src/bin/lttng-sessiond/ust-registry-event.hpp

   1 /*
   2  * Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #ifndef LTTNG_UST_REGISTRY_EVENT_H
   9 #define LTTNG_UST_REGISTRY_EVENT_H
  10
  11 #include "event-class.hpp"
  12 #include "field.hpp"
  13
  14 #include <common/format.hpp>
  15 #include <common/hashtable/hashtable.hpp>
  16 #include <vendor/optional.hpp>
  17
  18 #include <typeinfo>
  19
  20 namespace lttng {
  21 namespace sessiond {
  22 namespace ust {
  23
  24 /*
  25  * Event registered from a UST tracer sent to the session daemon. This is
  26  * indexed and matched by <event_name/signature>.
  27  */
  28 class registry_event : public lttng::sessiond::trace::event_class {
  29 public:
  30         registry_event(unsigned int id,
  31                         unsigned int stream_class_id,
  32                         int session_objd,
  33                         int channel_objd,
  34                         std::string name,
  35                         std::string signature,
  36                         std::vector<lttng::sessiond::trace::field::cuptr> fields,
  37                         int loglevel_value,
  38                         nonstd::optional<std::string> model_emf_uri);
  39         ~registry_event() override = default;
  40
  41         /* Both objd are set by the tracer. */
  42         const int session_objd;
  43         const int channel_objd;
  44         const std::string signature;
  45
  46         /*
  47          * Flag for this channel if the metadata was dumped once during
  48          * registration.
  49          */
  50         bool _metadata_dumped;
  51
  52         /*
  53          * Node in the ust-registry hash table. The event name is used to
  54          * initialize the node and the event_name/signature for the match function.
  55          */
  56         struct cds_lfht_node _node;
  57         struct rcu_head _head;
  58 };
  59
  60 void registry_event_destroy(registry_event *event);
  61
  62 } /* namespace ust */
  63 } /* namespace sessiond */
  64 } /* namespace lttng */
  65
  66 /*
  67  * Due to a bug in g++ < 7.1, this specialization must be enclosed in the fmt namespace,
  68  * see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480.
  69  */
  70 namespace fmt {
  71 template <>
  72 struct formatter<lttng::sessiond::ust::registry_event> : formatter<std::string> {
  73         template <typename FormatContextType>
  74         typename FormatContextType::iterator format(
  75                         const lttng::sessiond::ust::registry_event& event, FormatContextType& ctx)
  76         {
  77                 return format_to(ctx.out(),
  78                                 "{{ name = `{}`, signature = `{}`, id = {}, session objd = {}, channel objd = {} }}",
  79                                 event.name, event.signature, event.id, event.session_objd,
  80                                 event.channel_objd);
  81         }
  82 };
  83 } /* namespace fmt */
  84
  85 #endif /* LTTNG_UST_REGISTRY_EVENT_H */