-class ust_registry_session;
-
-namespace lttng {
-namespace sessiond {
-namespace details {
-void locked_ust_registry_session_release(ust_registry_session *session);
-} /* namespace details */
-} /* namespace sessiond */
-} /* namespace lttng */
-
-class ust_registry_session : public lttng::sessiond::trace::trace_class {
-public:
- using locked_ptr = std::unique_ptr<ust_registry_session,
- lttng::details::create_unique_class<ust_registry_session,
- lttng::sessiond::details::locked_ust_registry_session_release>::
- deleter>;
-
- virtual lttng_buffer_type get_buffering_scheme() const noexcept = 0;
- locked_ptr lock();
-
- void add_channel(uint64_t channel_key);
- lttng::sessiond::ust::registry_channel& get_channel(uint64_t channel_key) const;
- void remove_channel(uint64_t channel_key, bool notify);
-
- void regenerate_metadata();
- virtual ~ust_registry_session();
-
- /*
- * With multiple writers and readers, use this lock to access
- * the registry. Can nest within the ust app session lock.
- * Also acts as a registry serialization lock. Used by registry
- * readers to serialize the registry information sent from the
- * sessiond to the consumerd.
- * The consumer socket lock nests within this lock.
- */
- mutable pthread_mutex_t _lock;
- /* Next channel ID available for a newly registered channel. */
- uint32_t _next_channel_id = 0;
- /* Once this value reaches UINT32_MAX, no more id can be allocated. */
- uint32_t _used_channel_id = 0;
- /* Next enumeration ID available. */
- uint64_t _next_enum_id = 0;
-
- /* Generated metadata. */
- char *_metadata = nullptr; /* NOT null-terminated ! Use memcpy. */
- size_t _metadata_len = 0, _metadata_alloc_len = 0;
- /* Length of bytes sent to the consumer. */
- size_t _metadata_len_sent = 0;
- /* Current version of the metadata. */
- uint64_t _metadata_version = 0;
-
- /*
- * Those fields are only used when a session is created with
- * the --shm-path option. In this case, the metadata is output
- * twice: once to the consumer, as ususal, but a second time
- * also in the shm path directly. This is done so that a copy
- * of the metadata that is as fresh as possible is available
- * on the event of a crash.
- *
- * root_shm_path contains the shm-path provided by the user, along with
- * the session's name and timestamp:
- * e.g. /tmp/my_shm/my_session-20180612-135822
- *
- * shm_path contains the full path of the memory buffers:
- * e.g. /tmp/my_shm/my_session-20180612-135822/ust/uid/1000/64-bit
- *
- * metadata_path contains the full path to the metadata file that
- * is kept for the "crash buffer" extraction:
- * e.g.
- * /tmp/my_shm/my_session-20180612-135822/ust/uid/1000/64-bit/metadata
- *
- * Note that this is not the trace's final metadata file. It is
- * only meant to be used to read the contents of the ring buffers
- * in the event of a crash.
- *
- * metadata_fd is a file descriptor that points to the file at
- * 'metadata_path'.
- */
- char _root_shm_path[PATH_MAX] = {};
- char _shm_path[PATH_MAX] = {};
- char _metadata_path[PATH_MAX] = {};
- /* File-backed metadata FD */
- int _metadata_fd = -1;
-
- /*
- * Hash table containing channels sent by the UST tracer. MUST
- * be accessed with a RCU read side lock acquired.
- */
- lttng_ht::uptr _channels;
-
- /*
- * Unique key to identify the metadata on the consumer side.
- */
- uint64_t _metadata_key = 0;
- /*
- * Indicates if the metadata is closed on the consumer side. This is to
- * avoid double close of metadata when an application unregisters AND
- * deletes its sessions.
- */
- bool _metadata_closed = false;
-
- /* User and group owning the session. */
- uid_t _uid = -1;
- gid_t _gid = -1;
-
- /* Enumerations table. */
- lttng_ht::uptr _enums;
-
- /*
- * Copy of the tracer version when the first app is registered.
- * It is used if we need to regenerate the metadata.
- */
- uint32_t _app_tracer_version_major = 0;
- uint32_t _app_tracer_version_minor = 0;
-
- /* The id of the parent session */
- ltt_session::id_t _tracing_id = -1ULL;
-
-protected:
- /* Prevent instanciation of this base class. */
- ust_registry_session(const struct lttng::sessiond::trace::abi& abi,
- unsigned int app_tracer_version_major,
- unsigned int app_tracer_version_minor,
- const char *root_shm_path,
- const char *shm_path,
- uid_t euid,
- gid_t egid,
- uint64_t tracing_id);
- virtual void _visit_environment(
- lttng::sessiond::trace::trace_class_visitor& trace_class_visitor)
- const override;
- void _generate_metadata();
-
-private:
- uint32_t _get_next_channel_id();
- void _increase_metadata_size(size_t reservation_length);
- void _append_metadata_fragment(const std::string& fragment);
- void _reset_metadata();
-
- virtual void _accept_on_clock_classes(
- lttng::sessiond::trace::trace_class_visitor& trace_class_visitor)
- const override final;
- virtual void _accept_on_stream_classes(
- lttng::sessiond::trace::trace_class_visitor& trace_class_visitor)
- const override final;
-
- lttng::sessiond::ust::clock_class _clock;
- const lttng::sessiond::trace::trace_class_visitor::cuptr _metadata_generating_visitor;
-};
-
-class ust_registry_session_per_uid : public ust_registry_session {
-public:
- ust_registry_session_per_uid(const struct lttng::sessiond::trace::abi& trace_abi,
- uint32_t major,
- uint32_t minor,
- const char *root_shm_path,
- const char *shm_path,
- uid_t euid,
- gid_t egid,
- uint64_t tracing_id,
- uid_t tracing_uid);
-
- virtual lttng_buffer_type get_buffering_scheme() const noexcept override final;
-
-private:
- virtual void _visit_environment(
- lttng::sessiond::trace::trace_class_visitor& trace_class_visitor)
- const override final;
-
- const uid_t _tracing_uid;
-};
-
-class ust_registry_session_per_pid : public ust_registry_session {
-public:
- ust_registry_session_per_pid(const struct ust_app& app,
- const struct lttng::sessiond::trace::abi&
- trace_abi,
- uint32_t major,
- uint32_t minor,
- const char *root_shm_path,
- const char *shm_path,
- uid_t euid,
- gid_t egid,
- uint64_t tracing_id);
-
- virtual lttng_buffer_type get_buffering_scheme() const noexcept override final;
-
-private:
- virtual void _visit_environment(
- lttng::sessiond::trace::trace_class_visitor& trace_class_visitor)
- const override final;
-
- const unsigned int _tracer_patch_level_version;
- const pid_t _vpid;
- const std::string _procname;
- const std::time_t _app_creation_time;
-};
-