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
  17 #include <vendor/optional.hpp>
  18
  19 #include <typeinfo>
  20
  21 namespace lttng {
  22 namespace sessiond {
  23 namespace ust {
  24
  25 /*
  26  * Event registered from a UST tracer sent to the session daemon. This is
  27  * indexed and matched by <event_name/signature>.
  28  */
  29 class registry_event : public lttng::sessiond::trace::event_class {
  30 public:
  31         registry_event(unsigned int id,
  32                        unsigned int stream_class_id,
  33                        int session_objd,
  34                        int channel_objd,
  35                        std::string name,
  36                        std::string signature,
  37                        std::vector<lttng::sessiond::trace::field::cuptr> fields,
  38                        int loglevel_value,
  39                        nonstd::optional<std::string> model_emf_uri);
  40         ~registry_event() override = default;
  41         registry_event(const registry_event&) = delete;
  42         registry_event(registry_event&&) = delete;
  43         registry_event& operator=(registry_event&&) = delete;
  44         registry_event& operator=(const registry_event&) = delete;
  45
  46         /* Both objd are set by the tracer. */
  47         const int session_objd;
  48         const int channel_objd;
  49         const std::string signature;
  50
  51         /*
  52          * Flag for this channel if the metadata was dumped once during
  53          * registration.
  54          */
  55         bool _metadata_dumped;
  56
  57         /*
  58          * Node in the ust-registry hash table. The event name is used to
  59          * initialize the node and the event_name/signature for the match function.
  60          */
  61         struct cds_lfht_node _node;
  62         struct rcu_head _head;
  63 };
  64
  65 void registry_event_destroy(registry_event *event);
  66
  67 } /* namespace ust */
  68 } /* namespace sessiond */
  69 } /* namespace lttng */
  70
  71 /*
  72  * Due to a bug in g++ < 7.1, this specialization must be enclosed in the fmt namespace,
  73  * see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480.
  74  */
  75 namespace fmt {
  76 template <>
  77 struct formatter<lttng::sessiond::ust::registry_event> : formatter<std::string> {
  78         template <typename FormatContextType>
  79         typename FormatContextType::iterator
  80         format(const lttng::sessiond::ust::registry_event& event, FormatContextType& ctx)
  81         {
  82                 return format_to(
  83                         ctx.out(),
  84                         "{{ name = `{}`, signature = `{}`, id = {}, session objd = {}, channel objd = {} }}",
  85                         event.name,
  86                         event.signature,
  87                         event.id,
  88                         event.session_objd,
  89                         event.channel_objd);
  90         }
  91 };
  92 } /* namespace fmt */
  93
  94 #endif /* LTTNG_UST_REGISTRY_EVENT_H */