src/bin/lttng-relayd/session.h

   1 /*
   2  * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
   3  *                      David Goulet <dgoulet@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License, version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 51
  16  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #ifndef _SESSION_H
  20 #define _SESSION_H
  21
  22 #include <limits.h>
  23 #include <inttypes.h>
  24 #include <pthread.h>
  25
  26 #include <common/hashtable/hashtable.h>
  27
  28 /*
  29  * Represents a session for the relay point of view
  30  */
  31 struct relay_session {
  32         /*
  33          * This session id is used to identify a set of stream to a tracing session
  34          * but also make sure we have a unique session id associated with a session
  35          * daemon which can provide multiple data source.
  36          */
  37         uint64_t id;
  38         struct lttcomm_sock *sock;
  39         char session_name[NAME_MAX];
  40         char hostname[HOST_NAME_MAX];
  41         uint32_t live_timer;
  42         struct lttng_ht_node_ulong session_n;
  43         struct rcu_head rcu_node;
  44         uint32_t viewer_attached;
  45         uint32_t stream_count;
  46         /* Tell if this session is for a snapshot or not. */
  47         unsigned int snapshot:1;
  48
  49         /*
  50          * Indicate version protocol for this session. This is especially useful
  51          * for the data thread that has no idea which version it operates on since
  52          * linking control/data sockets is non trivial.
  53          */
  54         uint64_t minor;
  55         uint64_t major;
  56         /*
  57          * Flag checked and exchanged with uatomic_cmpxchg to tell the
  58          * viewer-side if new streams got added since the last check.
  59          */
  60         unsigned long new_streams;
  61
  62         /*
  63          * Used to synchronize the process where we flag every streams readiness
  64          * for the viewer when the streams_sent message is received and the viewer
  65          * process of sending those streams.
  66          */
  67         pthread_mutex_t viewer_ready_lock;
  68 };
  69
  70 struct relay_session *session_find_by_id(struct lttng_ht *ht, uint64_t id);
  71
  72 #endif /* _SESSION_H */