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
  13 #include <common/hashtable/hashtable.hpp>
  14
  15 #include <lttng/lttng.h>
  16
  17 #include <urcu.h>
  18 #include <functional>
  19
  20 struct ust_app;
  21
  22 namespace lttng {
  23 namespace sessiond {
  24 namespace ust {
  25
  26 class registry_event;
  27
  28 class registry_channel : public lttng::sessiond::trace::stream_class {
  29 public:
  30         using registered_listener_fn = std::function<void(const registry_channel&)>;
  31         using event_added_listener_fn = std::function<void(const registry_channel&, const registry_event &)>;
  32
  33         registry_channel(uint32_t channel_id,
  34                         registered_listener_fn channel_registered_listener,
  35                         event_added_listener_fn new_event_listener);
  36         void add_event(int session_objd,
  37                         int channel_objd,
  38                         std::string name,
  39                         std::string signature,
  40                         std::vector<lttng::sessiond::trace::field::cuptr> event_fields,
  41                         int loglevel_value,
  42                         nonstd::optional<std::string> model_emf_uri,
  43                         lttng_buffer_type buffer_type,
  44                         const ust_app& app,
  45                         uint32_t& out_event_id);
  46         virtual ~registry_channel();
  47
  48         virtual const lttng::sessiond::trace::type& get_context() const override final;
  49         void set_context(lttng::sessiond::trace::type::cuptr context);
  50
  51         /* Channel was registered to at least one application. */
  52         bool is_registered() const;
  53         void set_as_registered();
  54
  55         uint64_t _key;
  56         uint64_t _consumer_key;
  57
  58         /*
  59          * Flag for this channel if the metadata was dumped once during
  60          * registration. 0 means no, 1 yes.
  61          */
  62         unsigned int _metadata_dumped;
  63
  64         /*
  65          * Hash table containing events sent by the UST tracer. MUST be accessed
  66          * with a RCU read side lock acquired.
  67          */
  68         struct lttng_ht *_events;
  69         struct lttng_ht_node_u64 _node;
  70         /* For delayed reclaim */
  71         struct rcu_head _rcu_head;
  72         /* Once this value reaches UINT32_MAX, no more id can be allocated. */
  73         uint32_t _next_event_id;
  74
  75 private:
  76         virtual void _accept_on_event_classes(
  77                         lttng::sessiond::trace::trace_class_visitor& trace_class_visitor) const override final;
  78
  79         registered_listener_fn _is_registered_listener;
  80         event_added_listener_fn _event_added_listener;
  81         /* Indicates if this channel registry has already been registered. */
  82         bool _is_registered;
  83 };
  84
  85 } /* namespace ust */
  86 } /* namespace sessiond */
  87 } /* namespace lttng */
  88
  89 #endif /* LTTNG_UST_REGISTRY_CHANNEL_H */