src/bin/lttng-relayd/session.h

   1 #ifndef _SESSION_H
   2 #define _SESSION_H
   3
   4 /*
   5  * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
   6  *                      David Goulet <dgoulet@efficios.com>
   7  *               2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License, version 2 only, as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  16  * more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along with
  19  * this program; if not, write to the Free Software Foundation, Inc., 51
  20  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #include <limits.h>
  24 #include <inttypes.h>
  25 #include <pthread.h>
  26 #include <urcu/list.h>
  27 #include <urcu/ref.h>
  28
  29 #include <lttng/constant.h>
  30 #include <common/hashtable/hashtable.h>
  31 #include <common/compat/uuid.h>
  32 #include <common/trace-chunk.h>
  33 #include <common/optional.h>
  34
  35 /*
  36  * Represents a session for the relay point of view
  37  */
  38 struct relay_session {
  39         /*
  40          * This session id is generated by the relay daemon to guarantee
  41          * its uniqueness even when serving multiple session daemons.
  42          * It is used to match a set of streams to their session.
  43          */
  44         uint64_t id;
  45         /*
  46          * ID of the session in the session daemon's domain.
  47          * This information is only provided by 2.11+ peers.
  48          */
  49         LTTNG_OPTIONAL(uint64_t) id_sessiond;
  50         /*
  51          * Only provided by 2.11+ peers. However, the UUID is set to 'nil' in
  52          * the other cases.
  53          */
  54         lttng_uuid sessiond_uuid;
  55         LTTNG_OPTIONAL(time_t) creation_time;
  56         char session_name[LTTNG_NAME_MAX];
  57         char hostname[LTTNG_HOST_NAME_MAX];
  58         char base_path[LTTNG_PATH_MAX];
  59         uint32_t live_timer;
  60
  61         /* Session in snapshot mode. */
  62         bool snapshot;
  63
  64         /*
  65          * Session has no back reference to its connection because it
  66          * has a life-time that can be longer than the consumer connection's
  67          * life-time; a reference can still be held by the viewer
  68          * connection through the viewer streams.
  69          */
  70
  71         struct urcu_ref ref;
  72
  73         pthread_mutex_t lock;
  74
  75         /* major/minor version used for this session. */
  76         uint32_t major;
  77         uint32_t minor;
  78
  79         bool viewer_attached;
  80         /* Tell if the session connection has been closed on the streaming side. */
  81         bool connection_closed;
  82
  83         /*
  84          * Tell if the session is currently living in a exiting relayd and
  85          * should be cleaned forcefully without waiting for pending data or
  86          * pending ctrl data.
  87          */
  88         bool aborted;
  89
  90         bool session_name_contains_creation_time;
  91
  92         /* Contains ctf_trace object of that session indexed by path name. */
  93         struct lttng_ht *ctf_traces_ht;
  94
  95         /*
  96          * This contains streams that are received on that connection.
  97          * It's used to store them until we get the streams sent
  98          * command. When this is received, we remove those streams from
  99          * the list and publish them.
 100          *
 101          * Updates are protected by the recv_list_lock.
 102          * Traversals are protected by RCU.
 103          * recv_list_lock also protects stream_count.
 104          */
 105         struct cds_list_head recv_list; /* RCU list. */
 106         uint32_t stream_count;
 107         pthread_mutex_t recv_list_lock;
 108
 109         /*
 110          * Flag checked and exchanged with uatomic_cmpxchg to tell the
 111          * viewer-side if new streams got added since the last check.
 112          */
 113         unsigned long new_streams;
 114
 115         /*
 116          * Node in the global session hash table.
 117          */
 118         struct lttng_ht_node_u64 session_n;
 119         /*
 120          * Member of the session list in struct relay_viewer_session.
 121          * Updates are protected by the relay_viewer_session
 122          * session_list_lock. Traversals are protected by RCU.
 123          */
 124         struct cds_list_head viewer_session_node;
 125         struct lttng_trace_chunk *current_trace_chunk;
 126         struct lttng_trace_chunk *pending_closure_trace_chunk;
 127         struct rcu_head rcu_node;       /* For call_rcu teardown. */
 128 };
 129
 130 struct relay_session *session_create(const char *session_name,
 131                 const char *hostname, const char *base_path,
 132                 uint32_t live_timer,
 133                 bool snapshot,
 134                 const lttng_uuid sessiond_uuid,
 135                 const uint64_t *id_sessiond,
 136                 const uint64_t *current_chunk_id,
 137                 const time_t *creation_time,
 138                 uint32_t major,
 139                 uint32_t minor,
 140                 bool session_name_contains_creation_timestamp);
 141 struct relay_session *session_get_by_id(uint64_t id);
 142 bool session_get(struct relay_session *session);
 143 void session_put(struct relay_session *session);
 144
 145 int session_close(struct relay_session *session);
 146 int session_abort(struct relay_session *session);
 147
 148 void print_sessions(void);
 149
 150 #endif /* _SESSION_H */