src/bin/lttng-relayd/session.hpp

   1 #ifndef _SESSION_H
   2 #define _SESSION_H
   3
   4 /*
   5  * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
   6  * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
   7  * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-only
  10  *
  11  */
  12
  13 #include <common/hashtable/hashtable.hpp>
  14 #include <common/optional.hpp>
  15 #include <common/trace-chunk.hpp>
  16 #include <common/uuid.hpp>
  17
  18 #include <lttng/constant.h>
  19
  20 #include <inttypes.h>
  21 #include <limits.h>
  22 #include <pthread.h>
  23 #include <urcu/list.h>
  24 #include <urcu/ref.h>
  25
  26 /*
  27  * Represents a session for the relay point of view
  28  */
  29 struct relay_session {
  30         /*
  31          * This session id is generated by the relay daemon to guarantee
  32          * its uniqueness even when serving multiple session daemons.
  33          * It is used to match a set of streams to their session.
  34          */
  35         uint64_t id;
  36         /*
  37          * ID of the session in the session daemon's domain.
  38          * This information is only provided by 2.11+ peers.
  39          */
  40         LTTNG_OPTIONAL(uint64_t) id_sessiond;
  41         /*
  42          * Only provided by 2.11+ peers. However, the UUID is set to 'nil' in
  43          * the other cases.
  44          */
  45         lttng_uuid sessiond_uuid;
  46         /*
  47          * Contains the creation time on the session daemon's end for 2.11+
  48          * peers. Otherwise, this contains the session creation time on the
  49          * relay daemon's end.
  50          */
  51         LTTNG_OPTIONAL(time_t) creation_time;
  52         /* Must _not_ be empty for 2.4+ peers. */
  53         char session_name[LTTNG_NAME_MAX];
  54         char hostname[LTTNG_HOST_NAME_MAX];
  55         char base_path[LTTNG_PATH_MAX];
  56         /*
  57          * Session output path relative to relayd's output path.
  58          * Will be empty when interacting with peers < 2.11 since their
  59          * streams' path are expressed relative to the relay daemon's
  60          * output path.
  61          */
  62         char output_path[LTTNG_PATH_MAX];
  63         uint32_t live_timer;
  64
  65         /* Session in snapshot mode. */
  66         bool snapshot;
  67
  68         /*
  69          * Session has no back reference to its connection because it
  70          * has a life-time that can be longer than the consumer connection's
  71          * life-time; a reference can still be held by the viewer
  72          * connection through the viewer streams.
  73          */
  74
  75         struct urcu_ref ref;
  76
  77         mutable pthread_mutex_t lock;
  78
  79         /* major/minor version used for this session. */
  80         uint32_t major;
  81         uint32_t minor;
  82
  83         bool viewer_attached;
  84         /* Tell if the session connection has been closed on the streaming side. */
  85         bool connection_closed;
  86
  87         /*
  88          * Tell if the session is currently living in a exiting relayd and
  89          * should be cleaned forcefully without waiting for pending data or
  90          * pending ctrl data.
  91          */
  92         bool aborted;
  93
  94         bool session_name_contains_creation_time;
  95         /* Whether session has performed an explicit rotation. */
  96         bool has_rotated;
  97
  98         /* Contains ctf_trace object of that session indexed by path name. */
  99         struct lttng_ht *ctf_traces_ht;
 100
 101         /*
 102          * This contains streams that are received on that connection.
 103          * It's used to store them until we get the streams sent
 104          * command. When this is received, we remove those streams from
 105          * the list and publish them.
 106          *
 107          * Updates are protected by the recv_list_lock.
 108          * Traversals are protected by RCU.
 109          * recv_list_lock also protects stream_count.
 110          */
 111         struct cds_list_head recv_list; /* RCU list. */
 112         uint32_t stream_count;
 113         pthread_mutex_t recv_list_lock;
 114
 115         /*
 116          * Flag checked and exchanged with uatomic_cmpxchg to tell the
 117          * viewer-side if new streams got added since the last check.
 118          */
 119         unsigned long new_streams;
 120
 121         /*
 122          * Node in the global session hash table.
 123          */
 124         struct lttng_ht_node_u64 session_n;
 125         /*
 126          * Member of the session list in struct relay_viewer_session.
 127          * Updates are protected by the relay_viewer_session
 128          * session_list_lock. Traversals are protected by RCU.
 129          */
 130         struct cds_list_head viewer_session_node;
 131         struct lttng_trace_chunk *current_trace_chunk;
 132         struct lttng_trace_chunk *pending_closure_trace_chunk;
 133         /*
 134          * Prevent live viewers from taking of copy of the chunk
 135          * while new chunk has a temporary directory name.
 136          */
 137         bool ongoing_rotation;
 138         struct lttng_directory_handle *output_directory;
 139         struct rcu_head rcu_node; /* For call_rcu teardown. */
 140 };
 141
 142 struct relay_session *session_create(const char *session_name,
 143                                      const char *hostname,
 144                                      const char *base_path,
 145                                      uint32_t live_timer,
 146                                      bool snapshot,
 147                                      const lttng_uuid& sessiond_uuid,
 148                                      const uint64_t *id_sessiond,
 149                                      const uint64_t *current_chunk_id,
 150                                      const time_t *creation_time,
 151                                      uint32_t major,
 152                                      uint32_t minor,
 153                                      bool session_name_contains_creation_timestamp);
 154 struct relay_session *session_get_by_id(uint64_t id);
 155 bool session_get(struct relay_session *session);
 156 void session_put(struct relay_session *session);
 157
 158 int session_close(struct relay_session *session);
 159 int session_abort(struct relay_session *session);
 160
 161 bool session_has_ongoing_rotation(const struct relay_session *session);
 162
 163 void print_sessions();
 164
 165 #endif /* _SESSION_H */