2 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
3 * David Goulet <dgoulet@efficios.com>
4 * 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License, version 2 only, as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22 #include <common/common.h>
23 #include <urcu/rculist.h>
25 #include "lttng-relayd.h"
26 #include "ctf-trace.h"
30 /* Global session id used in the session creation. */
31 static uint64_t last_relay_session_id
;
32 static pthread_mutex_t last_relay_session_id_lock
= PTHREAD_MUTEX_INITIALIZER
;
35 * Create a new session by assigning a new session ID.
37 * Return allocated session or else NULL.
39 struct relay_session
*session_create(const char *session_name
,
40 const char *hostname
, uint32_t live_timer
,
41 bool snapshot
, uint32_t major
, uint32_t minor
)
43 struct relay_session
*session
;
45 session
= zmalloc(sizeof(*session
));
47 PERROR("relay session zmalloc");
50 if (lttng_strncpy(session
->session_name
, session_name
,
51 sizeof(session
->session_name
))) {
54 if (lttng_strncpy(session
->hostname
, hostname
,
55 sizeof(session
->hostname
))) {
58 session
->ctf_traces_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_STRING
);
59 if (!session
->ctf_traces_ht
) {
63 pthread_mutex_lock(&last_relay_session_id_lock
);
64 session
->id
= ++last_relay_session_id
;
65 pthread_mutex_unlock(&last_relay_session_id_lock
);
67 session
->major
= major
;
68 session
->minor
= minor
;
69 lttng_ht_node_init_u64(&session
->session_n
, session
->id
);
70 urcu_ref_init(&session
->ref
);
71 CDS_INIT_LIST_HEAD(&session
->recv_list
);
72 pthread_mutex_init(&session
->lock
, NULL
);
73 pthread_mutex_init(&session
->reflock
, NULL
);
74 pthread_mutex_init(&session
->recv_list_lock
, NULL
);
76 session
->live_timer
= live_timer
;
77 session
->snapshot
= snapshot
;
79 lttng_ht_add_unique_u64(sessions_ht
, &session
->session_n
);
87 /* Should be called with RCU read-side lock held. */
88 bool session_get(struct relay_session
*session
)
92 pthread_mutex_lock(&session
->reflock
);
93 if (session
->ref
.refcount
!= 0) {
95 urcu_ref_get(&session
->ref
);
97 pthread_mutex_unlock(&session
->reflock
);
103 * Lookup a session within the session hash table using the session id
104 * as key. A session reference is taken when a session is returned.
105 * session_put() must be called on that session.
107 * Return session or NULL if not found.
109 struct relay_session
*session_get_by_id(uint64_t id
)
111 struct relay_session
*session
= NULL
;
112 struct lttng_ht_node_u64
*node
;
113 struct lttng_ht_iter iter
;
116 lttng_ht_lookup(sessions_ht
, &id
, &iter
);
117 node
= lttng_ht_iter_get_node_u64(&iter
);
119 DBG("Session find by ID %" PRIu64
" id NOT found", id
);
122 session
= caa_container_of(node
, struct relay_session
, session_n
);
123 DBG("Session find by ID %" PRIu64
" id found", id
);
124 if (!session_get(session
)) {
132 static void rcu_destroy_session(struct rcu_head
*rcu_head
)
134 struct relay_session
*session
=
135 caa_container_of(rcu_head
, struct relay_session
,
138 * Since each trace has a reference on the session, it means
139 * that if we are at the point where we teardown the session, no
140 * trace belonging to that session exist at this point.
141 * Calling lttng_ht_destroy in call_rcu worker thread so we
142 * don't hold the RCU read-side lock while calling it.
144 lttng_ht_destroy(session
->ctf_traces_ht
);
149 * Delete session from the given hash table.
151 * Return lttng ht del error code being 0 on success and 1 on failure.
153 static int session_delete(struct relay_session
*session
)
155 struct lttng_ht_iter iter
;
157 iter
.iter
.node
= &session
->session_n
.node
;
158 return lttng_ht_del(sessions_ht
, &iter
);
162 static void destroy_session(struct relay_session
*session
)
166 ret
= session_delete(session
);
168 call_rcu(&session
->rcu_node
, rcu_destroy_session
);
171 void session_release(struct urcu_ref
*ref
)
173 struct relay_session
*session
=
174 caa_container_of(ref
, struct relay_session
, ref
);
176 destroy_session(session
);
179 void session_put(struct relay_session
*session
)
182 pthread_mutex_lock(&session
->reflock
);
183 urcu_ref_put(&session
->ref
, session_release
);
184 pthread_mutex_unlock(&session
->reflock
);
188 int session_close(struct relay_session
*session
)
191 struct ctf_trace
*trace
;
192 struct lttng_ht_iter iter
;
193 struct relay_stream
*stream
;
195 pthread_mutex_lock(&session
->lock
);
196 DBG("closing session %" PRIu64
": is conn already closed %d",
197 session
->id
, session
->connection_closed
);
198 if (session
->connection_closed
) {
202 session
->connection_closed
= true;
204 pthread_mutex_unlock(&session
->lock
);
210 cds_lfht_for_each_entry(session
->ctf_traces_ht
->ht
,
211 &iter
.iter
, trace
, node
.node
) {
212 ret
= ctf_trace_close(trace
);
217 cds_list_for_each_entry_rcu(stream
, &session
->recv_list
,
219 /* Close streams which have not been published yet. */
220 try_stream_close(stream
);
227 /* Put self-reference from create. */
228 session_put(session
);
232 void print_sessions(void)
234 struct lttng_ht_iter iter
;
235 struct relay_session
*session
;
242 cds_lfht_for_each_entry(sessions_ht
->ht
, &iter
.iter
, session
,
244 if (!session_get(session
)) {
247 DBG("session %p refcount %ld session %" PRIu64
,
249 session
->ref
.refcount
,
251 session_put(session
);