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
  34 /*
  35  * Represents a session for the relay point of view
  36  */
  37 struct relay_session {
  38         /*
  39          * This session id is generated by the relay daemon to guarantee
  40          * its uniqueness even when serving multiple session daemons.
  41          * It is used to match a set of streams to their session.
  42          */
  43         uint64_t id;
  44         lttng_uuid sessiond_uuid;
  45         char session_name[LTTNG_NAME_MAX];
  46         char hostname[LTTNG_HOST_NAME_MAX];
  47         uint32_t live_timer;
  48
  49         /* Session in snapshot mode. */
  50         bool snapshot;
  51
  52         /*
  53          * Session has no back reference to its connection because it
  54          * has a life-time that can be longer than the consumer connection's
  55          * life-time; a reference can still be held by the viewer
  56          * connection through the viewer streams.
  57          */
  58
  59         struct urcu_ref ref;
  60
  61         pthread_mutex_t lock;
  62
  63         /* major/minor version used for this session. */
  64         uint32_t major;
  65         uint32_t minor;
  66
  67         bool viewer_attached;
  68         /* Tell if the session connection has been closed on the streaming side. */
  69         bool connection_closed;
  70
  71         /*
  72          * Tell if the session is currently living in a exiting relayd and
  73          * should be cleaned forcefully without waiting for pending data or
  74          * pending ctrl data.
  75          */
  76         bool aborted;
  77
  78         /* Contains ctf_trace object of that session indexed by path name. */
  79         struct lttng_ht *ctf_traces_ht;
  80
  81         /*
  82          * This contains streams that are received on that connection.
  83          * It's used to store them until we get the streams sent
  84          * command. When this is received, we remove those streams from
  85          * the list and publish them.
  86          *
  87          * Updates are protected by the recv_list_lock.
  88          * Traversals are protected by RCU.
  89          * recv_list_lock also protects stream_count.
  90          */
  91         struct cds_list_head recv_list; /* RCU list. */
  92         uint32_t stream_count;
  93         pthread_mutex_t recv_list_lock;
  94
  95         /*
  96          * Flag checked and exchanged with uatomic_cmpxchg to tell the
  97          * viewer-side if new streams got added since the last check.
  98          */
  99         unsigned long new_streams;
 100
 101         /*
 102          * Node in the global session hash table.
 103          */
 104         struct lttng_ht_node_u64 session_n;
 105         /*
 106          * Member of the session list in struct relay_viewer_session.
 107          * Updates are protected by the relay_viewer_session
 108          * session_list_lock. Traversals are protected by RCU.
 109          */
 110         struct cds_list_head viewer_session_node;
 111         struct lttng_trace_chunk *current_trace_chunk;
 112         struct rcu_head rcu_node;       /* For call_rcu teardown. */
 113 };
 114
 115 struct relay_session *session_create(const char *session_name,
 116                 const char *hostname, uint32_t live_timer,
 117                 bool snapshot, const lttng_uuid sessiond_uuid,
 118                 uint32_t major, uint32_t minor);
 119 struct relay_session *session_get_by_id(uint64_t id);
 120 bool session_get(struct relay_session *session);
 121 void session_put(struct relay_session *session);
 122
 123 int session_close(struct relay_session *session);
 124 int session_abort(struct relay_session *session);
 125
 126 void print_sessions(void);
 127
 128 #endif /* _SESSION_H */