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/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         /* Must _not_ be empty for 2.4+ peers. */
  57         char session_name[LTTNG_NAME_MAX];
  58         char hostname[LTTNG_HOST_NAME_MAX];
  59         char base_path[LTTNG_PATH_MAX];
  60         /*
  61          * Session output path relative to relayd's output path.
  62          * Will be empty when interacting with peers < 2.11 since their
  63          * streams' path are expressed relative to the relay daemon's
  64          * output path.
  65          */
  66         char output_path[LTTNG_PATH_MAX];
  67         uint32_t live_timer;
  68
  69         /* Session in snapshot mode. */
  70         bool snapshot;
  71
  72         /*
  73          * Session has no back reference to its connection because it
  74          * has a life-time that can be longer than the consumer connection's
  75          * life-time; a reference can still be held by the viewer
  76          * connection through the viewer streams.
  77          */
  78
  79         struct urcu_ref ref;
  80
  81         pthread_mutex_t lock;
  82
  83         /* major/minor version used for this session. */
  84         uint32_t major;
  85         uint32_t minor;
  86
  87         bool viewer_attached;
  88         /* Tell if the session connection has been closed on the streaming side. */
  89         bool connection_closed;
  90
  91         /*
  92          * Tell if the session is currently living in a exiting relayd and
  93          * should be cleaned forcefully without waiting for pending data or
  94          * pending ctrl data.
  95          */
  96         bool aborted;
  97
  98         bool session_name_contains_creation_time;
  99         /* Whether session has performed an explicit rotation. */
 100         bool has_rotated;
 101
 102         /* Contains ctf_trace object of that session indexed by path name. */
 103         struct lttng_ht *ctf_traces_ht;
 104
 105         /*
 106          * This contains streams that are received on that connection.
 107          * It's used to store them until we get the streams sent
 108          * command. When this is received, we remove those streams from
 109          * the list and publish them.
 110          *
 111          * Updates are protected by the recv_list_lock.
 112          * Traversals are protected by RCU.
 113          * recv_list_lock also protects stream_count.
 114          */
 115         struct cds_list_head recv_list; /* RCU list. */
 116         uint32_t stream_count;
 117         pthread_mutex_t recv_list_lock;
 118
 119         /*
 120          * Flag checked and exchanged with uatomic_cmpxchg to tell the
 121          * viewer-side if new streams got added since the last check.
 122          */
 123         unsigned long new_streams;
 124
 125         /*
 126          * Node in the global session hash table.
 127          */
 128         struct lttng_ht_node_u64 session_n;
 129         /*
 130          * Member of the session list in struct relay_viewer_session.
 131          * Updates are protected by the relay_viewer_session
 132          * session_list_lock. Traversals are protected by RCU.
 133          */
 134         struct cds_list_head viewer_session_node;
 135         struct lttng_trace_chunk *current_trace_chunk;
 136         struct lttng_trace_chunk *pending_closure_trace_chunk;
 137         struct rcu_head rcu_node;       /* For call_rcu teardown. */
 138 };
 139
 140 struct relay_session *session_create(const char *session_name,
 141                 const char *hostname, const char *base_path,
 142                 uint32_t live_timer,
 143                 bool snapshot,
 144                 const lttng_uuid sessiond_uuid,
 145                 const uint64_t *id_sessiond,
 146                 const uint64_t *current_chunk_id,
 147                 const time_t *creation_time,
 148                 uint32_t major,
 149                 uint32_t minor,
 150                 bool session_name_contains_creation_timestamp);
 151 struct relay_session *session_get_by_id(uint64_t id);
 152 bool session_get(struct relay_session *session);
 153 void session_put(struct relay_session *session);
 154
 155 int session_close(struct relay_session *session);
 156 int session_abort(struct relay_session *session);
 157
 158 struct lttng_directory_handle *session_create_output_directory_handle(
 159                 struct relay_session *session);
 160
 161 void print_sessions(void);
 162
 163 #endif /* _SESSION_H */