Commit | Line | Data |
---|---|---|
d3e2ba59 | 1 | /* |
ab5be9fa MJ |
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 | * |
d3e2ba59 JD |
8 | */ |
9 | ||
6c1c0768 | 10 | #define _LGPL_SOURCE |
d3e2ba59 | 11 | |
c9e313bc SM |
12 | #include "ctf-trace.hpp" |
13 | #include "lttng-relayd.hpp" | |
14 | #include "stream.hpp" | |
d3e2ba59 | 15 | |
28ab034a JG |
16 | #include <common/common.hpp> |
17 | #include <common/utils.hpp> | |
18 | ||
19 | #include <urcu/rculist.h> | |
20 | ||
d3e2ba59 | 21 | static uint64_t last_relay_ctf_trace_id; |
7591bab1 | 22 | static pthread_mutex_t last_relay_ctf_trace_id_lock = PTHREAD_MUTEX_INITIALIZER; |
d3e2ba59 | 23 | |
7591bab1 | 24 | static void rcu_destroy_ctf_trace(struct rcu_head *rcu_head) |
2a174661 | 25 | { |
28ab034a | 26 | struct ctf_trace *trace = lttng::utils::container_of(rcu_head, &ctf_trace::rcu_node); |
2a174661 DG |
27 | |
28 | free(trace); | |
29 | } | |
30 | ||
d3e2ba59 | 31 | /* |
2a174661 DG |
32 | * Destroy a ctf trace and all stream contained in it. |
33 | * | |
34 | * MUST be called with the RCU read side lock. | |
d3e2ba59 | 35 | */ |
a1075e32 | 36 | static void ctf_trace_destroy(struct ctf_trace *trace) |
d3e2ba59 | 37 | { |
2a174661 | 38 | /* |
7591bab1 MD |
39 | * Getting to this point, every stream referenced by that trace |
40 | * have put back their ref since the've been closed by the | |
41 | * control side. | |
2a174661 | 42 | */ |
a0377dfe | 43 | LTTNG_ASSERT(cds_list_empty(&trace->stream_list)); |
48b7cdc2 FD |
44 | ASSERT_RCU_READ_LOCKED(); |
45 | ||
7591bab1 | 46 | session_put(trace->session); |
cd9adb8b | 47 | trace->session = nullptr; |
348a81dc | 48 | free(trace->path); |
cd9adb8b | 49 | trace->path = nullptr; |
7591bab1 MD |
50 | call_rcu(&trace->rcu_node, rcu_destroy_ctf_trace); |
51 | } | |
2a174661 | 52 | |
a1075e32 | 53 | static void ctf_trace_release(struct urcu_ref *ref) |
7591bab1 | 54 | { |
28ab034a | 55 | struct ctf_trace *trace = lttng::utils::container_of(ref, &ctf_trace::ref); |
7591bab1 MD |
56 | int ret; |
57 | struct lttng_ht_iter iter; | |
d3e2ba59 | 58 | |
7591bab1 MD |
59 | iter.iter.node = &trace->node.node; |
60 | ret = lttng_ht_del(trace->session->ctf_traces_ht, &iter); | |
a0377dfe | 61 | LTTNG_ASSERT(!ret); |
7591bab1 | 62 | ctf_trace_destroy(trace); |
2a174661 DG |
63 | } |
64 | ||
7591bab1 | 65 | /* |
48b7cdc2 FD |
66 | * The caller must either: |
67 | * - hold the RCU read side lock, or | |
68 | * - guarantee the existence of the object by already holding a reference to | |
69 | * the object. | |
7591bab1 MD |
70 | */ |
71 | bool ctf_trace_get(struct ctf_trace *trace) | |
2a174661 | 72 | { |
48b7cdc2 FD |
73 | const bool ref = urcu_ref_get_unless_zero(&trace->ref); |
74 | ||
75 | if (!ref) { | |
76 | /* | |
77 | * The ref count is already zero. It means the object is being | |
78 | * torn down concurently. | |
79 | * This is only acceptable if we hold the RCU read-side lock, | |
80 | * else it's a logic error. | |
81 | */ | |
82 | ASSERT_RCU_READ_LOCKED(); | |
83 | } | |
84 | ||
85 | return ref; | |
d3e2ba59 JD |
86 | } |
87 | ||
88 | /* | |
7591bab1 MD |
89 | * Create and return an allocated ctf_trace. NULL on error. |
90 | * There is no "open" and "close" for a ctf_trace, but rather just a | |
91 | * create and refcounting. Whenever all the streams belonging to a trace | |
92 | * put their reference, its refcount drops to 0. | |
d3e2ba59 | 93 | */ |
28ab034a | 94 | static struct ctf_trace *ctf_trace_create(struct relay_session *session, const char *subpath) |
d3e2ba59 | 95 | { |
7591bab1 | 96 | struct ctf_trace *trace; |
d3e2ba59 | 97 | |
64803277 | 98 | trace = zmalloc<ctf_trace>(); |
7591bab1 | 99 | if (!trace) { |
348a81dc JG |
100 | PERROR("Failed to allocate ctf_trace"); |
101 | goto end; | |
d3e2ba59 | 102 | } |
348a81dc | 103 | urcu_ref_init(&trace->ref); |
d3e2ba59 | 104 | |
7591bab1 | 105 | if (!session_get(session)) { |
348a81dc | 106 | ERR("Failed to acquire session reference"); |
7591bab1 MD |
107 | goto error; |
108 | } | |
109 | trace->session = session; | |
348a81dc JG |
110 | trace->path = strdup(subpath); |
111 | if (!trace->path) { | |
112 | goto error; | |
113 | } | |
7591bab1 MD |
114 | |
115 | CDS_INIT_LIST_HEAD(&trace->stream_list); | |
116 | ||
117 | pthread_mutex_lock(&last_relay_ctf_trace_id_lock); | |
118 | trace->id = ++last_relay_ctf_trace_id; | |
119 | pthread_mutex_unlock(&last_relay_ctf_trace_id_lock); | |
2a174661 | 120 | |
348a81dc | 121 | lttng_ht_node_init_str(&trace->node, trace->path); |
7591bab1 | 122 | trace->session = session; |
cd9adb8b JG |
123 | pthread_mutex_init(&trace->lock, nullptr); |
124 | pthread_mutex_init(&trace->stream_list_lock, nullptr); | |
7591bab1 | 125 | lttng_ht_add_str(session->ctf_traces_ht, &trace->node); |
2a174661 | 126 | |
9e0e2ff9 | 127 | DBG("Created ctf_trace %" PRIu64 " of session \"%s\" from host \"%s\" with path: %s", |
28ab034a JG |
128 | trace->id, |
129 | session->session_name, | |
130 | session->hostname, | |
131 | subpath); | |
d3e2ba59 | 132 | |
348a81dc | 133 | end: |
7591bab1 | 134 | return trace; |
348a81dc JG |
135 | error: |
136 | ctf_trace_put(trace); | |
cd9adb8b | 137 | return nullptr; |
d3e2ba59 JD |
138 | } |
139 | ||
140 | /* | |
7591bab1 MD |
141 | * Return a ctf_trace if found by id in the given hash table else NULL. |
142 | * Hold a reference on the ctf_trace, and must be paired with | |
143 | * ctf_trace_put(). | |
d3e2ba59 | 144 | */ |
7591bab1 | 145 | struct ctf_trace *ctf_trace_get_by_path_or_create(struct relay_session *session, |
28ab034a | 146 | const char *subpath) |
d3e2ba59 | 147 | { |
2a174661 | 148 | struct lttng_ht_node_str *node; |
d3e2ba59 | 149 | struct lttng_ht_iter iter; |
cd9adb8b | 150 | struct ctf_trace *trace = nullptr; |
d3e2ba59 | 151 | |
7591bab1 | 152 | rcu_read_lock(); |
348a81dc | 153 | lttng_ht_lookup(session->ctf_traces_ht, subpath, &iter); |
2a174661 DG |
154 | node = lttng_ht_iter_get_node_str(&iter); |
155 | if (!node) { | |
348a81dc | 156 | DBG("CTF Trace path %s not found", subpath); |
2a174661 | 157 | goto end; |
d3e2ba59 | 158 | } |
0114db0e | 159 | trace = lttng::utils::container_of(node, &ctf_trace::node); |
7591bab1 | 160 | if (!ctf_trace_get(trace)) { |
cd9adb8b | 161 | trace = nullptr; |
7591bab1 | 162 | } |
d3e2ba59 | 163 | end: |
7591bab1 MD |
164 | rcu_read_unlock(); |
165 | if (!trace) { | |
166 | /* Try to create */ | |
348a81dc | 167 | trace = ctf_trace_create(session, subpath); |
7591bab1 | 168 | } |
2a174661 | 169 | return trace; |
d3e2ba59 JD |
170 | } |
171 | ||
7591bab1 | 172 | void ctf_trace_put(struct ctf_trace *trace) |
2a174661 | 173 | { |
7591bab1 | 174 | rcu_read_lock(); |
7591bab1 | 175 | urcu_ref_put(&trace->ref, ctf_trace_release); |
7591bab1 | 176 | rcu_read_unlock(); |
2a174661 DG |
177 | } |
178 | ||
7591bab1 | 179 | int ctf_trace_close(struct ctf_trace *trace) |
2a174661 | 180 | { |
7591bab1 MD |
181 | struct relay_stream *stream; |
182 | ||
183 | rcu_read_lock(); | |
28ab034a JG |
184 | cds_list_for_each_entry_rcu(stream, &trace->stream_list, stream_node) |
185 | { | |
7591bab1 | 186 | /* |
bda7c7b9 JG |
187 | * Close stream since the connection owning the trace is being |
188 | * torn down. | |
7591bab1 | 189 | */ |
bda7c7b9 | 190 | try_stream_close(stream); |
7591bab1 MD |
191 | } |
192 | rcu_read_unlock(); | |
193 | /* | |
194 | * Since all references to the trace are held by its streams, we | |
195 | * don't need to do any self-ref put. | |
196 | */ | |
197 | return 0; | |
198 | } | |
2a174661 | 199 | |
7591bab1 MD |
200 | struct relay_viewer_stream *ctf_trace_get_viewer_metadata_stream(struct ctf_trace *trace) |
201 | { | |
202 | struct relay_viewer_stream *vstream; | |
2a174661 | 203 | |
7591bab1 MD |
204 | rcu_read_lock(); |
205 | vstream = rcu_dereference(trace->viewer_metadata_stream); | |
206 | if (!vstream) { | |
207 | goto end; | |
208 | } | |
209 | if (!viewer_stream_get(vstream)) { | |
cd9adb8b | 210 | vstream = nullptr; |
7591bab1 MD |
211 | } |
212 | end: | |
213 | rcu_read_unlock(); | |
214 | return vstream; | |
2a174661 | 215 | } |