,
600 event
->desc
->probe_callback
,
605 remove_pending_probe(event
->pending_probe
);
616 * Only used internally at session destruction.
619 void _ltt_event_destroy(struct ltt_event
*event
)
621 switch (event
->instrumentation
) {
622 case LTTNG_UST_TRACEPOINT
:
624 ltt_event_put(event
->desc
);
630 cds_list_del(&event
->list
);
631 lttng_destroy_context(event
->ctx
);
636 * We have exclusive access to our metadata buffer (protected by the
637 * ust_lock), so we can do racy operations such as looking for
638 * remaining space left in packet and write, since mutual exclusion
639 * protects us from concurrent writes.
641 int lttng_metadata_printf(struct ltt_session
*session
,
642 const char *fmt
, ...)
644 struct lttng_ust_lib_ring_buffer_ctx ctx
;
645 struct ltt_channel
*chan
= session
->metadata
;
647 int ret
= 0, waitret
;
648 size_t len
, reserve_len
, pos
;
651 WARN_ON_ONCE(!CMM_ACCESS_ONCE(session
->active
));
654 ret
= vasprintf(&str
, fmt
, ap
);
662 for (pos
= 0; pos
< len
; pos
+= reserve_len
) {
663 reserve_len
= min_t(size_t,
664 chan
->ops
->packet_avail_size(chan
->chan
, chan
->handle
),
666 lib_ring_buffer_ctx_init(&ctx
, chan
->chan
, NULL
, reserve_len
,
667 sizeof(char), -1, chan
->handle
);
669 * We don't care about metadata buffer's records lost
670 * count, because we always retry here. Report error if
671 * we need to bail out after timeout or being
674 waitret
= wait_cond_interruptible_timeout(
676 ret
= chan
->ops
->event_reserve(&ctx
, 0);
677 ret
!= -ENOBUFS
|| !ret
;
679 LTTNG_METADATA_TIMEOUT_MSEC
);
680 if (waitret
== -ETIMEDOUT
|| waitret
== -EINTR
|| ret
) {
681 DBG("LTTng: Failure to write metadata to buffers (%s)\n",
682 waitret
== -EINTR
? "interrupted" :
683 (ret
== -ENOBUFS
? "timeout" : "I/O error"));
684 if (waitret
== -EINTR
)
688 chan
->ops
->event_write(&ctx
, &str
[pos
], reserve_len
);
689 chan
->ops
->event_commit(&ctx
);
697 int _ltt_field_statedump(struct ltt_session
*session
,
698 const struct lttng_event_field
*field
)
702 switch (field
->type
.atype
) {
704 ret
= lttng_metadata_printf(session
,
705 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
706 field
->type
.u
.basic
.integer
.size
,
707 field
->type
.u
.basic
.integer
.alignment
,
708 field
->type
.u
.basic
.integer
.signedness
,
709 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
711 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
714 field
->type
.u
.basic
.integer
.base
,
715 #if (BYTE_ORDER == BIG_ENDIAN)
716 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
718 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
723 ret
= lttng_metadata_printf(session
,
724 " floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
725 field
->type
.u
.basic
._float
.exp_dig
,
726 field
->type
.u
.basic
._float
.mant_dig
,
727 field
->type
.u
.basic
._float
.alignment
,
728 #if (BYTE_ORDER == BIG_ENDIAN)
729 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
731 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
736 ret
= lttng_metadata_printf(session
,
738 field
->type
.u
.basic
.enumeration
.name
,
743 const struct lttng_basic_type
*elem_type
;
745 elem_type
= &field
->type
.u
.array
.elem_type
;
746 ret
= lttng_metadata_printf(session
,
747 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
748 elem_type
->u
.basic
.integer
.size
,
749 elem_type
->u
.basic
.integer
.alignment
,
750 elem_type
->u
.basic
.integer
.signedness
,
751 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
753 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
756 elem_type
->u
.basic
.integer
.base
,
757 #if (BYTE_ORDER == BIG_ENDIAN)
758 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
760 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
762 field
->name
, field
->type
.u
.array
.length
);
767 const struct lttng_basic_type
*elem_type
;
768 const struct lttng_basic_type
*length_type
;
770 elem_type
= &field
->type
.u
.sequence
.elem_type
;
771 length_type
= &field
->type
.u
.sequence
.length_type
;
772 ret
= lttng_metadata_printf(session
,
773 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
774 length_type
->u
.basic
.integer
.size
,
775 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
776 length_type
->u
.basic
.integer
.signedness
,
777 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
779 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
782 length_type
->u
.basic
.integer
.base
,
783 #if (BYTE_ORDER == BIG_ENDIAN)
784 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
786 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
792 ret
= lttng_metadata_printf(session
,
793 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
794 elem_type
->u
.basic
.integer
.size
,
795 (unsigned int) elem_type
->u
.basic
.integer
.alignment
,
796 elem_type
->u
.basic
.integer
.signedness
,
797 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
799 : ((elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
802 elem_type
->u
.basic
.integer
.base
,
803 #if (BYTE_ORDER == BIG_ENDIAN)
804 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
806 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
814 /* Default encoding is UTF8 */
815 ret
= lttng_metadata_printf(session
,
817 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
818 " { encoding = ASCII; }" : "",
829 int _ltt_context_metadata_statedump(struct ltt_session
*session
,
830 struct lttng_ctx
*ctx
)
837 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
838 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
840 ret
= _ltt_field_statedump(session
, &field
->event_field
);
848 int _ltt_fields_metadata_statedump(struct ltt_session
*session
,
849 struct ltt_event
*event
)
851 const struct lttng_event_desc
*desc
= event
->desc
;
855 for (i
= 0; i
< desc
->nr_fields
; i
++) {
856 const struct lttng_event_field
*field
= &desc
->fields
[i
];
858 ret
= _ltt_field_statedump(session
, field
);
866 int _ltt_event_metadata_statedump(struct ltt_session
*session
,
867 struct ltt_channel
*chan
,
868 struct ltt_event
*event
)
872 if (event
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
874 if (chan
== session
->metadata
)
877 * Don't print events for which probe load is pending.
882 ret
= lttng_metadata_printf(session
,
886 " stream_id = %u;\n",
893 if (event
->desc
->loglevel
) {
894 const struct tracepoint_loglevel_entry
*ll_entry
;
896 ll_entry
= *event
->desc
->loglevel
;
897 ret
= lttng_metadata_printf(session
,
898 " loglevel.identifier = \"%s\";\n"
899 " loglevel.value = %lld;\n",
900 ll_entry
->identifier
,
901 (long long) ll_entry
->value
);
907 ret
= lttng_metadata_printf(session
,
908 " context := struct {\n");
912 ret
= _ltt_context_metadata_statedump(session
, event
->ctx
);
916 ret
= lttng_metadata_printf(session
,
922 ret
= lttng_metadata_printf(session
,
923 " fields := struct {\n"
928 ret
= _ltt_fields_metadata_statedump(session
, event
);
933 * LTTng space reservation can only reserve multiples of the
936 ret
= lttng_metadata_printf(session
,
942 event
->metadata_dumped
= 1;
949 int _ltt_channel_metadata_statedump(struct ltt_session
*session
,
950 struct ltt_channel
*chan
)
954 if (chan
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
956 if (chan
== session
->metadata
)
959 WARN_ON_ONCE(!chan
->header_type
);
960 ret
= lttng_metadata_printf(session
,
963 " event.header := %s;\n"
964 " packet.context := struct packet_context;\n",
966 chan
->header_type
== 1 ? "struct event_header_compact" :
967 "struct event_header_large");
972 ret
= lttng_metadata_printf(session
,
973 " event.context := struct {\n");
977 ret
= _ltt_context_metadata_statedump(session
, chan
->ctx
);
981 ret
= lttng_metadata_printf(session
,
987 ret
= lttng_metadata_printf(session
,
990 chan
->metadata_dumped
= 1;
996 int _ltt_stream_packet_context_declare(struct ltt_session
*session
)
998 return lttng_metadata_printf(session
,
999 "struct packet_context {\n"
1000 " uint64_t timestamp_begin;\n"
1001 " uint64_t timestamp_end;\n"
1002 " uint32_t events_discarded;\n"
1003 " uint32_t content_size;\n"
1004 " uint32_t packet_size;\n"
1005 " uint32_t cpu_id;\n"
1012 * id: range: 0 - 30.
1013 * id 31 is reserved to indicate an extended header.
1016 * id: range: 0 - 65534.
1017 * id 65535 is reserved to indicate an extended header.
1020 int _ltt_event_header_declare(struct ltt_session
*session
)
1022 return lttng_metadata_printf(session
,
1023 "struct event_header_compact {\n"
1024 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
1027 " uint27_t timestamp;\n"
1031 " uint64_t timestamp;\n"
1036 "struct event_header_large {\n"
1037 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
1040 " uint32_t timestamp;\n"
1044 " uint64_t timestamp;\n"
1048 lttng_alignof(uint32_t) * CHAR_BIT
,
1049 lttng_alignof(uint16_t) * CHAR_BIT
1054 * Output metadata into this session's metadata buffers.
1057 int _ltt_session_metadata_statedump(struct ltt_session
*session
)
1059 unsigned char *uuid_c
= session
->uuid
;
1061 struct ltt_channel
*chan
;
1062 struct ltt_event
*event
;
1065 if (!CMM_ACCESS_ONCE(session
->active
))
1067 if (session
->metadata_dumped
)
1069 if (!session
->metadata
) {
1070 DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n");
1074 snprintf(uuid_s
, sizeof(uuid_s
),
1075 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
1076 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
1077 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
1078 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
1079 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
1081 ret
= lttng_metadata_printf(session
,
1082 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
1083 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
1084 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
1085 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
1086 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
1087 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
1093 " byte_order = %s;\n"
1094 " packet.header := struct {\n"
1095 " uint32_t magic;\n"
1096 " uint8_t uuid[16];\n"
1097 " uint32_t stream_id;\n"
1100 lttng_alignof(uint8_t) * CHAR_BIT
,
1101 lttng_alignof(uint16_t) * CHAR_BIT
,
1102 lttng_alignof(uint32_t) * CHAR_BIT
,
1103 lttng_alignof(uint64_t) * CHAR_BIT
,
1107 #if (BYTE_ORDER == BIG_ENDIAN)
1116 ret
= _ltt_stream_packet_context_declare(session
);
1120 ret
= _ltt_event_header_declare(session
);
1125 cds_list_for_each_entry(chan
, &session
->chan
, list
) {
1126 ret
= _ltt_channel_metadata_statedump(session
, chan
);
1131 cds_list_for_each_entry(event
, &session
->events
, list
) {
1132 ret
= _ltt_event_metadata_statedump(session
, event
->chan
, event
);
1136 session
->metadata_dumped
= 1;
1141 void lttng_ust_events_exit(void)
1143 struct ltt_session
*session
, *tmpsession
;
1145 cds_list_for_each_entry_safe(session
, tmpsession
, &sessions
, list
)
1146 ltt_session_destroy(session
);