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 | 16 | #include <common/common.hpp> |
56047f5a | 17 | #include <common/urcu.hpp> |
28ab034a JG |
18 | #include <common/utils.hpp> |
19 | ||
20 | #include <urcu/rculist.h> | |
21 | ||
d3e2ba59 | 22 | static uint64_t last_relay_ctf_trace_id; |
7591bab1 | 23 | static pthread_mutex_t last_relay_ctf_trace_id_lock = PTHREAD_MUTEX_INITIALIZER; |
d3e2ba59 | 24 | |
7591bab1 | 25 | static void rcu_destroy_ctf_trace(struct rcu_head *rcu_head) |
2a174661 | 26 | { |
28ab034a | 27 | struct ctf_trace *trace = lttng::utils::container_of(rcu_head, &ctf_trace::rcu_node); |
2a174661 DG |
28 | |
29 | free(trace); | |
30 | } | |
31 | ||
d3e2ba59 | 32 | /* |
2a174661 DG |
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 | 37 | static void ctf_trace_destroy(struct ctf_trace *trace) |
d3e2ba59 | 38 | { |
2a174661 | 39 | /* |
7591bab1 MD |
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 | */ |
a0377dfe | 44 | LTTNG_ASSERT(cds_list_empty(&trace->stream_list)); |
48b7cdc2 FD |
45 | ASSERT_RCU_READ_LOCKED(); |
46 | ||
7591bab1 | 47 | session_put(trace->session); |
cd9adb8b | 48 | trace->session = nullptr; |
348a81dc | 49 | free(trace->path); |
cd9adb8b | 50 | trace->path = nullptr; |
7591bab1 MD |
51 | call_rcu(&trace->rcu_node, rcu_destroy_ctf_trace); |
52 | } | |
2a174661 | 53 | |
a1075e32 | 54 | static void ctf_trace_release(struct urcu_ref *ref) |
7591bab1 | 55 | { |
28ab034a | 56 | struct ctf_trace *trace = lttng::utils::container_of(ref, &ctf_trace::ref); |
7591bab1 MD |
57 | int ret; |
58 | struct lttng_ht_iter iter; | |
d3e2ba59 | 59 | |
7591bab1 MD |
60 | iter.iter.node = &trace->node.node; |
61 | ret = lttng_ht_del(trace->session->ctf_traces_ht, &iter); | |
a0377dfe | 62 | LTTNG_ASSERT(!ret); |
7591bab1 | 63 | ctf_trace_destroy(trace); |
2a174661 DG |
64 | } |
65 | ||
7591bab1 | 66 | /* |
48b7cdc2 FD |
67 | * The caller must either: |
68 | * - hold the RCU read side lock, or | |
69 | * - guarantee the existence of the object by already holding a reference to | |
70 | * the object. | |
7591bab1 MD |
71 | */ |
72 | bool ctf_trace_get(struct ctf_trace *trace) | |
2a174661 | 73 | { |
48b7cdc2 FD |
74 | const bool ref = urcu_ref_get_unless_zero(&trace->ref); |
75 | ||
76 | if (!ref) { | |
77 | /* | |
78 | * The ref count is already zero. It means the object is being | |
79 | * torn down concurently. | |
80 | * This is only acceptable if we hold the RCU read-side lock, | |
81 | * else it's a logic error. | |
82 | */ | |
83 | ASSERT_RCU_READ_LOCKED(); | |
84 | } | |
85 | ||
86 | return ref; | |
d3e2ba59 JD |
87 | } |
88 | ||
89 | /* | |
7591bab1 MD |
90 | * Create and return an allocated ctf_trace. NULL on error. |
91 | * There is no "open" and "close" for a ctf_trace, but rather just a | |
92 | * create and refcounting. Whenever all the streams belonging to a trace | |
93 | * put their reference, its refcount drops to 0. | |
d3e2ba59 | 94 | */ |
28ab034a | 95 | static struct ctf_trace *ctf_trace_create(struct relay_session *session, const char *subpath) |
d3e2ba59 | 96 | { |
7591bab1 | 97 | struct ctf_trace *trace; |
d3e2ba59 | 98 | |
64803277 | 99 | trace = zmalloc<ctf_trace>(); |
7591bab1 | 100 | if (!trace) { |
348a81dc JG |
101 | PERROR("Failed to allocate ctf_trace"); |
102 | goto end; | |
d3e2ba59 | 103 | } |
348a81dc | 104 | urcu_ref_init(&trace->ref); |
d3e2ba59 | 105 | |
7591bab1 | 106 | if (!session_get(session)) { |
348a81dc | 107 | ERR("Failed to acquire session reference"); |
7591bab1 MD |
108 | goto error; |
109 | } | |
110 | trace->session = session; | |
348a81dc JG |
111 | trace->path = strdup(subpath); |
112 | if (!trace->path) { | |
113 | goto error; | |
114 | } | |
7591bab1 MD |
115 | |
116 | CDS_INIT_LIST_HEAD(&trace->stream_list); | |
117 | ||
118 | pthread_mutex_lock(&last_relay_ctf_trace_id_lock); | |
119 | trace->id = ++last_relay_ctf_trace_id; | |
120 | pthread_mutex_unlock(&last_relay_ctf_trace_id_lock); | |
2a174661 | 121 | |
348a81dc | 122 | lttng_ht_node_init_str(&trace->node, trace->path); |
7591bab1 | 123 | trace->session = session; |
cd9adb8b JG |
124 | pthread_mutex_init(&trace->lock, nullptr); |
125 | pthread_mutex_init(&trace->stream_list_lock, nullptr); | |
7591bab1 | 126 | lttng_ht_add_str(session->ctf_traces_ht, &trace->node); |
2a174661 | 127 | |
9e0e2ff9 | 128 | DBG("Created ctf_trace %" PRIu64 " of session \"%s\" from host \"%s\" with path: %s", |
28ab034a JG |
129 | trace->id, |
130 | session->session_name, | |
131 | session->hostname, | |
132 | subpath); | |
d3e2ba59 | 133 | |
348a81dc | 134 | end: |
7591bab1 | 135 | return trace; |
348a81dc JG |
136 | error: |
137 | ctf_trace_put(trace); | |
cd9adb8b | 138 | return nullptr; |
d3e2ba59 JD |
139 | } |
140 | ||
141 | /* | |
7591bab1 MD |
142 | * Return a ctf_trace if found by id in the given hash table else NULL. |
143 | * Hold a reference on the ctf_trace, and must be paired with | |
144 | * ctf_trace_put(). | |
d3e2ba59 | 145 | */ |
7591bab1 | 146 | struct ctf_trace *ctf_trace_get_by_path_or_create(struct relay_session *session, |
28ab034a | 147 | const char *subpath) |
d3e2ba59 | 148 | { |
2a174661 | 149 | struct lttng_ht_node_str *node; |
d3e2ba59 | 150 | struct lttng_ht_iter iter; |
cd9adb8b | 151 | struct ctf_trace *trace = nullptr; |
d3e2ba59 | 152 | |
56047f5a | 153 | lttng::urcu::read_lock_guard read_lock; |
348a81dc | 154 | lttng_ht_lookup(session->ctf_traces_ht, subpath, &iter); |
2a174661 DG |
155 | node = lttng_ht_iter_get_node_str(&iter); |
156 | if (!node) { | |
348a81dc | 157 | DBG("CTF Trace path %s not found", subpath); |
2a174661 | 158 | goto end; |
d3e2ba59 | 159 | } |
0114db0e | 160 | trace = lttng::utils::container_of(node, &ctf_trace::node); |
7591bab1 | 161 | if (!ctf_trace_get(trace)) { |
cd9adb8b | 162 | trace = nullptr; |
7591bab1 | 163 | } |
d3e2ba59 | 164 | end: |
7591bab1 MD |
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 | { |
56047f5a | 174 | lttng::urcu::read_lock_guard read_lock; |
7591bab1 | 175 | urcu_ref_put(&trace->ref, ctf_trace_release); |
2a174661 DG |
176 | } |
177 | ||
7591bab1 | 178 | int ctf_trace_close(struct ctf_trace *trace) |
2a174661 | 179 | { |
7591bab1 MD |
180 | struct relay_stream *stream; |
181 | ||
56047f5a | 182 | lttng::urcu::read_lock_guard read_lock; |
28ab034a JG |
183 | cds_list_for_each_entry_rcu(stream, &trace->stream_list, stream_node) |
184 | { | |
7591bab1 | 185 | /* |
bda7c7b9 JG |
186 | * Close stream since the connection owning the trace is being |
187 | * torn down. | |
7591bab1 | 188 | */ |
bda7c7b9 | 189 | try_stream_close(stream); |
7591bab1 | 190 | } |
7591bab1 MD |
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 | |
56047f5a | 202 | lttng::urcu::read_lock_guard read_lock; |
7591bab1 MD |
203 | vstream = rcu_dereference(trace->viewer_metadata_stream); |
204 | if (!vstream) { | |
205 | goto end; | |
206 | } | |
207 | if (!viewer_stream_get(vstream)) { | |
cd9adb8b | 208 | vstream = nullptr; |
7591bab1 MD |
209 | } |
210 | end: | |
7591bab1 | 211 | return vstream; |
2a174661 | 212 | } |