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         virtual ~registry_channel();
  50
  51         virtual const lttng::sessiond::trace::type *get_event_context() const override final;
  52         void set_event_context(lttng::sessiond::trace::type::cuptr context);
  53
  54         /* Channel was registered to at least one application. */
  55         bool is_registered() const;
  56         void set_as_registered();
  57
  58         uint64_t _key;
  59         uint64_t _consumer_key;
  60
  61         /*
  62          * Hash table containing events sent by the UST tracer. MUST be accessed
  63          * with a RCU read side lock acquired.
  64          */
  65         struct lttng_ht *_events;
  66         struct lttng_ht_node_u64 _node;
  67         /* For delayed reclaim */
  68         struct rcu_head _rcu_head;
  69         /* Once this value reaches UINT32_MAX, no more id can be allocated. */
  70         uint32_t _next_event_id;
  71
  72 private:
  73         virtual void _accept_on_event_classes(
  74                         lttng::sessiond::trace::trace_class_visitor& trace_class_visitor) const override final;
  75
  76         registered_listener_fn _is_registered_listener;
  77         event_added_listener_fn _event_added_listener;
  78         /* Indicates if this channel registry has already been registered. */
  79         bool _is_registered;
  80 };
  81
  82 } /* namespace ust */
  83 } /* namespace sessiond */
  84 } /* namespace lttng */
  85
  86 #endif /* LTTNG_UST_REGISTRY_CHANNEL_H */