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