| 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 <sys/mman.h> |
| 23 | #include <unistd.h> |
| 24 | |
| 25 | #include <common/common.h> |
| 26 | #include <common/relayd/relayd.h> |
| 27 | #include <common/ust-consumer/ust-consumer.h> |
| 28 | |
| 29 | #include "consumer-stream.h" |
| 30 | |
| 31 | /* |
| 32 | * RCU call to free stream. MUST only be used with call_rcu(). |
| 33 | */ |
| 34 | static void free_stream_rcu(struct rcu_head *head) |
| 35 | { |
| 36 | struct lttng_ht_node_u64 *node = |
| 37 | caa_container_of(head, struct lttng_ht_node_u64, head); |
| 38 | struct lttng_consumer_stream *stream = |
| 39 | caa_container_of(node, struct lttng_consumer_stream, node); |
| 40 | |
| 41 | pthread_mutex_destroy(&stream->lock); |
| 42 | free(stream); |
| 43 | } |
| 44 | |
| 45 | /* |
| 46 | * Close stream on the relayd side. This call can destroy a relayd if the |
| 47 | * conditions are met. |
| 48 | * |
| 49 | * A RCU read side lock MUST be acquired if the relayd object was looked up in |
| 50 | * a hash table before calling this. |
| 51 | */ |
| 52 | void consumer_stream_relayd_close(struct lttng_consumer_stream *stream, |
| 53 | struct consumer_relayd_sock_pair *relayd) |
| 54 | { |
| 55 | int ret; |
| 56 | |
| 57 | assert(stream); |
| 58 | assert(relayd); |
| 59 | |
| 60 | uatomic_dec(&relayd->refcount); |
| 61 | assert(uatomic_read(&relayd->refcount) >= 0); |
| 62 | |
| 63 | /* Closing streams requires to lock the control socket. */ |
| 64 | pthread_mutex_lock(&relayd->ctrl_sock_mutex); |
| 65 | ret = relayd_send_close_stream(&relayd->control_sock, |
| 66 | stream->relayd_stream_id, |
| 67 | stream->next_net_seq_num - 1); |
| 68 | pthread_mutex_unlock(&relayd->ctrl_sock_mutex); |
| 69 | if (ret < 0) { |
| 70 | DBG("Unable to close stream on the relayd. Continuing"); |
| 71 | /* |
| 72 | * Continue here. There is nothing we can do for the relayd. |
| 73 | * Chances are that the relayd has closed the socket so we just |
| 74 | * continue cleaning up. |
| 75 | */ |
| 76 | } |
| 77 | |
| 78 | /* Both conditions are met, we destroy the relayd. */ |
| 79 | if (uatomic_read(&relayd->refcount) == 0 && |
| 80 | uatomic_read(&relayd->destroy_flag)) { |
| 81 | consumer_destroy_relayd(relayd); |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | /* |
| 86 | * Close stream's file descriptors and, if needed, close stream also on the |
| 87 | * relayd side. |
| 88 | * |
| 89 | * The consumer data lock MUST be acquired. |
| 90 | * The stream lock MUST be acquired. |
| 91 | */ |
| 92 | void consumer_stream_close(struct lttng_consumer_stream *stream) |
| 93 | { |
| 94 | int ret; |
| 95 | struct consumer_relayd_sock_pair *relayd; |
| 96 | |
| 97 | assert(stream); |
| 98 | |
| 99 | switch (consumer_data.type) { |
| 100 | case LTTNG_CONSUMER_KERNEL: |
| 101 | if (stream->mmap_base != NULL) { |
| 102 | ret = munmap(stream->mmap_base, stream->mmap_len); |
| 103 | if (ret != 0) { |
| 104 | PERROR("munmap"); |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | if (stream->wait_fd >= 0) { |
| 109 | ret = close(stream->wait_fd); |
| 110 | if (ret) { |
| 111 | PERROR("close"); |
| 112 | } |
| 113 | } |
| 114 | break; |
| 115 | case LTTNG_CONSUMER32_UST: |
| 116 | case LTTNG_CONSUMER64_UST: |
| 117 | lttng_ustconsumer_del_stream(stream); |
| 118 | break; |
| 119 | default: |
| 120 | ERR("Unknown consumer_data type"); |
| 121 | assert(0); |
| 122 | } |
| 123 | |
| 124 | /* Close output fd. Could be a socket or local file at this point. */ |
| 125 | if (stream->out_fd >= 0) { |
| 126 | ret = close(stream->out_fd); |
| 127 | if (ret) { |
| 128 | PERROR("close"); |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | /* Check and cleanup relayd if needed. */ |
| 133 | rcu_read_lock(); |
| 134 | relayd = consumer_find_relayd(stream->net_seq_idx); |
| 135 | if (relayd != NULL) { |
| 136 | consumer_stream_relayd_close(stream, relayd); |
| 137 | } |
| 138 | rcu_read_unlock(); |
| 139 | } |
| 140 | |
| 141 | /* |
| 142 | * Delete the stream from all possible hash tables. |
| 143 | * |
| 144 | * The consumer data lock MUST be acquired. |
| 145 | * The stream lock MUST be acquired. |
| 146 | */ |
| 147 | void consumer_stream_delete(struct lttng_consumer_stream *stream, |
| 148 | struct lttng_ht *ht) |
| 149 | { |
| 150 | int ret; |
| 151 | struct lttng_ht_iter iter; |
| 152 | |
| 153 | assert(stream); |
| 154 | |
| 155 | rcu_read_lock(); |
| 156 | |
| 157 | if (ht) { |
| 158 | iter.iter.node = &stream->node.node; |
| 159 | ret = lttng_ht_del(ht, &iter); |
| 160 | assert(!ret); |
| 161 | } |
| 162 | |
| 163 | /* Delete from stream per channel ID hash table. */ |
| 164 | iter.iter.node = &stream->node_channel_id.node; |
| 165 | /* |
| 166 | * The returned value is of no importance. Even if the node is NOT in the |
| 167 | * hash table, we continue since we may have been called by a code path |
| 168 | * that did not add the stream to a (all) hash table. Same goes for the |
| 169 | * next call ht del call. |
| 170 | */ |
| 171 | (void) lttng_ht_del(consumer_data.stream_per_chan_id_ht, &iter); |
| 172 | |
| 173 | /* Delete from the global stream list. */ |
| 174 | iter.iter.node = &stream->node_session_id.node; |
| 175 | /* See the previous ht del on why we ignore the returned value. */ |
| 176 | (void) lttng_ht_del(consumer_data.stream_list_ht, &iter); |
| 177 | |
| 178 | rcu_read_unlock(); |
| 179 | |
| 180 | /* |
| 181 | * For a *non* monitored stream, we MUST NOT decrement or else the data |
| 182 | * thread will use the wrong value or stream for its local stream set. |
| 183 | */ |
| 184 | if (stream->chan->monitor) { |
| 185 | /* Decrement the stream count of the global consumer data. */ |
| 186 | assert(consumer_data.stream_count > 0); |
| 187 | consumer_data.stream_count--; |
| 188 | } |
| 189 | } |
| 190 | |
| 191 | /* |
| 192 | * Free the given stream within a RCU call. |
| 193 | */ |
| 194 | void consumer_stream_free(struct lttng_consumer_stream *stream) |
| 195 | { |
| 196 | assert(stream); |
| 197 | |
| 198 | call_rcu(&stream->node.head, free_stream_rcu); |
| 199 | } |
| 200 | |
| 201 | /* |
| 202 | * Destroy a stream completely. This will delete, close and free the stream. |
| 203 | * Once return, the stream is NO longer usable. Its channel may get destroyed |
| 204 | * if conditions are met. |
| 205 | * |
| 206 | * This MUST be called WITHOUT the consumer data and stream lock acquired. |
| 207 | */ |
| 208 | void consumer_stream_destroy(struct lttng_consumer_stream *stream, |
| 209 | struct lttng_ht *ht) |
| 210 | { |
| 211 | struct lttng_consumer_channel *free_chan = NULL; |
| 212 | |
| 213 | assert(stream); |
| 214 | |
| 215 | DBG("Consumer stream destroy - wait_fd: %d", stream->wait_fd); |
| 216 | |
| 217 | pthread_mutex_lock(&consumer_data.lock); |
| 218 | pthread_mutex_lock(&stream->lock); |
| 219 | |
| 220 | /* Remove every reference of the stream in the consumer. */ |
| 221 | consumer_stream_delete(stream, ht); |
| 222 | |
| 223 | /* Close down everything including the relayd if one. */ |
| 224 | consumer_stream_close(stream); |
| 225 | |
| 226 | /* Update refcount of channel and see if we need to destroy it. */ |
| 227 | if (!uatomic_sub_return(&stream->chan->refcount, 1) |
| 228 | && !uatomic_read(&stream->chan->nb_init_stream_left)) { |
| 229 | free_chan = stream->chan; |
| 230 | } |
| 231 | |
| 232 | /* Indicates that the consumer data state MUST be updated after this. */ |
| 233 | consumer_data.need_update = 1; |
| 234 | |
| 235 | pthread_mutex_unlock(&stream->lock); |
| 236 | pthread_mutex_unlock(&consumer_data.lock); |
| 237 | |
| 238 | if (free_chan) { |
| 239 | consumer_del_channel(free_chan); |
| 240 | } |
| 241 | |
| 242 | /* Free stream within a RCU call. */ |
| 243 | consumer_stream_free(stream); |
| 244 | } |