Fix: ensure a newline is printed before exit on client destroy
[lttng-tools.git] / src / bin / lttng-relayd / ctf-trace.c
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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>
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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
6c1c0768 20#define _LGPL_SOURCE
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21#include <assert.h>
22
23#include <common/common.h>
24#include <common/utils.h>
7591bab1 25#include <urcu/rculist.h>
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26
27#include "ctf-trace.h"
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28#include "lttng-relayd.h"
29#include "stream.h"
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30
31static uint64_t last_relay_ctf_trace_id;
7591bab1 32static pthread_mutex_t last_relay_ctf_trace_id_lock = PTHREAD_MUTEX_INITIALIZER;
d3e2ba59 33
7591bab1 34static void rcu_destroy_ctf_trace(struct rcu_head *rcu_head)
2a174661 35{
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36 struct ctf_trace *trace =
37 caa_container_of(rcu_head, struct ctf_trace, rcu_node);
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38
39 free(trace);
40}
41
d3e2ba59 42/*
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43 * Destroy a ctf trace and all stream contained in it.
44 *
45 * MUST be called with the RCU read side lock.
d3e2ba59 46 */
7591bab1 47void ctf_trace_destroy(struct ctf_trace *trace)
d3e2ba59 48{
2a174661 49 /*
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50 * Getting to this point, every stream referenced by that trace
51 * have put back their ref since the've been closed by the
52 * control side.
2a174661 53 */
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54 assert(cds_list_empty(&trace->stream_list));
55 session_put(trace->session);
56 trace->session = NULL;
57 call_rcu(&trace->rcu_node, rcu_destroy_ctf_trace);
58}
2a174661 59
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60void ctf_trace_release(struct urcu_ref *ref)
61{
62 struct ctf_trace *trace =
63 caa_container_of(ref, struct ctf_trace, ref);
64 int ret;
65 struct lttng_ht_iter iter;
d3e2ba59 66
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67 iter.iter.node = &trace->node.node;
68 ret = lttng_ht_del(trace->session->ctf_traces_ht, &iter);
69 assert(!ret);
70 ctf_trace_destroy(trace);
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71}
72
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73/*
74 * Should be called with RCU read-side lock held.
75 */
76bool ctf_trace_get(struct ctf_trace *trace)
2a174661 77{
ce4d4083 78 return urcu_ref_get_unless_zero(&trace->ref);
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79}
80
81/*
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82 * Create and return an allocated ctf_trace. NULL on error.
83 * There is no "open" and "close" for a ctf_trace, but rather just a
84 * create and refcounting. Whenever all the streams belonging to a trace
85 * put their reference, its refcount drops to 0.
d3e2ba59 86 */
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87static struct ctf_trace *ctf_trace_create(struct relay_session *session,
88 char *path_name)
d3e2ba59 89{
7591bab1 90 struct ctf_trace *trace;
d3e2ba59 91
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92 trace = zmalloc(sizeof(*trace));
93 if (!trace) {
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94 PERROR("ctf_trace alloc");
95 goto error;
96 }
97
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98 if (!session_get(session)) {
99 ERR("Cannot get session");
100 free(trace);
101 trace = NULL;
102 goto error;
103 }
104 trace->session = session;
105
106 CDS_INIT_LIST_HEAD(&trace->stream_list);
107
108 pthread_mutex_lock(&last_relay_ctf_trace_id_lock);
109 trace->id = ++last_relay_ctf_trace_id;
110 pthread_mutex_unlock(&last_relay_ctf_trace_id_lock);
2a174661 111
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112 lttng_ht_node_init_str(&trace->node, path_name);
113 trace->session = session;
114 urcu_ref_init(&trace->ref);
115 pthread_mutex_init(&trace->lock, NULL);
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116 pthread_mutex_init(&trace->stream_list_lock, NULL);
117 lttng_ht_add_str(session->ctf_traces_ht, &trace->node);
2a174661 118
7591bab1 119 DBG("Created ctf_trace %" PRIu64 " with path: %s", trace->id, path_name);
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120
121error:
7591bab1 122 return trace;
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123}
124
125/*
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126 * Return a ctf_trace if found by id in the given hash table else NULL.
127 * Hold a reference on the ctf_trace, and must be paired with
128 * ctf_trace_put().
d3e2ba59 129 */
7591bab1 130struct ctf_trace *ctf_trace_get_by_path_or_create(struct relay_session *session,
2a174661 131 char *path_name)
d3e2ba59 132{
2a174661 133 struct lttng_ht_node_str *node;
d3e2ba59 134 struct lttng_ht_iter iter;
2a174661 135 struct ctf_trace *trace = NULL;
d3e2ba59 136
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137 rcu_read_lock();
138 lttng_ht_lookup(session->ctf_traces_ht, (void *) path_name, &iter);
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139 node = lttng_ht_iter_get_node_str(&iter);
140 if (!node) {
141 DBG("CTF Trace path %s not found", path_name);
142 goto end;
d3e2ba59 143 }
2a174661 144 trace = caa_container_of(node, struct ctf_trace, node);
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145 if (!ctf_trace_get(trace)) {
146 trace = NULL;
147 }
d3e2ba59 148end:
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149 rcu_read_unlock();
150 if (!trace) {
151 /* Try to create */
152 trace = ctf_trace_create(session, path_name);
153 }
2a174661 154 return trace;
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155}
156
7591bab1 157void ctf_trace_put(struct ctf_trace *trace)
2a174661 158{
7591bab1 159 rcu_read_lock();
7591bab1 160 urcu_ref_put(&trace->ref, ctf_trace_release);
7591bab1 161 rcu_read_unlock();
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162}
163
7591bab1 164int ctf_trace_close(struct ctf_trace *trace)
2a174661 165{
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166 struct relay_stream *stream;
167
168 rcu_read_lock();
169 cds_list_for_each_entry_rcu(stream, &trace->stream_list,
170 stream_node) {
171 /*
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172 * Close stream since the connection owning the trace is being
173 * torn down.
7591bab1 174 */
bda7c7b9 175 try_stream_close(stream);
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176 }
177 rcu_read_unlock();
178 /*
179 * Since all references to the trace are held by its streams, we
180 * don't need to do any self-ref put.
181 */
182 return 0;
183}
2a174661 184
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185struct relay_viewer_stream *ctf_trace_get_viewer_metadata_stream(struct ctf_trace *trace)
186{
187 struct relay_viewer_stream *vstream;
2a174661 188
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189 rcu_read_lock();
190 vstream = rcu_dereference(trace->viewer_metadata_stream);
191 if (!vstream) {
192 goto end;
193 }
194 if (!viewer_stream_get(vstream)) {
195 vstream = NULL;
196 }
197end:
198 rcu_read_unlock();
199 return vstream;
2a174661 200}
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