- const struct lttng_event_desc *desc = event->desc;
- int ret = 0;
- int i;
-
- for (i = 0; i < desc->nr_fields; i++) {
- const struct lttng_event_field *field = &desc->fields[i];
-
- ret = _lttng_field_statedump(session, field);
- if (ret)
- return ret;
- }
- return ret;
-}
-
-static
-int _lttng_event_metadata_statedump(struct lttng_session *session,
- struct lttng_channel *chan,
- struct lttng_event *event)
-{
- int ret = 0;
- int loglevel = TRACE_DEFAULT;
-
- if (event->metadata_dumped || !CMM_ACCESS_ONCE(session->active))
- return 0;
- if (chan == session->metadata)
- return 0;
- /*
- * Don't print events for which probe load is pending.
- */
- if (!event->desc)
- return 0;
-
- ret = lttng_metadata_printf(session,
- "event {\n"
- " name = \"%s\";\n"
- " id = %u;\n"
- " stream_id = %u;\n",
- event->desc->name,
- event->id,
- event->chan->id);
- if (ret)
- goto end;
-
- if (event->desc->loglevel)
- loglevel = *(*event->desc->loglevel);
-
- ret = lttng_metadata_printf(session,
- " loglevel = %d;\n",
- loglevel);
- if (ret)
- goto end;
-
- if (event->desc->u.ext.model_emf_uri) {
- ret = lttng_metadata_printf(session,
- " model.emf.uri = \"%s\";\n",
- *(event->desc->u.ext.model_emf_uri));
- if (ret)
- goto end;
- }
-
- if (event->ctx) {
- ret = lttng_metadata_printf(session,
- " context := struct {\n");
- if (ret)
- goto end;
- }
- ret = _lttng_context_metadata_statedump(session, event->ctx);
- if (ret)
- goto end;
- if (event->ctx) {
- ret = lttng_metadata_printf(session,
- " };\n");
- if (ret)
- goto end;
- }
-
- ret = lttng_metadata_printf(session,
- " fields := struct {\n"
- );
- if (ret)
- goto end;
-
- ret = _lttng_fields_metadata_statedump(session, event);
- if (ret)
- goto end;
-
- /*
- * LTTng space reservation can only reserve multiples of the
- * byte size.
- */
- ret = lttng_metadata_printf(session,
- " };\n"
- "};\n\n");
- if (ret)
- goto end;
-
- event->metadata_dumped = 1;
-end:
- return ret;
-
-}
-
-static
-int _lttng_channel_metadata_statedump(struct lttng_session *session,
- struct lttng_channel *chan)
-{
- int ret = 0;
-
- if (chan->metadata_dumped || !CMM_ACCESS_ONCE(session->active))
- return 0;
- if (chan == session->metadata)
- return 0;
-
- WARN_ON_ONCE(!chan->header_type);
- ret = lttng_metadata_printf(session,
- "stream {\n"
- " id = %u;\n"
- " event.header := %s;\n"
- " packet.context := struct packet_context;\n",
- chan->id,
- chan->header_type == 1 ? "struct event_header_compact" :
- "struct event_header_large");
- if (ret)
- goto end;
-
- if (chan->ctx) {
- ret = lttng_metadata_printf(session,
- " event.context := struct {\n");
- if (ret)
- goto end;
- }
- ret = _lttng_context_metadata_statedump(session, chan->ctx);
- if (ret)
- goto end;
- if (chan->ctx) {
- ret = lttng_metadata_printf(session,
- " };\n");
- if (ret)
- goto end;
- }
-
- ret = lttng_metadata_printf(session,
- "};\n\n");
-
- chan->metadata_dumped = 1;
-end:
- return ret;
-}
-
-static
-int _lttng_stream_packet_context_declare(struct lttng_session *session)
-{
- return lttng_metadata_printf(session,
- "struct packet_context {\n"
- " uint64_clock_monotonic_t timestamp_begin;\n"
- " uint64_clock_monotonic_t timestamp_end;\n"
- " uint64_t content_size;\n"
- " uint64_t packet_size;\n"
- " unsigned long events_discarded;\n"
- " uint32_t cpu_id;\n"
- "};\n\n"
- );
-}
-
-/*
- * Compact header:
- * id: range: 0 - 30.
- * id 31 is reserved to indicate an extended header.
- *
- * Large header:
- * id: range: 0 - 65534.
- * id 65535 is reserved to indicate an extended header.
- */
-static
-int _lttng_event_header_declare(struct lttng_session *session)
-{
- return lttng_metadata_printf(session,
- "struct event_header_compact {\n"
- " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
- " variant <id> {\n"
- " struct {\n"
- " uint27_clock_monotonic_t timestamp;\n"
- " } compact;\n"
- " struct {\n"
- " uint32_t id;\n"
- " uint64_clock_monotonic_t timestamp;\n"
- " } extended;\n"
- " } v;\n"
- "} align(%u);\n"
- "\n"
- "struct event_header_large {\n"
- " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
- " variant <id> {\n"
- " struct {\n"
- " uint32_clock_monotonic_t timestamp;\n"
- " } compact;\n"
- " struct {\n"
- " uint32_t id;\n"
- " uint64_clock_monotonic_t timestamp;\n"
- " } extended;\n"
- " } v;\n"
- "} align(%u);\n\n",
- lttng_alignof(uint32_t) * CHAR_BIT,
- lttng_alignof(uint16_t) * CHAR_BIT
- );
-}
-
-/*
- * Approximation of NTP time of day to clock monotonic correlation,
- * taken at start of trace.
- * Yes, this is only an approximation. Yes, we can (and will) do better
- * in future versions.
- */
-static
-uint64_t measure_clock_offset(void)
-{
- uint64_t offset, monotonic[2], realtime;
- struct timespec rts = { 0, 0 };
- int ret;
-
- monotonic[0] = trace_clock_read64();
- ret = clock_gettime(CLOCK_REALTIME, &rts);
- if (ret < 0)
- return 0;
- monotonic[1] = trace_clock_read64();
- offset = (monotonic[0] + monotonic[1]) >> 1;
- realtime = (uint64_t) rts.tv_sec * 1000000000ULL;
- realtime += rts.tv_nsec;
- offset = realtime - offset;
- return offset;
-}
-
-/*
- * Output metadata into this session's metadata buffers.
- */
-static
-int _lttng_session_metadata_statedump(struct lttng_session *session)
-{
- unsigned char *uuid_c = session->uuid;
- char uuid_s[LTTNG_UST_UUID_STR_LEN],
- clock_uuid_s[LTTNG_UST_UUID_STR_LEN];
- struct lttng_channel *chan;
- struct lttng_event *event;
- int ret = 0;
- char procname[LTTNG_UST_PROCNAME_LEN] = "";
- char hostname[HOST_NAME_MAX];
-
- if (!CMM_ACCESS_ONCE(session->active))
- return 0;
- if (session->metadata_dumped)
- goto skip_session;
- if (!session->metadata) {
- DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n");
- return -EPERM;
- }
-
- snprintf(uuid_s, sizeof(uuid_s),
- "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
- uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
- uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
- uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
- uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
-
- ret = lttng_metadata_printf(session,
- "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
- "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
- "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
- "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
- "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
- "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
- "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
- "\n"
- "trace {\n"
- " major = %u;\n"
- " minor = %u;\n"
- " uuid = \"%s\";\n"
- " byte_order = %s;\n"
- " packet.header := struct {\n"
- " uint32_t magic;\n"
- " uint8_t uuid[16];\n"
- " uint32_t stream_id;\n"
- " };\n"
- "};\n\n",
- lttng_alignof(uint8_t) * CHAR_BIT,
- lttng_alignof(uint16_t) * CHAR_BIT,
- lttng_alignof(uint32_t) * CHAR_BIT,
- lttng_alignof(uint64_t) * CHAR_BIT,
- sizeof(unsigned long) * CHAR_BIT,
- lttng_alignof(unsigned long) * CHAR_BIT,
- CTF_SPEC_MAJOR,
- CTF_SPEC_MINOR,
- uuid_s,
-#if (BYTE_ORDER == BIG_ENDIAN)
- "be"
-#else
- "le"
-#endif
- );
- if (ret)
- goto end;
-
- /* ignore error, just use empty string if error. */
- hostname[0] = '\0';
- ret = gethostname(hostname, sizeof(hostname));
- if (ret && errno == ENAMETOOLONG)
- hostname[HOST_NAME_MAX - 1] = '\0';
- lttng_ust_getprocname(procname);
- procname[LTTNG_UST_PROCNAME_LEN - 1] = '\0';
- ret = lttng_metadata_printf(session,
- "env {\n"
- " hostname = \"%s\";\n"
- " vpid = %d;\n"
- " procname = \"%s\";\n"
- " domain = \"ust\";\n"
- " tracer_name = \"lttng-ust\";\n"
- " tracer_major = %u;\n"
- " tracer_minor = %u;\n"
- " tracer_patchlevel = %u;\n"
- "};\n\n",
- hostname,
- (int) getpid(),
- procname,
- LTTNG_UST_MAJOR_VERSION,
- LTTNG_UST_MINOR_VERSION,
- LTTNG_UST_PATCHLEVEL_VERSION
- );
- if (ret)
- goto end;
-
- ret = lttng_metadata_printf(session,
- "clock {\n"
- " name = %s;\n",
- "monotonic"
- );
- if (ret)
- goto end;
-
- if (!trace_clock_uuid(clock_uuid_s)) {
- ret = lttng_metadata_printf(session,
- " uuid = \"%s\";\n",
- clock_uuid_s
- );
- if (ret)
- goto end;
- }
-
- ret = lttng_metadata_printf(session,
- " description = \"Monotonic Clock\";\n"
- " freq = %" PRIu64 "; /* Frequency, in Hz */\n"
- " /* clock value offset from Epoch is: offset * (1/freq) */\n"
- " offset = %" PRIu64 ";\n"
- "};\n\n",
- trace_clock_freq(),
- measure_clock_offset()
- );
- if (ret)
- goto end;
-
- ret = lttng_metadata_printf(session,
- "typealias integer {\n"
- " size = 27; align = 1; signed = false;\n"
- " map = clock.monotonic.value;\n"
- "} := uint27_clock_monotonic_t;\n"
- "\n"
- "typealias integer {\n"
- " size = 32; align = %u; signed = false;\n"
- " map = clock.monotonic.value;\n"
- "} := uint32_clock_monotonic_t;\n"
- "\n"
- "typealias integer {\n"
- " size = 64; align = %u; signed = false;\n"
- " map = clock.monotonic.value;\n"
- "} := uint64_clock_monotonic_t;\n\n",
- lttng_alignof(uint32_t) * CHAR_BIT,
- lttng_alignof(uint64_t) * CHAR_BIT
- );
- if (ret)
- goto end;
-
- ret = _lttng_stream_packet_context_declare(session);
- if (ret)
- goto end;
-
- ret = _lttng_event_header_declare(session);
- if (ret)
- goto end;
-
-skip_session:
- cds_list_for_each_entry(chan, &session->chan_head, node) {
- ret = _lttng_channel_metadata_statedump(session, chan);
- if (ret)
- goto end;
- }
-
- cds_list_for_each_entry(event, &session->events_head, node) {
- ret = _lttng_event_metadata_statedump(session, event->chan, event);
- if (ret)
- goto end;
- }
- session->metadata_dumped = 1;
-end:
- return ret;