-/*
- * We have exclusive access to our metadata buffer (protected by the
- * ust_lock), so we can do racy operations such as looking for
- * remaining space left in packet and write, since mutual exclusion
- * protects us from concurrent writes.
- */
-int lttng_metadata_printf(struct lttng_session *session,
- const char *fmt, ...)
-{
- struct lttng_ust_lib_ring_buffer_ctx ctx;
- struct lttng_channel *chan = session->metadata;
- char *str = NULL;
- int ret = 0, waitret;
- size_t len, reserve_len, pos;
- va_list ap;
-
- WARN_ON_ONCE(!CMM_ACCESS_ONCE(session->active));
-
- va_start(ap, fmt);
- ret = vasprintf(&str, fmt, ap);
- va_end(ap);
- if (ret < 0)
- return -ENOMEM;
-
- len = strlen(str);
- pos = 0;
-
- for (pos = 0; pos < len; pos += reserve_len) {
- reserve_len = min_t(size_t,
- chan->ops->packet_avail_size(chan->chan, chan->handle),
- len - pos);
- lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
- sizeof(char), -1, chan->handle);
- /*
- * We don't care about metadata buffer's records lost
- * count, because we always retry here. Report error if
- * we need to bail out after timeout or being
- * interrupted.
- */
- waitret = wait_cond_interruptible_timeout(
- ({
- ret = chan->ops->event_reserve(&ctx, 0);
- ret != -ENOBUFS || !ret;
- }),
- LTTNG_METADATA_TIMEOUT_MSEC);
- if (waitret == -ETIMEDOUT || waitret == -EINTR || ret) {
- DBG("LTTng: Failure to write metadata to buffers (%s)\n",
- waitret == -EINTR ? "interrupted" :
- (ret == -ENOBUFS ? "timeout" : "I/O error"));
- if (waitret == -EINTR)
- ret = waitret;
- goto end;
- }
- chan->ops->event_write(&ctx, &str[pos], reserve_len);
- chan->ops->event_commit(&ctx);
- }
-end:
- free(str);
- return ret;
-}
-
-static
-int _lttng_field_statedump(struct lttng_session *session,
- const struct lttng_event_field *field)
-{
- int ret = 0;
-
- if (field->nowrite)
- return 0;
-
- switch (field->type.atype) {
- case atype_integer:
- ret = lttng_metadata_printf(session,
- " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
- field->type.u.basic.integer.size,
- field->type.u.basic.integer.alignment,
- field->type.u.basic.integer.signedness,
- (field->type.u.basic.integer.encoding == lttng_encode_none)
- ? "none"
- : (field->type.u.basic.integer.encoding == lttng_encode_UTF8)
- ? "UTF8"
- : "ASCII",
- field->type.u.basic.integer.base,
-#if (BYTE_ORDER == BIG_ENDIAN)
- field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
-#else
- field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
-#endif
- field->name);
- break;
- case atype_float:
- ret = lttng_metadata_printf(session,
- " floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
- field->type.u.basic._float.exp_dig,
- field->type.u.basic._float.mant_dig,
- field->type.u.basic._float.alignment,
-#if (BYTE_ORDER == BIG_ENDIAN)
- field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
-#else
- field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
-#endif
- field->name);
- break;
- case atype_enum:
- ret = lttng_metadata_printf(session,
- " %s %s;\n",
- field->type.u.basic.enumeration.name,
- field->name);
- break;
- case atype_array:
- {
- const struct lttng_basic_type *elem_type;
-
- elem_type = &field->type.u.array.elem_type;
- ret = lttng_metadata_printf(session,
- " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
- elem_type->u.basic.integer.size,
- elem_type->u.basic.integer.alignment,
- elem_type->u.basic.integer.signedness,
- (elem_type->u.basic.integer.encoding == lttng_encode_none)
- ? "none"
- : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
- ? "UTF8"
- : "ASCII",
- elem_type->u.basic.integer.base,
-#if (BYTE_ORDER == BIG_ENDIAN)
- elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
-#else
- elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
-#endif
- field->name, field->type.u.array.length);
- break;
- }
- case atype_sequence:
- {
- const struct lttng_basic_type *elem_type;
- const struct lttng_basic_type *length_type;
-
- elem_type = &field->type.u.sequence.elem_type;
- length_type = &field->type.u.sequence.length_type;
- ret = lttng_metadata_printf(session,
- " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
- length_type->u.basic.integer.size,
- (unsigned int) length_type->u.basic.integer.alignment,
- length_type->u.basic.integer.signedness,
- (length_type->u.basic.integer.encoding == lttng_encode_none)
- ? "none"
- : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8)
- ? "UTF8"
- : "ASCII"),
- length_type->u.basic.integer.base,
-#if (BYTE_ORDER == BIG_ENDIAN)
- length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
-#else
- length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
-#endif
- field->name);
- if (ret)
- return ret;
-
- ret = lttng_metadata_printf(session,
- " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
- elem_type->u.basic.integer.size,
- (unsigned int) elem_type->u.basic.integer.alignment,
- elem_type->u.basic.integer.signedness,
- (elem_type->u.basic.integer.encoding == lttng_encode_none)
- ? "none"
- : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8)
- ? "UTF8"
- : "ASCII"),
- elem_type->u.basic.integer.base,
-#if (BYTE_ORDER == BIG_ENDIAN)
- elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "",
-#else
- elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "",
-#endif
- field->name,
- field->name);
- break;
- }
-
- case atype_string:
- /* Default encoding is UTF8 */
- ret = lttng_metadata_printf(session,
- " string%s _%s;\n",
- field->type.u.basic.string.encoding == lttng_encode_ASCII ?
- " { encoding = ASCII; }" : "",
- field->name);
- break;
- default:
- WARN_ON_ONCE(1);
- return -EINVAL;
- }
- return ret;
-}
-
-static
-int _lttng_context_metadata_statedump(struct lttng_session *session,
- struct lttng_ctx *ctx)
-{
- int ret = 0;
- int i;
-
- if (!ctx)
- return 0;
- for (i = 0; i < ctx->nr_fields; i++) {
- const struct lttng_ctx_field *field = &ctx->fields[i];
-
- ret = _lttng_field_statedump(session, &field->event_field);
- if (ret)
- return ret;
- }
- return ret;
-}
-
-static
-int _lttng_fields_metadata_statedump(struct lttng_session *session,
- struct lttng_event *event)
-{
- 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.
- */