src/bin/lttng-relayd/connection.h

   1 #ifndef _CONNECTION_H
   2 #define _CONNECTION_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.h>
  27 #include <urcu/wfcqueue.h>
  28 #include <urcu/list.h>
  29
  30 #include <common/hashtable/hashtable.h>
  31 #include <common/sessiond-comm/sessiond-comm.h>
  32
  33 #include "session.h"
  34
  35 enum connection_type {
  36         RELAY_CONNECTION_UNKNOWN    = 0,
  37         RELAY_DATA                  = 1,
  38         RELAY_CONTROL               = 2,
  39         RELAY_VIEWER_COMMAND        = 3,
  40         RELAY_VIEWER_NOTIFICATION   = 4,
  41 };
  42
  43 /*
  44  * Internal structure to map a socket with the corresponding session.
  45  * A hashtable indexed on the socket FD is used for the lookups.
  46  *
  47  * Connections are assumed to be accessed from a single thread. Live
  48  * connections between the relay and a live client are only accessed
  49  * from the live worker thread.
  50  *
  51  * The connections between the consumerd/sessiond and the relayd are only
  52  * handled by the "main" worker thread (as in, the worker thread in main.c).
  53  *
  54  * This is why there are no back references to connections from the
  55  * sessions and session list.
  56  */
  57 struct relay_connection {
  58         struct lttcomm_sock *sock;
  59         struct cds_wfcq_node qnode;
  60
  61         enum connection_type type;
  62         /*
  63          * session is only ever set for RELAY_CONTROL connection type.
  64          */
  65         struct relay_session *session;
  66         /*
  67          * viewer_session is only ever set for RELAY_VIEWER_COMMAND
  68          * connection type.
  69          */
  70         struct relay_viewer_session *viewer_session;
  71
  72         /*
  73          * Protocol version to use for this connection. Only valid for
  74          * RELAY_CONTROL connection type.
  75          */
  76         uint32_t major;
  77         uint32_t minor;
  78
  79         struct urcu_ref ref;
  80         pthread_mutex_t reflock;
  81
  82         bool version_check_done;
  83
  84         /*
  85          * Node member of connection within global socket hash table.
  86          */
  87         struct lttng_ht_node_ulong sock_n;
  88         bool in_socket_ht;
  89         struct lttng_ht *socket_ht;     /* HACK: Contained within this hash table. */
  90         struct rcu_head rcu_node;       /* For call_rcu teardown. */
  91 };
  92
  93 struct relay_connection *connection_create(struct lttcomm_sock *sock,
  94                 enum connection_type type);
  95 struct relay_connection *connection_get_by_sock(struct lttng_ht *relay_connections_ht,
  96                 int sock);
  97 bool connection_get(struct relay_connection *connection);
  98 void connection_put(struct relay_connection *connection);
  99 void connection_ht_add(struct lttng_ht *relay_connections_ht,
 100                 struct relay_connection *conn);
 101
 102 #endif /* _CONNECTION_H */