| 1 | /* |
| 2 | * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca> |
| 3 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 4 | * Copyright (C) 2013 - David Goulet <dgoulet@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 _GNU_SOURCE |
| 21 | #include <assert.h> |
| 22 | #include <inttypes.h> |
| 23 | #include <sys/mman.h> |
| 24 | #include <unistd.h> |
| 25 | |
| 26 | #include <common/common.h> |
| 27 | #include <common/relayd/relayd.h> |
| 28 | #include <common/ust-consumer/ust-consumer.h> |
| 29 | |
| 30 | #include "consumer-stream.h" |
| 31 | |
| 32 | /* |
| 33 | * RCU call to free stream. MUST only be used with call_rcu(). |
| 34 | */ |
| 35 | static void free_stream_rcu(struct rcu_head *head) |
| 36 | { |
| 37 | struct lttng_ht_node_u64 *node = |
| 38 | caa_container_of(head, struct lttng_ht_node_u64, head); |
| 39 | struct lttng_consumer_stream *stream = |
| 40 | caa_container_of(node, struct lttng_consumer_stream, node); |
| 41 | |
| 42 | pthread_mutex_destroy(&stream->lock); |
| 43 | free(stream); |
| 44 | } |
| 45 | |
| 46 | /* |
| 47 | * Close stream on the relayd side. This call can destroy a relayd if the |
| 48 | * conditions are met. |
| 49 | * |
| 50 | * A RCU read side lock MUST be acquired if the relayd object was looked up in |
| 51 | * a hash table before calling this. |
| 52 | */ |
| 53 | void consumer_stream_relayd_close(struct lttng_consumer_stream *stream, |
| 54 | struct consumer_relayd_sock_pair *relayd) |
| 55 | { |
| 56 | int ret; |
| 57 | |
| 58 | assert(stream); |
| 59 | assert(relayd); |
| 60 | |
| 61 | if (stream->sent_to_relayd) { |
| 62 | uatomic_dec(&relayd->refcount); |
| 63 | assert(uatomic_read(&relayd->refcount) >= 0); |
| 64 | } |
| 65 | |
| 66 | /* Closing streams requires to lock the control socket. */ |
| 67 | pthread_mutex_lock(&relayd->ctrl_sock_mutex); |
| 68 | ret = relayd_send_close_stream(&relayd->control_sock, |
| 69 | stream->relayd_stream_id, |
| 70 | stream->next_net_seq_num - 1); |
| 71 | pthread_mutex_unlock(&relayd->ctrl_sock_mutex); |
| 72 | if (ret < 0) { |
| 73 | DBG("Unable to close stream on the relayd. Continuing"); |
| 74 | /* |
| 75 | * Continue here. There is nothing we can do for the relayd. |
| 76 | * Chances are that the relayd has closed the socket so we just |
| 77 | * continue cleaning up. |
| 78 | */ |
| 79 | } |
| 80 | |
| 81 | /* Both conditions are met, we destroy the relayd. */ |
| 82 | if (uatomic_read(&relayd->refcount) == 0 && |
| 83 | uatomic_read(&relayd->destroy_flag)) { |
| 84 | consumer_destroy_relayd(relayd); |
| 85 | } |
| 86 | stream->net_seq_idx = (uint64_t) -1ULL; |
| 87 | stream->sent_to_relayd = 0; |
| 88 | } |
| 89 | |
| 90 | /* |
| 91 | * Close stream's file descriptors and, if needed, close stream also on the |
| 92 | * relayd side. |
| 93 | * |
| 94 | * The consumer data lock MUST be acquired. |
| 95 | * The stream lock MUST be acquired. |
| 96 | */ |
| 97 | void consumer_stream_close(struct lttng_consumer_stream *stream) |
| 98 | { |
| 99 | int ret; |
| 100 | struct consumer_relayd_sock_pair *relayd; |
| 101 | |
| 102 | assert(stream); |
| 103 | |
| 104 | switch (consumer_data.type) { |
| 105 | case LTTNG_CONSUMER_KERNEL: |
| 106 | if (stream->mmap_base != NULL) { |
| 107 | ret = munmap(stream->mmap_base, stream->mmap_len); |
| 108 | if (ret != 0) { |
| 109 | PERROR("munmap"); |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | if (stream->wait_fd >= 0) { |
| 114 | ret = close(stream->wait_fd); |
| 115 | if (ret) { |
| 116 | PERROR("close"); |
| 117 | } |
| 118 | stream->wait_fd = -1; |
| 119 | } |
| 120 | break; |
| 121 | case LTTNG_CONSUMER32_UST: |
| 122 | case LTTNG_CONSUMER64_UST: |
| 123 | break; |
| 124 | default: |
| 125 | ERR("Unknown consumer_data type"); |
| 126 | assert(0); |
| 127 | } |
| 128 | |
| 129 | /* Close output fd. Could be a socket or local file at this point. */ |
| 130 | if (stream->out_fd >= 0) { |
| 131 | ret = close(stream->out_fd); |
| 132 | if (ret) { |
| 133 | PERROR("close"); |
| 134 | } |
| 135 | stream->out_fd = -1; |
| 136 | } |
| 137 | |
| 138 | /* Check and cleanup relayd if needed. */ |
| 139 | rcu_read_lock(); |
| 140 | relayd = consumer_find_relayd(stream->net_seq_idx); |
| 141 | if (relayd != NULL) { |
| 142 | consumer_stream_relayd_close(stream, relayd); |
| 143 | } |
| 144 | rcu_read_unlock(); |
| 145 | } |
| 146 | |
| 147 | /* |
| 148 | * Delete the stream from all possible hash tables. |
| 149 | * |
| 150 | * The consumer data lock MUST be acquired. |
| 151 | * The stream lock MUST be acquired. |
| 152 | */ |
| 153 | void consumer_stream_delete(struct lttng_consumer_stream *stream, |
| 154 | struct lttng_ht *ht) |
| 155 | { |
| 156 | int ret; |
| 157 | struct lttng_ht_iter iter; |
| 158 | |
| 159 | assert(stream); |
| 160 | /* Should NEVER be called not in monitor mode. */ |
| 161 | assert(stream->chan->monitor); |
| 162 | |
| 163 | rcu_read_lock(); |
| 164 | |
| 165 | if (ht) { |
| 166 | iter.iter.node = &stream->node.node; |
| 167 | ret = lttng_ht_del(ht, &iter); |
| 168 | assert(!ret); |
| 169 | } |
| 170 | |
| 171 | /* Delete from stream per channel ID hash table. */ |
| 172 | iter.iter.node = &stream->node_channel_id.node; |
| 173 | /* |
| 174 | * The returned value is of no importance. Even if the node is NOT in the |
| 175 | * hash table, we continue since we may have been called by a code path |
| 176 | * that did not add the stream to a (all) hash table. Same goes for the |
| 177 | * next call ht del call. |
| 178 | */ |
| 179 | (void) lttng_ht_del(consumer_data.stream_per_chan_id_ht, &iter); |
| 180 | |
| 181 | /* Delete from the global stream list. */ |
| 182 | iter.iter.node = &stream->node_session_id.node; |
| 183 | /* See the previous ht del on why we ignore the returned value. */ |
| 184 | (void) lttng_ht_del(consumer_data.stream_list_ht, &iter); |
| 185 | |
| 186 | rcu_read_unlock(); |
| 187 | |
| 188 | /* Decrement the stream count of the global consumer data. */ |
| 189 | assert(consumer_data.stream_count > 0); |
| 190 | consumer_data.stream_count--; |
| 191 | } |
| 192 | |
| 193 | /* |
| 194 | * Free the given stream within a RCU call. |
| 195 | */ |
| 196 | void consumer_stream_free(struct lttng_consumer_stream *stream) |
| 197 | { |
| 198 | assert(stream); |
| 199 | |
| 200 | call_rcu(&stream->node.head, free_stream_rcu); |
| 201 | } |
| 202 | |
| 203 | /* |
| 204 | * Destroy the stream's buffers of the tracer. |
| 205 | */ |
| 206 | void consumer_stream_destroy_buffers(struct lttng_consumer_stream *stream) |
| 207 | { |
| 208 | assert(stream); |
| 209 | |
| 210 | switch (consumer_data.type) { |
| 211 | case LTTNG_CONSUMER_KERNEL: |
| 212 | break; |
| 213 | case LTTNG_CONSUMER32_UST: |
| 214 | case LTTNG_CONSUMER64_UST: |
| 215 | lttng_ustconsumer_del_stream(stream); |
| 216 | break; |
| 217 | default: |
| 218 | ERR("Unknown consumer_data type"); |
| 219 | assert(0); |
| 220 | } |
| 221 | } |
| 222 | |
| 223 | /* |
| 224 | * Destroy and close a already created stream. |
| 225 | */ |
| 226 | static void destroy_close_stream(struct lttng_consumer_stream *stream) |
| 227 | { |
| 228 | assert(stream); |
| 229 | |
| 230 | DBG("Consumer stream destroy monitored key: %" PRIu64, stream->key); |
| 231 | |
| 232 | /* Destroy tracer buffers of the stream. */ |
| 233 | consumer_stream_destroy_buffers(stream); |
| 234 | /* Close down everything including the relayd if one. */ |
| 235 | consumer_stream_close(stream); |
| 236 | } |
| 237 | |
| 238 | /* |
| 239 | * Decrement the stream's channel refcount and if down to 0, return the channel |
| 240 | * pointer so it can be destroyed by the caller or NULL if not. |
| 241 | */ |
| 242 | static struct lttng_consumer_channel *unref_channel( |
| 243 | struct lttng_consumer_stream *stream) |
| 244 | { |
| 245 | struct lttng_consumer_channel *free_chan = NULL; |
| 246 | |
| 247 | assert(stream); |
| 248 | assert(stream->chan); |
| 249 | |
| 250 | /* Update refcount of channel and see if we need to destroy it. */ |
| 251 | if (!uatomic_sub_return(&stream->chan->refcount, 1) |
| 252 | && !uatomic_read(&stream->chan->nb_init_stream_left)) { |
| 253 | free_chan = stream->chan; |
| 254 | } |
| 255 | |
| 256 | return free_chan; |
| 257 | } |
| 258 | |
| 259 | /* |
| 260 | * Destroy a stream completely. This will delete, close and free the stream. |
| 261 | * Once return, the stream is NO longer usable. Its channel may get destroyed |
| 262 | * if conditions are met for a monitored stream. |
| 263 | * |
| 264 | * This MUST be called WITHOUT the consumer data and stream lock acquired if |
| 265 | * the stream is in _monitor_ mode else it does not matter. |
| 266 | */ |
| 267 | void consumer_stream_destroy(struct lttng_consumer_stream *stream, |
| 268 | struct lttng_ht *ht) |
| 269 | { |
| 270 | assert(stream); |
| 271 | |
| 272 | /* Stream is in monitor mode. */ |
| 273 | if (stream->monitor) { |
| 274 | struct lttng_consumer_channel *free_chan = NULL; |
| 275 | |
| 276 | /* |
| 277 | * This means that the stream was successfully removed from the streams |
| 278 | * list of the channel and sent to the right thread managing this |
| 279 | * stream thus being globally visible. |
| 280 | */ |
| 281 | if (stream->globally_visible) { |
| 282 | pthread_mutex_lock(&consumer_data.lock); |
| 283 | pthread_mutex_lock(&stream->chan->lock); |
| 284 | pthread_mutex_lock(&stream->chan->timer_lock); |
| 285 | pthread_mutex_lock(&stream->lock); |
| 286 | /* Remove every reference of the stream in the consumer. */ |
| 287 | consumer_stream_delete(stream, ht); |
| 288 | |
| 289 | destroy_close_stream(stream); |
| 290 | |
| 291 | /* Update channel's refcount of the stream. */ |
| 292 | free_chan = unref_channel(stream); |
| 293 | |
| 294 | /* Indicates that the consumer data state MUST be updated after this. */ |
| 295 | consumer_data.need_update = 1; |
| 296 | |
| 297 | pthread_mutex_unlock(&stream->lock); |
| 298 | pthread_mutex_unlock(&stream->chan->timer_lock); |
| 299 | pthread_mutex_unlock(&stream->chan->lock); |
| 300 | pthread_mutex_unlock(&consumer_data.lock); |
| 301 | } else { |
| 302 | /* |
| 303 | * If the stream is not visible globally, this needs to be done |
| 304 | * outside of the consumer data lock section. |
| 305 | */ |
| 306 | free_chan = unref_channel(stream); |
| 307 | } |
| 308 | |
| 309 | if (free_chan) { |
| 310 | consumer_del_channel(free_chan); |
| 311 | } |
| 312 | } else { |
| 313 | destroy_close_stream(stream); |
| 314 | } |
| 315 | |
| 316 | /* Free stream within a RCU call. */ |
| 317 | consumer_stream_free(stream); |
| 318 | } |