notification-thread: remove fd from pollset on LPOLLHUP and friends
[lttng-tools.git] / src / bin / lttng-relayd / ctf-trace.c
CommitLineData
d3e2ba59 1/*
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2 * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
3 * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
4 * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
d3e2ba59 5 *
ab5be9fa 6 * SPDX-License-Identifier: GPL-2.0-only
d3e2ba59 7 *
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8 */
9
6c1c0768 10#define _LGPL_SOURCE
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11#include <assert.h>
12
13#include <common/common.h>
14#include <common/utils.h>
7591bab1 15#include <urcu/rculist.h>
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16
17#include "ctf-trace.h"
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18#include "lttng-relayd.h"
19#include "stream.h"
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20
21static uint64_t last_relay_ctf_trace_id;
7591bab1 22static pthread_mutex_t last_relay_ctf_trace_id_lock = PTHREAD_MUTEX_INITIALIZER;
d3e2ba59 23
7591bab1 24static void rcu_destroy_ctf_trace(struct rcu_head *rcu_head)
2a174661 25{
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26 struct ctf_trace *trace =
27 caa_container_of(rcu_head, struct ctf_trace, rcu_node);
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28
29 free(trace);
30}
31
d3e2ba59 32/*
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33 * Destroy a ctf trace and all stream contained in it.
34 *
35 * MUST be called with the RCU read side lock.
d3e2ba59 36 */
a1075e32 37static void ctf_trace_destroy(struct ctf_trace *trace)
d3e2ba59 38{
2a174661 39 /*
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40 * Getting to this point, every stream referenced by that trace
41 * have put back their ref since the've been closed by the
42 * control side.
2a174661 43 */
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MD
44 assert(cds_list_empty(&trace->stream_list));
45 session_put(trace->session);
46 trace->session = NULL;
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47 free(trace->path);
48 trace->path = NULL;
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49 call_rcu(&trace->rcu_node, rcu_destroy_ctf_trace);
50}
2a174661 51
a1075e32 52static void ctf_trace_release(struct urcu_ref *ref)
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53{
54 struct ctf_trace *trace =
55 caa_container_of(ref, struct ctf_trace, ref);
56 int ret;
57 struct lttng_ht_iter iter;
d3e2ba59 58
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59 iter.iter.node = &trace->node.node;
60 ret = lttng_ht_del(trace->session->ctf_traces_ht, &iter);
61 assert(!ret);
62 ctf_trace_destroy(trace);
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63}
64
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65/*
66 * Should be called with RCU read-side lock held.
67 */
68bool ctf_trace_get(struct ctf_trace *trace)
2a174661 69{
ce4d4083 70 return urcu_ref_get_unless_zero(&trace->ref);
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71}
72
73/*
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74 * Create and return an allocated ctf_trace. NULL on error.
75 * There is no "open" and "close" for a ctf_trace, but rather just a
76 * create and refcounting. Whenever all the streams belonging to a trace
77 * put their reference, its refcount drops to 0.
d3e2ba59 78 */
7591bab1 79static struct ctf_trace *ctf_trace_create(struct relay_session *session,
348a81dc 80 const char *subpath)
d3e2ba59 81{
7591bab1 82 struct ctf_trace *trace;
d3e2ba59 83
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84 trace = zmalloc(sizeof(*trace));
85 if (!trace) {
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86 PERROR("Failed to allocate ctf_trace");
87 goto end;
d3e2ba59 88 }
348a81dc 89 urcu_ref_init(&trace->ref);
d3e2ba59 90
7591bab1 91 if (!session_get(session)) {
348a81dc 92 ERR("Failed to acquire session reference");
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93 goto error;
94 }
95 trace->session = session;
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96 trace->path = strdup(subpath);
97 if (!trace->path) {
98 goto error;
99 }
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100
101 CDS_INIT_LIST_HEAD(&trace->stream_list);
102
103 pthread_mutex_lock(&last_relay_ctf_trace_id_lock);
104 trace->id = ++last_relay_ctf_trace_id;
105 pthread_mutex_unlock(&last_relay_ctf_trace_id_lock);
2a174661 106
348a81dc 107 lttng_ht_node_init_str(&trace->node, trace->path);
7591bab1 108 trace->session = session;
7591bab1 109 pthread_mutex_init(&trace->lock, NULL);
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110 pthread_mutex_init(&trace->stream_list_lock, NULL);
111 lttng_ht_add_str(session->ctf_traces_ht, &trace->node);
2a174661 112
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113 DBG("Created ctf_trace %" PRIu64 "of session \"%s\" from host \"%s\" with path: %s",
114 trace->id, session->session_name, session->hostname,
115 subpath);
d3e2ba59 116
348a81dc 117end:
7591bab1 118 return trace;
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119error:
120 ctf_trace_put(trace);
121 return NULL;
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122}
123
124/*
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125 * Return a ctf_trace if found by id in the given hash table else NULL.
126 * Hold a reference on the ctf_trace, and must be paired with
127 * ctf_trace_put().
d3e2ba59 128 */
7591bab1 129struct ctf_trace *ctf_trace_get_by_path_or_create(struct relay_session *session,
348a81dc 130 const char *subpath)
d3e2ba59 131{
2a174661 132 struct lttng_ht_node_str *node;
d3e2ba59 133 struct lttng_ht_iter iter;
2a174661 134 struct ctf_trace *trace = NULL;
d3e2ba59 135
7591bab1 136 rcu_read_lock();
348a81dc 137 lttng_ht_lookup(session->ctf_traces_ht, subpath, &iter);
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138 node = lttng_ht_iter_get_node_str(&iter);
139 if (!node) {
348a81dc 140 DBG("CTF Trace path %s not found", subpath);
2a174661 141 goto end;
d3e2ba59 142 }
2a174661 143 trace = caa_container_of(node, struct ctf_trace, node);
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144 if (!ctf_trace_get(trace)) {
145 trace = NULL;
146 }
d3e2ba59 147end:
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148 rcu_read_unlock();
149 if (!trace) {
150 /* Try to create */
348a81dc 151 trace = ctf_trace_create(session, subpath);
7591bab1 152 }
2a174661 153 return trace;
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154}
155
7591bab1 156void ctf_trace_put(struct ctf_trace *trace)
2a174661 157{
7591bab1 158 rcu_read_lock();
7591bab1 159 urcu_ref_put(&trace->ref, ctf_trace_release);
7591bab1 160 rcu_read_unlock();
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161}
162
7591bab1 163int ctf_trace_close(struct ctf_trace *trace)
2a174661 164{
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165 struct relay_stream *stream;
166
167 rcu_read_lock();
168 cds_list_for_each_entry_rcu(stream, &trace->stream_list,
169 stream_node) {
170 /*
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171 * Close stream since the connection owning the trace is being
172 * torn down.
7591bab1 173 */
bda7c7b9 174 try_stream_close(stream);
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175 }
176 rcu_read_unlock();
177 /*
178 * Since all references to the trace are held by its streams, we
179 * don't need to do any self-ref put.
180 */
181 return 0;
182}
2a174661 183
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184struct relay_viewer_stream *ctf_trace_get_viewer_metadata_stream(struct ctf_trace *trace)
185{
186 struct relay_viewer_stream *vstream;
2a174661 187
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188 rcu_read_lock();
189 vstream = rcu_dereference(trace->viewer_metadata_stream);
190 if (!vstream) {
191 goto end;
192 }
193 if (!viewer_stream_get(vstream)) {
194 vstream = NULL;
195 }
196end:
197 rcu_read_unlock();
198 return vstream;
2a174661 199}
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