Commit | Line | Data |
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d3e2ba59 JD |
1 | /* |
2 | * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com> | |
3 | * David Goulet <dgoulet@efficios.com> | |
7591bab1 | 4 | * 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
d3e2ba59 JD |
5 | * |
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. | |
9 | * | |
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 | |
13 | * more details. | |
14 | * | |
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. | |
18 | */ | |
19 | ||
20 | #define _GNU_SOURCE | |
6c1c0768 | 21 | #define _LGPL_SOURCE |
d3e2ba59 JD |
22 | #include <assert.h> |
23 | ||
24 | #include <common/common.h> | |
25 | #include <common/utils.h> | |
7591bab1 | 26 | #include <urcu/rculist.h> |
d3e2ba59 JD |
27 | |
28 | #include "ctf-trace.h" | |
2a174661 DG |
29 | #include "lttng-relayd.h" |
30 | #include "stream.h" | |
d3e2ba59 JD |
31 | |
32 | static uint64_t last_relay_ctf_trace_id; | |
7591bab1 | 33 | static pthread_mutex_t last_relay_ctf_trace_id_lock = PTHREAD_MUTEX_INITIALIZER; |
d3e2ba59 | 34 | |
7591bab1 | 35 | static void rcu_destroy_ctf_trace(struct rcu_head *rcu_head) |
2a174661 | 36 | { |
7591bab1 MD |
37 | struct ctf_trace *trace = |
38 | caa_container_of(rcu_head, struct ctf_trace, rcu_node); | |
2a174661 DG |
39 | |
40 | free(trace); | |
41 | } | |
42 | ||
d3e2ba59 | 43 | /* |
2a174661 DG |
44 | * Destroy a ctf trace and all stream contained in it. |
45 | * | |
46 | * MUST be called with the RCU read side lock. | |
d3e2ba59 | 47 | */ |
7591bab1 | 48 | void ctf_trace_destroy(struct ctf_trace *trace) |
d3e2ba59 | 49 | { |
2a174661 | 50 | /* |
7591bab1 MD |
51 | * Getting to this point, every stream referenced by that trace |
52 | * have put back their ref since the've been closed by the | |
53 | * control side. | |
2a174661 | 54 | */ |
7591bab1 MD |
55 | assert(cds_list_empty(&trace->stream_list)); |
56 | session_put(trace->session); | |
57 | trace->session = NULL; | |
58 | call_rcu(&trace->rcu_node, rcu_destroy_ctf_trace); | |
59 | } | |
2a174661 | 60 | |
7591bab1 MD |
61 | void ctf_trace_release(struct urcu_ref *ref) |
62 | { | |
63 | struct ctf_trace *trace = | |
64 | caa_container_of(ref, struct ctf_trace, ref); | |
65 | int ret; | |
66 | struct lttng_ht_iter iter; | |
d3e2ba59 | 67 | |
7591bab1 MD |
68 | iter.iter.node = &trace->node.node; |
69 | ret = lttng_ht_del(trace->session->ctf_traces_ht, &iter); | |
70 | assert(!ret); | |
71 | ctf_trace_destroy(trace); | |
2a174661 DG |
72 | } |
73 | ||
7591bab1 MD |
74 | /* |
75 | * Should be called with RCU read-side lock held. | |
76 | */ | |
77 | bool ctf_trace_get(struct ctf_trace *trace) | |
2a174661 | 78 | { |
7591bab1 | 79 | bool has_ref = false; |
2a174661 | 80 | |
7591bab1 MD |
81 | /* Confirm that the trace refcount has not reached 0. */ |
82 | pthread_mutex_lock(&trace->reflock); | |
83 | if (trace->ref.refcount != 0) { | |
84 | has_ref = true; | |
85 | urcu_ref_get(&trace->ref); | |
d3e2ba59 | 86 | } |
7591bab1 MD |
87 | pthread_mutex_unlock(&trace->reflock); |
88 | ||
89 | return has_ref; | |
d3e2ba59 JD |
90 | } |
91 | ||
92 | /* | |
7591bab1 MD |
93 | * Create and return an allocated ctf_trace. NULL on error. |
94 | * There is no "open" and "close" for a ctf_trace, but rather just a | |
95 | * create and refcounting. Whenever all the streams belonging to a trace | |
96 | * put their reference, its refcount drops to 0. | |
d3e2ba59 | 97 | */ |
7591bab1 MD |
98 | static struct ctf_trace *ctf_trace_create(struct relay_session *session, |
99 | char *path_name) | |
d3e2ba59 | 100 | { |
7591bab1 | 101 | struct ctf_trace *trace; |
d3e2ba59 | 102 | |
7591bab1 MD |
103 | trace = zmalloc(sizeof(*trace)); |
104 | if (!trace) { | |
d3e2ba59 JD |
105 | PERROR("ctf_trace alloc"); |
106 | goto error; | |
107 | } | |
108 | ||
7591bab1 MD |
109 | if (!session_get(session)) { |
110 | ERR("Cannot get session"); | |
111 | free(trace); | |
112 | trace = NULL; | |
113 | goto error; | |
114 | } | |
115 | trace->session = session; | |
116 | ||
117 | CDS_INIT_LIST_HEAD(&trace->stream_list); | |
118 | ||
119 | pthread_mutex_lock(&last_relay_ctf_trace_id_lock); | |
120 | trace->id = ++last_relay_ctf_trace_id; | |
121 | pthread_mutex_unlock(&last_relay_ctf_trace_id_lock); | |
2a174661 | 122 | |
7591bab1 MD |
123 | lttng_ht_node_init_str(&trace->node, path_name); |
124 | trace->session = session; | |
125 | urcu_ref_init(&trace->ref); | |
126 | pthread_mutex_init(&trace->lock, NULL); | |
127 | pthread_mutex_init(&trace->reflock, NULL); | |
128 | pthread_mutex_init(&trace->stream_list_lock, NULL); | |
129 | lttng_ht_add_str(session->ctf_traces_ht, &trace->node); | |
2a174661 | 130 | |
7591bab1 | 131 | DBG("Created ctf_trace %" PRIu64 " with path: %s", trace->id, path_name); |
d3e2ba59 JD |
132 | |
133 | error: | |
7591bab1 | 134 | return trace; |
d3e2ba59 JD |
135 | } |
136 | ||
137 | /* | |
7591bab1 MD |
138 | * Return a ctf_trace if found by id in the given hash table else NULL. |
139 | * Hold a reference on the ctf_trace, and must be paired with | |
140 | * ctf_trace_put(). | |
d3e2ba59 | 141 | */ |
7591bab1 | 142 | struct ctf_trace *ctf_trace_get_by_path_or_create(struct relay_session *session, |
2a174661 | 143 | char *path_name) |
d3e2ba59 | 144 | { |
2a174661 | 145 | struct lttng_ht_node_str *node; |
d3e2ba59 | 146 | struct lttng_ht_iter iter; |
2a174661 | 147 | struct ctf_trace *trace = NULL; |
d3e2ba59 | 148 | |
7591bab1 MD |
149 | rcu_read_lock(); |
150 | lttng_ht_lookup(session->ctf_traces_ht, (void *) path_name, &iter); | |
2a174661 DG |
151 | node = lttng_ht_iter_get_node_str(&iter); |
152 | if (!node) { | |
153 | DBG("CTF Trace path %s not found", path_name); | |
154 | goto end; | |
d3e2ba59 | 155 | } |
2a174661 | 156 | trace = caa_container_of(node, struct ctf_trace, node); |
7591bab1 MD |
157 | if (!ctf_trace_get(trace)) { |
158 | trace = NULL; | |
159 | } | |
d3e2ba59 | 160 | end: |
7591bab1 MD |
161 | rcu_read_unlock(); |
162 | if (!trace) { | |
163 | /* Try to create */ | |
164 | trace = ctf_trace_create(session, path_name); | |
165 | } | |
2a174661 | 166 | return trace; |
d3e2ba59 JD |
167 | } |
168 | ||
7591bab1 | 169 | void ctf_trace_put(struct ctf_trace *trace) |
2a174661 | 170 | { |
7591bab1 MD |
171 | rcu_read_lock(); |
172 | pthread_mutex_lock(&trace->reflock); | |
173 | urcu_ref_put(&trace->ref, ctf_trace_release); | |
174 | pthread_mutex_unlock(&trace->reflock); | |
175 | rcu_read_unlock(); | |
2a174661 DG |
176 | } |
177 | ||
7591bab1 | 178 | int ctf_trace_close(struct ctf_trace *trace) |
2a174661 | 179 | { |
7591bab1 MD |
180 | struct relay_stream *stream; |
181 | ||
182 | rcu_read_lock(); | |
183 | cds_list_for_each_entry_rcu(stream, &trace->stream_list, | |
184 | stream_node) { | |
185 | /* | |
186 | * Close the stream. | |
187 | */ | |
188 | stream_close(stream); | |
189 | } | |
190 | rcu_read_unlock(); | |
191 | /* | |
192 | * Since all references to the trace are held by its streams, we | |
193 | * don't need to do any self-ref put. | |
194 | */ | |
195 | return 0; | |
196 | } | |
2a174661 | 197 | |
7591bab1 MD |
198 | struct relay_viewer_stream *ctf_trace_get_viewer_metadata_stream(struct ctf_trace *trace) |
199 | { | |
200 | struct relay_viewer_stream *vstream; | |
2a174661 | 201 | |
7591bab1 MD |
202 | rcu_read_lock(); |
203 | vstream = rcu_dereference(trace->viewer_metadata_stream); | |
204 | if (!vstream) { | |
205 | goto end; | |
206 | } | |
207 | if (!viewer_stream_get(vstream)) { | |
208 | vstream = NULL; | |
209 | } | |
210 | end: | |
211 | rcu_read_unlock(); | |
212 | return vstream; | |
2a174661 | 213 | } |