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>
28 #include <urcu/compiler.h>
29 #include <urcu/uatomic.h>
30 #include <urcu/arch.h>
32 #include <lttng/tracepoint.h>
33 #include <lttng/ust-events.h>
35 #include <usterr-signal-safe.h>
39 #include "ltt-tracer.h"
40 #include "ltt-tracer-core.h"
42 #include "../libringbuffer/shm.h"
46 * The sessions mutex is the centralized mutex across UST tracing
47 * control and probe registration. All operations within this file are
48 * called by the communication thread, under ust_lock protection.
50 static pthread_mutex_t sessions_mutex
= PTHREAD_MUTEX_INITIALIZER
;
54 pthread_mutex_lock(&sessions_mutex
);
59 pthread_mutex_unlock(&sessions_mutex
);
62 static CDS_LIST_HEAD(sessions
);
65 * Pending probes hash table, containing the registered ltt events for
66 * which tracepoint probes are still missing. Protected by the sessions
69 #define PENDING_PROBE_HASH_BITS 6
70 #define PENDING_PROBE_HASH_SIZE (1 << PENDING_PROBE_HASH_BITS)
71 static struct cds_hlist_head pending_probe_table
[PENDING_PROBE_HASH_SIZE
];
73 struct ust_pending_probe
{
74 struct ltt_event
*event
;
75 struct cds_hlist_node node
;
79 static void _ltt_event_destroy(struct ltt_event
*event
);
80 static void _ltt_wildcard_destroy(struct session_wildcard
*sw
);
81 static void _ltt_channel_destroy(struct ltt_channel
*chan
);
82 static int _ltt_event_unregister(struct ltt_event
*event
);
84 int _ltt_event_metadata_statedump(struct ltt_session
*session
,
85 struct ltt_channel
*chan
,
86 struct ltt_event
*event
);
88 int _ltt_session_metadata_statedump(struct ltt_session
*session
);
91 * called at event creation if probe is missing.
92 * called with session mutex held.
95 int add_pending_probe(struct ltt_event
*event
, const char *name
)
97 struct cds_hlist_head
*head
;
98 struct ust_pending_probe
*e
;
99 size_t name_len
= strlen(name
);
102 if (name_len
> LTTNG_UST_SYM_NAME_LEN
- 1) {
103 WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name
, LTTNG_UST_SYM_NAME_LEN
- 1);
104 name_len
= LTTNG_UST_SYM_NAME_LEN
- 1;
106 hash
= jhash(name
, name_len
, 0);
107 head
= &pending_probe_table
[hash
& (PENDING_PROBE_HASH_SIZE
- 1)];
108 e
= zmalloc(sizeof(struct ust_pending_probe
) + name_len
);
111 memcpy(&e
->name
[0], name
, name_len
+ 1);
112 e
->name
[name_len
] = '\0';
113 cds_hlist_add_head(&e
->node
, head
);
115 event
->pending_probe
= e
;
120 * remove a pending probe. called when at event teardown and when an
121 * event is fixed (probe is loaded).
122 * called with session mutex held.
125 void remove_pending_probe(struct ust_pending_probe
*e
)
129 cds_hlist_del(&e
->node
);
134 * Called at library load: connect the probe on the events pending on
136 * called with session mutex held.
138 int pending_probe_fix_events(const struct lttng_event_desc
*desc
)
140 struct cds_hlist_head
*head
;
141 struct cds_hlist_node
*node
, *p
;
142 struct ust_pending_probe
*e
;
143 const char *name
= desc
->name
;
145 struct lttng_ust_event event_param
;
146 size_t name_len
= strlen(name
);
151 struct wildcard_entry
*wildcard
;
153 /* TODO: check if loglevel match */
154 wildcard
= match_wildcard(desc
->name
);
155 if (strcmp(desc
->name
, "lttng_ust:metadata") && wildcard
) {
156 struct session_wildcard
*sw
;
158 cds_list_for_each_entry(sw
, &wildcard
->session_list
,
160 struct ltt_event
*ev
;
163 memcpy(&event_param
, &sw
->event_param
,
164 sizeof(event_param
));
165 memcpy(event_param
.name
,
167 sizeof(event_param
.name
));
169 ret
= ltt_event_create(sw
->chan
,
173 DBG("Error creating event");
176 cds_list_add(&ev
->wildcard_list
,
182 if (name_len
> LTTNG_UST_SYM_NAME_LEN
- 1) {
183 WARN("Truncating tracepoint name %s which exceeds size limits of %u chars", name
, LTTNG_UST_SYM_NAME_LEN
- 1);
184 name_len
= LTTNG_UST_SYM_NAME_LEN
- 1;
186 hash
= jhash(name
, name_len
, 0);
187 head
= &pending_probe_table
[hash
& (PENDING_PROBE_HASH_SIZE
- 1)];
188 cds_hlist_for_each_entry_safe(e
, node
, p
, head
, node
) {
189 struct ltt_event
*event
;
190 struct ltt_channel
*chan
;
192 /* TODO: check if loglevel match */
193 if (strncmp(name
, e
->name
, LTTNG_UST_SYM_NAME_LEN
- 1))
197 assert(!event
->desc
);
199 event
->pending_probe
= NULL
;
200 remove_pending_probe(e
);
201 ret
|= __tracepoint_probe_register(name
,
202 event
->desc
->probe_callback
,
206 event
->id
= chan
->free_event_id
++;
207 ret
|= _ltt_event_metadata_statedump(chan
->session
, chan
,
213 void synchronize_trace(void)
218 struct ltt_session
*ltt_session_create(void)
220 struct ltt_session
*session
;
222 session
= zmalloc(sizeof(struct ltt_session
));
225 CDS_INIT_LIST_HEAD(&session
->chan
);
226 CDS_INIT_LIST_HEAD(&session
->events
);
227 CDS_INIT_LIST_HEAD(&session
->wildcards
);
228 uuid_generate(session
->uuid
);
229 cds_list_add(&session
->list
, &sessions
);
233 void ltt_session_destroy(struct ltt_session
*session
)
235 struct ltt_channel
*chan
, *tmpchan
;
236 struct ltt_event
*event
, *tmpevent
;
237 struct session_wildcard
*wildcard
, *tmpwildcard
;
240 CMM_ACCESS_ONCE(session
->active
) = 0;
241 cds_list_for_each_entry(event
, &session
->events
, list
) {
242 ret
= _ltt_event_unregister(event
);
245 synchronize_trace(); /* Wait for in-flight events to complete */
246 cds_list_for_each_entry_safe(wildcard
, tmpwildcard
, &session
->wildcards
, list
)
247 _ltt_wildcard_destroy(wildcard
);
248 cds_list_for_each_entry_safe(event
, tmpevent
, &session
->events
, list
)
249 _ltt_event_destroy(event
);
250 cds_list_for_each_entry_safe(chan
, tmpchan
, &session
->chan
, list
)
251 _ltt_channel_destroy(chan
);
252 cds_list_del(&session
->list
);
256 int ltt_session_enable(struct ltt_session
*session
)
259 struct ltt_channel
*chan
;
261 if (session
->active
) {
267 * Snapshot the number of events per channel to know the type of header
270 cds_list_for_each_entry(chan
, &session
->chan
, list
) {
271 if (chan
->header_type
)
272 continue; /* don't change it if session stop/restart */
273 if (chan
->free_event_id
< 31)
274 chan
->header_type
= 1; /* compact */
276 chan
->header_type
= 2; /* large */
279 CMM_ACCESS_ONCE(session
->active
) = 1;
280 CMM_ACCESS_ONCE(session
->been_active
) = 1;
281 ret
= _ltt_session_metadata_statedump(session
);
283 CMM_ACCESS_ONCE(session
->active
) = 0;
288 int ltt_session_disable(struct ltt_session
*session
)
292 if (!session
->active
) {
296 CMM_ACCESS_ONCE(session
->active
) = 0;
301 int ltt_channel_enable(struct ltt_channel
*channel
)
305 if (channel
== channel
->session
->metadata
)
307 old
= uatomic_xchg(&channel
->enabled
, 1);
313 int ltt_channel_disable(struct ltt_channel
*channel
)
317 if (channel
== channel
->session
->metadata
)
319 old
= uatomic_xchg(&channel
->enabled
, 0);
325 int ltt_event_enable(struct ltt_event
*event
)
329 if (event
->chan
== event
->chan
->session
->metadata
)
331 old
= uatomic_xchg(&event
->enabled
, 1);
337 int ltt_event_disable(struct ltt_event
*event
)
341 if (event
->chan
== event
->chan
->session
->metadata
)
343 old
= uatomic_xchg(&event
->enabled
, 0);
349 struct ltt_channel
*ltt_channel_create(struct ltt_session
*session
,
350 const char *transport_name
,
352 size_t subbuf_size
, size_t num_subbuf
,
353 unsigned int switch_timer_interval
,
354 unsigned int read_timer_interval
,
355 int **shm_fd
, int **wait_fd
,
356 uint64_t **memory_map_size
,
357 struct ltt_channel
*chan_priv_init
)
359 struct ltt_channel
*chan
= NULL
;
360 struct ltt_transport
*transport
;
362 if (session
->been_active
)
363 goto active
; /* Refuse to add channel to active session */
364 transport
= ltt_transport_find(transport_name
);
366 DBG("LTTng transport %s not found\n",
370 chan_priv_init
->id
= session
->free_chan_id
++;
371 chan_priv_init
->session
= session
;
373 * Note: the channel creation op already writes into the packet
374 * headers. Therefore the "chan" information used as input
375 * should be already accessible.
377 chan
= transport
->ops
.channel_create("[lttng]", buf_addr
,
378 subbuf_size
, num_subbuf
, switch_timer_interval
,
379 read_timer_interval
, shm_fd
, wait_fd
,
380 memory_map_size
, chan_priv_init
);
384 chan
->ops
= &transport
->ops
;
385 cds_list_add(&chan
->list
, &session
->chan
);
395 * Only used internally at session destruction.
398 void _ltt_channel_destroy(struct ltt_channel
*chan
)
400 cds_list_del(&chan
->list
);
401 lttng_destroy_context(chan
->ctx
);
402 chan
->ops
->channel_destroy(chan
);
405 int ltt_wildcard_create(struct ltt_channel
*chan
,
406 struct lttng_ust_event
*event_param
,
407 struct session_wildcard
**_sw
)
409 struct session_wildcard
*sw
;
411 sw
= add_wildcard(event_param
->name
, chan
, event_param
);
412 if (!sw
|| IS_ERR(sw
)) {
420 void _ltt_wildcard_destroy(struct session_wildcard
*sw
)
422 _remove_wildcard(sw
);
426 * Supports event creation while tracing session is active.
428 int ltt_event_create(struct ltt_channel
*chan
,
429 struct lttng_ust_event
*event_param
,
431 struct ltt_event
**_event
)
433 struct ltt_event
*event
;
436 if (chan
->used_event_id
== -1UL) {
441 * This is O(n^2) (for each event, the loop is called at event
442 * creation). Might require a hash if we have lots of events.
444 cds_list_for_each_entry(event
, &chan
->session
->events
, list
) {
445 if (event
->desc
&& !strncmp(event
->desc
->name
,
447 LTTNG_UST_SYM_NAME_LEN
- 1)) {
452 event
= zmalloc(sizeof(struct ltt_event
));
458 event
->filter
= filter
;
460 * used_event_id counts the maximum number of event IDs that can
461 * register if all probes register.
463 chan
->used_event_id
++;
465 event
->instrumentation
= event_param
->instrumentation
;
466 /* Populate ltt_event structure before tracepoint registration. */
468 switch (event_param
->instrumentation
) {
469 case LTTNG_UST_TRACEPOINT
:
470 event
->desc
= ltt_event_get(event_param
->name
);
471 /* TODO: check if loglevel match */
473 ret
= __tracepoint_probe_register(event_param
->name
,
474 event
->desc
->probe_callback
,
478 event
->id
= chan
->free_event_id
++;
481 * If the probe is not present, event->desc stays NULL,
482 * waiting for the probe to register, and the event->id
485 ret
= add_pending_probe(event
, event_param
->name
);
487 goto add_pending_error
;
494 ret
= _ltt_event_metadata_statedump(chan
->session
, chan
, event
);
496 goto statedump_error
;
498 cds_list_add(&event
->list
, &chan
->session
->events
);
504 WARN_ON_ONCE(__tracepoint_probe_unregister(event_param
->name
,
505 event
->desc
->probe_callback
,
507 ltt_event_put(event
->desc
);
519 * Only used internally at session destruction.
521 int _ltt_event_unregister(struct ltt_event
*event
)
525 switch (event
->instrumentation
) {
526 case LTTNG_UST_TRACEPOINT
:
528 ret
= __tracepoint_probe_unregister(event
->desc
->name
,
529 event
->desc
->probe_callback
,
534 remove_pending_probe(event
->pending_probe
);
545 * Only used internally at session destruction.
548 void _ltt_event_destroy(struct ltt_event
*event
)
550 switch (event
->instrumentation
) {
551 case LTTNG_UST_TRACEPOINT
:
553 ltt_event_put(event
->desc
);
559 cds_list_del(&event
->list
);
560 lttng_destroy_context(event
->ctx
);
565 * We have exclusive access to our metadata buffer (protected by the
566 * ust_lock), so we can do racy operations such as looking for
567 * remaining space left in packet and write, since mutual exclusion
568 * protects us from concurrent writes.
570 int lttng_metadata_printf(struct ltt_session
*session
,
571 const char *fmt
, ...)
573 struct lttng_ust_lib_ring_buffer_ctx ctx
;
574 struct ltt_channel
*chan
= session
->metadata
;
576 int ret
= 0, waitret
;
577 size_t len
, reserve_len
, pos
;
580 WARN_ON_ONCE(!CMM_ACCESS_ONCE(session
->active
));
583 ret
= vasprintf(&str
, fmt
, ap
);
591 for (pos
= 0; pos
< len
; pos
+= reserve_len
) {
592 reserve_len
= min_t(size_t,
593 chan
->ops
->packet_avail_size(chan
->chan
, chan
->handle
),
595 lib_ring_buffer_ctx_init(&ctx
, chan
->chan
, NULL
, reserve_len
,
596 sizeof(char), -1, chan
->handle
);
598 * We don't care about metadata buffer's records lost
599 * count, because we always retry here. Report error if
600 * we need to bail out after timeout or being
603 waitret
= wait_cond_interruptible_timeout(
605 ret
= chan
->ops
->event_reserve(&ctx
, 0);
606 ret
!= -ENOBUFS
|| !ret
;
608 LTTNG_METADATA_TIMEOUT_MSEC
);
609 if (waitret
== -ETIMEDOUT
|| waitret
== -EINTR
|| ret
) {
610 DBG("LTTng: Failure to write metadata to buffers (%s)\n",
611 waitret
== -EINTR
? "interrupted" :
612 (ret
== -ENOBUFS
? "timeout" : "I/O error"));
613 if (waitret
== -EINTR
)
617 chan
->ops
->event_write(&ctx
, &str
[pos
], reserve_len
);
618 chan
->ops
->event_commit(&ctx
);
626 int _ltt_field_statedump(struct ltt_session
*session
,
627 const struct lttng_event_field
*field
)
631 switch (field
->type
.atype
) {
633 ret
= lttng_metadata_printf(session
,
634 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
635 field
->type
.u
.basic
.integer
.size
,
636 field
->type
.u
.basic
.integer
.alignment
,
637 field
->type
.u
.basic
.integer
.signedness
,
638 (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_none
)
640 : (field
->type
.u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
643 field
->type
.u
.basic
.integer
.base
,
644 #if (BYTE_ORDER == BIG_ENDIAN)
645 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
647 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
652 ret
= lttng_metadata_printf(session
,
653 " floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
654 field
->type
.u
.basic
._float
.exp_dig
,
655 field
->type
.u
.basic
._float
.mant_dig
,
656 field
->type
.u
.basic
._float
.alignment
,
657 #if (BYTE_ORDER == BIG_ENDIAN)
658 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
660 field
->type
.u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
665 ret
= lttng_metadata_printf(session
,
667 field
->type
.u
.basic
.enumeration
.name
,
672 const struct lttng_basic_type
*elem_type
;
674 elem_type
= &field
->type
.u
.array
.elem_type
;
675 ret
= lttng_metadata_printf(session
,
676 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
677 elem_type
->u
.basic
.integer
.size
,
678 elem_type
->u
.basic
.integer
.alignment
,
679 elem_type
->u
.basic
.integer
.signedness
,
680 (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
682 : (elem_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
685 elem_type
->u
.basic
.integer
.base
,
686 #if (BYTE_ORDER == BIG_ENDIAN)
687 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
689 elem_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
691 field
->name
, field
->type
.u
.array
.length
);
696 const struct lttng_basic_type
*elem_type
;
697 const struct lttng_basic_type
*length_type
;
699 elem_type
= &field
->type
.u
.sequence
.elem_type
;
700 length_type
= &field
->type
.u
.sequence
.length_type
;
701 ret
= lttng_metadata_printf(session
,
702 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
703 length_type
->u
.basic
.integer
.size
,
704 (unsigned int) length_type
->u
.basic
.integer
.alignment
,
705 length_type
->u
.basic
.integer
.signedness
,
706 (length_type
->u
.basic
.integer
.encoding
== lttng_encode_none
)
708 : ((length_type
->u
.basic
.integer
.encoding
== lttng_encode_UTF8
)
711 length_type
->u
.basic
.integer
.base
,
712 #if (BYTE_ORDER == BIG_ENDIAN)
713 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = le;" : "",
715 length_type
->u
.basic
.integer
.reverse_byte_order
? " byte_order = be;" : "",
721 ret
= lttng_metadata_printf(session
,
722 " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
723 elem_type
->u
.basic
.integer
.size
,
724 (unsigned int) 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;" : "",
743 /* Default encoding is UTF8 */
744 ret
= lttng_metadata_printf(session
,
746 field
->type
.u
.basic
.string
.encoding
== lttng_encode_ASCII
?
747 " { encoding = ASCII; }" : "",
758 int _ltt_context_metadata_statedump(struct ltt_session
*session
,
759 struct lttng_ctx
*ctx
)
766 for (i
= 0; i
< ctx
->nr_fields
; i
++) {
767 const struct lttng_ctx_field
*field
= &ctx
->fields
[i
];
769 ret
= _ltt_field_statedump(session
, &field
->event_field
);
777 int _ltt_fields_metadata_statedump(struct ltt_session
*session
,
778 struct ltt_event
*event
)
780 const struct lttng_event_desc
*desc
= event
->desc
;
784 for (i
= 0; i
< desc
->nr_fields
; i
++) {
785 const struct lttng_event_field
*field
= &desc
->fields
[i
];
787 ret
= _ltt_field_statedump(session
, field
);
795 int _ltt_event_metadata_statedump(struct ltt_session
*session
,
796 struct ltt_channel
*chan
,
797 struct ltt_event
*event
)
801 if (event
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
803 if (chan
== session
->metadata
)
806 * Don't print events for which probe load is pending.
811 ret
= lttng_metadata_printf(session
,
815 " stream_id = %u;\n",
822 if (event
->desc
->loglevel
) {
825 ll_entry
= *event
->desc
->loglevel
;
826 ret
= lttng_metadata_printf(session
,
834 ret
= lttng_metadata_printf(session
,
835 " context := struct {\n");
839 ret
= _ltt_context_metadata_statedump(session
, event
->ctx
);
843 ret
= lttng_metadata_printf(session
,
849 ret
= lttng_metadata_printf(session
,
850 " fields := struct {\n"
855 ret
= _ltt_fields_metadata_statedump(session
, event
);
860 * LTTng space reservation can only reserve multiples of the
863 ret
= lttng_metadata_printf(session
,
869 event
->metadata_dumped
= 1;
876 int _ltt_channel_metadata_statedump(struct ltt_session
*session
,
877 struct ltt_channel
*chan
)
881 if (chan
->metadata_dumped
|| !CMM_ACCESS_ONCE(session
->active
))
883 if (chan
== session
->metadata
)
886 WARN_ON_ONCE(!chan
->header_type
);
887 ret
= lttng_metadata_printf(session
,
890 " event.header := %s;\n"
891 " packet.context := struct packet_context;\n",
893 chan
->header_type
== 1 ? "struct event_header_compact" :
894 "struct event_header_large");
899 ret
= lttng_metadata_printf(session
,
900 " event.context := struct {\n");
904 ret
= _ltt_context_metadata_statedump(session
, chan
->ctx
);
908 ret
= lttng_metadata_printf(session
,
914 ret
= lttng_metadata_printf(session
,
917 chan
->metadata_dumped
= 1;
923 int _ltt_stream_packet_context_declare(struct ltt_session
*session
)
925 return lttng_metadata_printf(session
,
926 "struct packet_context {\n"
927 " uint64_clock_monotonic_t timestamp_begin;\n"
928 " uint64_clock_monotonic_t timestamp_end;\n"
929 " uint32_t events_discarded;\n"
930 " uint32_t content_size;\n"
931 " uint32_t packet_size;\n"
932 " uint32_t cpu_id;\n"
940 * id 31 is reserved to indicate an extended header.
943 * id: range: 0 - 65534.
944 * id 65535 is reserved to indicate an extended header.
947 int _ltt_event_header_declare(struct ltt_session
*session
)
949 return lttng_metadata_printf(session
,
950 "struct event_header_compact {\n"
951 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
954 " uint27_clock_monotonic_t timestamp;\n"
958 " uint64_clock_monotonic_t timestamp;\n"
963 "struct event_header_large {\n"
964 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
967 " uint32_clock_monotonic_t timestamp;\n"
971 " uint64_clock_monotonic_t timestamp;\n"
975 lttng_alignof(uint32_t) * CHAR_BIT
,
976 lttng_alignof(uint16_t) * CHAR_BIT
981 * Approximation of NTP time of day to clock monotonic correlation,
982 * taken at start of trace.
983 * Yes, this is only an approximation. Yes, we can (and will) do better
984 * in future versions.
987 uint64_t measure_clock_offset(void)
989 uint64_t offset
, monotonic
[2], realtime
;
990 struct timespec rts
= { 0, 0 };
993 monotonic
[0] = trace_clock_read64();
994 ret
= clock_gettime(CLOCK_REALTIME
, &rts
);
997 monotonic
[1] = trace_clock_read64();
998 offset
= (monotonic
[0] + monotonic
[1]) >> 1;
999 realtime
= rts
.tv_sec
* 1000000000ULL;
1000 realtime
+= rts
.tv_nsec
;
1001 offset
= realtime
- offset
;
1006 * Output metadata into this session's metadata buffers.
1009 int _ltt_session_metadata_statedump(struct ltt_session
*session
)
1011 unsigned char *uuid_c
= session
->uuid
;
1012 char uuid_s
[37], clock_uuid_s
[CLOCK_UUID_LEN
];
1013 struct ltt_channel
*chan
;
1014 struct ltt_event
*event
;
1017 if (!CMM_ACCESS_ONCE(session
->active
))
1019 if (session
->metadata_dumped
)
1021 if (!session
->metadata
) {
1022 DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n");
1026 snprintf(uuid_s
, sizeof(uuid_s
),
1027 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
1028 uuid_c
[0], uuid_c
[1], uuid_c
[2], uuid_c
[3],
1029 uuid_c
[4], uuid_c
[5], uuid_c
[6], uuid_c
[7],
1030 uuid_c
[8], uuid_c
[9], uuid_c
[10], uuid_c
[11],
1031 uuid_c
[12], uuid_c
[13], uuid_c
[14], uuid_c
[15]);
1033 ret
= lttng_metadata_printf(session
,
1034 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
1035 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
1036 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
1037 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
1038 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
1039 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
1045 " byte_order = %s;\n"
1046 " packet.header := struct {\n"
1047 " uint32_t magic;\n"
1048 " uint8_t uuid[16];\n"
1049 " uint32_t stream_id;\n"
1052 lttng_alignof(uint8_t) * CHAR_BIT
,
1053 lttng_alignof(uint16_t) * CHAR_BIT
,
1054 lttng_alignof(uint32_t) * CHAR_BIT
,
1055 lttng_alignof(uint64_t) * CHAR_BIT
,
1059 #if (BYTE_ORDER == BIG_ENDIAN)
1068 ret
= lttng_metadata_printf(session
,
1076 if (!trace_clock_uuid(clock_uuid_s
)) {
1077 ret
= lttng_metadata_printf(session
,
1078 " uuid = \"%s\";\n",
1085 ret
= lttng_metadata_printf(session
,
1086 " description = \"Monotonic Clock\";\n"
1087 " freq = %" PRIu64
"; /* Frequency, in Hz */\n"
1088 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
1089 " offset = %" PRIu64
";\n"
1092 measure_clock_offset()
1097 ret
= lttng_metadata_printf(session
,
1098 "typealias integer {\n"
1099 " size = 27; align = 1; signed = false;\n"
1100 " map = clock.monotonic.value;\n"
1101 "} := uint27_clock_monotonic_t;\n"
1103 "typealias integer {\n"
1104 " size = 32; align = %u; signed = false;\n"
1105 " map = clock.monotonic.value;\n"
1106 "} := uint32_clock_monotonic_t;\n"
1108 "typealias integer {\n"
1109 " size = 64; align = %u; signed = false;\n"
1110 " map = clock.monotonic.value;\n"
1111 "} := uint64_clock_monotonic_t;\n\n",
1112 lttng_alignof(uint32_t) * CHAR_BIT
,
1113 lttng_alignof(uint64_t) * CHAR_BIT
1118 ret
= _ltt_stream_packet_context_declare(session
);
1122 ret
= _ltt_event_header_declare(session
);
1127 cds_list_for_each_entry(chan
, &session
->chan
, list
) {
1128 ret
= _ltt_channel_metadata_statedump(session
, chan
);
1133 cds_list_for_each_entry(event
, &session
->events
, list
) {
1134 ret
= _ltt_event_metadata_statedump(session
, event
->chan
, event
);
1138 session
->metadata_dumped
= 1;
1143 void lttng_ust_events_exit(void)
1145 struct ltt_session
*session
, *tmpsession
;
1147 cds_list_for_each_entry_safe(session
, tmpsession
, &sessions
, list
)
1148 ltt_session_destroy(session
);