src/bin/lttng-sessiond/ust-registry-channel.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_CHANNEL_H
   9 #define LTTNG_UST_REGISTRY_CHANNEL_H
  10
  11 #include "stream-class.hpp"
  12 #include "trace-class.hpp"
  13
  14 #include <common/hashtable/hashtable.hpp>
  15
  16 #include <lttng/lttng.h>
  17
  18 #include <urcu.h>
  19 #include <functional>
  20
  21 struct ust_app;
  22
  23 namespace lttng {
  24 namespace sessiond {
  25 namespace ust {
  26
  27 class registry_event;
  28
  29 class registry_channel : public lttng::sessiond::trace::stream_class {
  30 public:
  31         using registered_listener_fn = std::function<void(const registry_channel&)>;
  32         using event_added_listener_fn = std::function<void(const registry_channel&, const registry_event &)>;
  33
  34         registry_channel(uint32_t channel_id,
  35                         const lttng::sessiond::trace::abi& trace_abi,
  36                         std::string default_clock_class_name,
  37                         registered_listener_fn channel_registered_listener,
  38                         event_added_listener_fn new_event_listener);
  39         void add_event(int session_objd,
  40                         int channel_objd,
  41                         std::string name,
  42                         std::string signature,
  43                         std::vector<lttng::sessiond::trace::field::cuptr> event_fields,
  44                         int loglevel_value,
  45                         nonstd::optional<std::string> model_emf_uri,
  46                         lttng_buffer_type buffer_type,
  47                         const ust_app& app,
  48                         uint32_t& out_event_id);
  49         ~registry_channel() override;
  50         registry_channel(const registry_channel&) = delete;
  51         registry_channel(registry_channel&&) = delete;
  52         registry_channel& operator=(registry_channel&&) = delete;
  53         registry_channel& operator=(const registry_channel&) = delete;
  54
  55         const lttng::sessiond::trace::type *event_context() const final;
  56         void event_context(lttng::sessiond::trace::type::cuptr context);
  57
  58         /* Channel was registered to at least one application. */
  59         bool is_registered() const;
  60         void set_as_registered();
  61
  62         uint64_t _key;
  63         uint64_t _consumer_key;
  64
  65         /*
  66          * Hash table containing events sent by the UST tracer. MUST be accessed
  67          * with a RCU read side lock acquired.
  68          */
  69         struct lttng_ht *_events;
  70         struct lttng_ht_node_u64 _node;
  71         /* For delayed reclaim */
  72         struct rcu_head _rcu_head;
  73         /* Once this value reaches UINT32_MAX, no more id can be allocated. */
  74         uint32_t _next_event_id;
  75
  76 private:
  77         void _accept_on_event_classes(
  78                         lttng::sessiond::trace::trace_class_visitor& trace_class_visitor) const final;
  79
  80         registered_listener_fn _is_registered_listener;
  81         event_added_listener_fn _event_added_listener;
  82         /* Indicates if this channel registry has already been registered. */
  83         bool _is_registered;
  84 };
  85
  86 } /* namespace ust */
  87 } /* namespace sessiond */
  88 } /* namespace lttng */
  89
  90 #endif /* LTTNG_UST_REGISTRY_CHANNEL_H */