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