| 1 | /* |
| 2 | * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com> |
| 3 | * David Goulet <dgoulet@efficios.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License, version 2 only, |
| 7 | * as published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 12 | * more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License along |
| 15 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 16 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | */ |
| 18 | |
| 19 | #define _GNU_SOURCE |
| 20 | #include <assert.h> |
| 21 | #include <pthread.h> |
| 22 | #include <stdlib.h> |
| 23 | #include <string.h> |
| 24 | #include <sys/types.h> |
| 25 | #include <unistd.h> |
| 26 | #include <inttypes.h> |
| 27 | |
| 28 | #include <common/common.h> |
| 29 | #include <common/utils.h> |
| 30 | #include <common/sessiond-comm/sessiond-comm.h> |
| 31 | #include <common/ust-consumer/ust-consumer.h> |
| 32 | #include <common/consumer.h> |
| 33 | |
| 34 | #include "consumer-metadata-cache.h" |
| 35 | |
| 36 | extern struct lttng_consumer_global_data consumer_data; |
| 37 | |
| 38 | /* |
| 39 | * Extend the allocated size of the metadata cache. Called only from |
| 40 | * lttng_ustconsumer_write_metadata_cache. |
| 41 | * |
| 42 | * Return 0 on success, a negative value on error. |
| 43 | */ |
| 44 | static int extend_metadata_cache(struct lttng_consumer_channel *channel, |
| 45 | unsigned int size) |
| 46 | { |
| 47 | int ret = 0; |
| 48 | char *tmp_data_ptr; |
| 49 | unsigned int new_size; |
| 50 | |
| 51 | assert(channel); |
| 52 | assert(channel->metadata_cache); |
| 53 | |
| 54 | new_size = max_t(unsigned int, |
| 55 | channel->metadata_cache->cache_alloc_size + size, |
| 56 | channel->metadata_cache->cache_alloc_size << 1); |
| 57 | DBG("Extending metadata cache to %u", new_size); |
| 58 | tmp_data_ptr = realloc(channel->metadata_cache->data, new_size); |
| 59 | if (!tmp_data_ptr) { |
| 60 | ERR("Reallocating metadata cache"); |
| 61 | free(channel->metadata_cache->data); |
| 62 | ret = -1; |
| 63 | goto end; |
| 64 | } |
| 65 | channel->metadata_cache->data = tmp_data_ptr; |
| 66 | channel->metadata_cache->cache_alloc_size = new_size; |
| 67 | |
| 68 | end: |
| 69 | return ret; |
| 70 | } |
| 71 | |
| 72 | /* |
| 73 | * Write metadata to the cache, extend the cache if necessary. We support |
| 74 | * non-contiguous updates but not overlapping ones. If there is contiguous |
| 75 | * metadata in the cache, we send it to the ring buffer. The metadata cache |
| 76 | * lock MUST be acquired to write in the cache. |
| 77 | * |
| 78 | * Return 0 on success, a negative value on error. |
| 79 | */ |
| 80 | int consumer_metadata_cache_write(struct lttng_consumer_channel *channel, |
| 81 | unsigned int offset, unsigned int len, char *data) |
| 82 | { |
| 83 | int ret = 0; |
| 84 | struct consumer_metadata_cache *cache; |
| 85 | |
| 86 | assert(channel); |
| 87 | assert(channel->metadata_cache); |
| 88 | |
| 89 | cache = channel->metadata_cache; |
| 90 | DBG("Writing %u bytes from offset %u in metadata cache", len, offset); |
| 91 | |
| 92 | if (offset + len > cache->cache_alloc_size) { |
| 93 | ret = extend_metadata_cache(channel, |
| 94 | len - cache->cache_alloc_size + offset); |
| 95 | if (ret < 0) { |
| 96 | ERR("Extending metadata cache"); |
| 97 | goto end; |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | memcpy(cache->data + offset, data, len); |
| 102 | cache->total_bytes_written += len; |
| 103 | if (offset + len > cache->max_offset) { |
| 104 | cache->max_offset = offset + len; |
| 105 | } |
| 106 | |
| 107 | if (cache->max_offset == cache->total_bytes_written) { |
| 108 | char dummy = 'c'; |
| 109 | |
| 110 | cache->contiguous = cache->max_offset; |
| 111 | if (channel->monitor) { |
| 112 | ret = write(channel->metadata_stream->ust_metadata_poll_pipe[1], |
| 113 | &dummy, 1); |
| 114 | if (ret < 1) { |
| 115 | ERR("Wakeup UST metadata pipe"); |
| 116 | goto end; |
| 117 | } |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | end: |
| 122 | return ret; |
| 123 | } |
| 124 | |
| 125 | /* |
| 126 | * Create the metadata cache, original allocated size: max_sb_size |
| 127 | * |
| 128 | * Return 0 on success, a negative value on error. |
| 129 | */ |
| 130 | int consumer_metadata_cache_allocate(struct lttng_consumer_channel *channel) |
| 131 | { |
| 132 | int ret; |
| 133 | |
| 134 | assert(channel); |
| 135 | |
| 136 | channel->metadata_cache = zmalloc( |
| 137 | sizeof(struct consumer_metadata_cache)); |
| 138 | if (!channel->metadata_cache) { |
| 139 | PERROR("zmalloc metadata cache struct"); |
| 140 | ret = -1; |
| 141 | goto end; |
| 142 | } |
| 143 | ret = pthread_mutex_init(&channel->metadata_cache->lock, NULL); |
| 144 | if (ret != 0) { |
| 145 | PERROR("mutex init"); |
| 146 | goto end_free_cache; |
| 147 | } |
| 148 | |
| 149 | channel->metadata_cache->cache_alloc_size = DEFAULT_METADATA_CACHE_SIZE; |
| 150 | channel->metadata_cache->data = zmalloc( |
| 151 | channel->metadata_cache->cache_alloc_size * sizeof(char)); |
| 152 | if (!channel->metadata_cache->data) { |
| 153 | PERROR("zmalloc metadata cache data"); |
| 154 | ret = -1; |
| 155 | goto end_free_mutex; |
| 156 | } |
| 157 | DBG("Allocated metadata cache of %" PRIu64 " bytes", |
| 158 | channel->metadata_cache->cache_alloc_size); |
| 159 | |
| 160 | ret = 0; |
| 161 | goto end; |
| 162 | |
| 163 | end_free_mutex: |
| 164 | pthread_mutex_destroy(&channel->metadata_cache->lock); |
| 165 | end_free_cache: |
| 166 | free(channel->metadata_cache); |
| 167 | end: |
| 168 | return ret; |
| 169 | } |
| 170 | |
| 171 | /* |
| 172 | * Destroy and free the metadata cache |
| 173 | */ |
| 174 | void consumer_metadata_cache_destroy(struct lttng_consumer_channel *channel) |
| 175 | { |
| 176 | if (!channel || !channel->metadata_cache) { |
| 177 | return; |
| 178 | } |
| 179 | |
| 180 | DBG("Destroying metadata cache"); |
| 181 | |
| 182 | pthread_mutex_destroy(&channel->metadata_cache->lock); |
| 183 | free(channel->metadata_cache->data); |
| 184 | free(channel->metadata_cache); |
| 185 | } |
| 186 | |
| 187 | /* |
| 188 | * Check if the cache is flushed up to the offset passed in parameter. |
| 189 | * |
| 190 | * Return 0 if everything has been flushed, 1 if there is data not flushed. |
| 191 | */ |
| 192 | int consumer_metadata_cache_flushed(struct lttng_consumer_channel *channel, |
| 193 | uint64_t offset, int timer) |
| 194 | { |
| 195 | int ret = 0; |
| 196 | struct lttng_consumer_stream *metadata_stream; |
| 197 | |
| 198 | assert(channel); |
| 199 | assert(channel->metadata_cache); |
| 200 | |
| 201 | /* |
| 202 | * If not called from a timer handler, we have to take the |
| 203 | * channel lock to be mutually exclusive with channel teardown. |
| 204 | * Timer handler does not need to take this lock because it is |
| 205 | * already synchronized by timer stop (and, more importantly, |
| 206 | * taking this lock in a timer handler would cause a deadlock). |
| 207 | */ |
| 208 | if (!timer) { |
| 209 | pthread_mutex_lock(&channel->lock); |
| 210 | } |
| 211 | pthread_mutex_lock(&channel->timer_lock); |
| 212 | pthread_mutex_lock(&channel->metadata_cache->lock); |
| 213 | |
| 214 | metadata_stream = channel->metadata_stream; |
| 215 | |
| 216 | if (!metadata_stream) { |
| 217 | /* |
| 218 | * Having no metadata stream means the channel is being destroyed so there |
| 219 | * is no cache to flush anymore. |
| 220 | */ |
| 221 | ret = 0; |
| 222 | } else if (metadata_stream->ust_metadata_pushed >= offset) { |
| 223 | ret = 0; |
| 224 | } else if (channel->metadata_stream->endpoint_status != |
| 225 | CONSUMER_ENDPOINT_ACTIVE) { |
| 226 | /* An inactive endpoint means we don't have to flush anymore. */ |
| 227 | ret = 0; |
| 228 | } else { |
| 229 | /* Still not completely flushed. */ |
| 230 | ret = 1; |
| 231 | } |
| 232 | |
| 233 | pthread_mutex_unlock(&channel->metadata_cache->lock); |
| 234 | pthread_mutex_unlock(&channel->timer_lock); |
| 235 | if (!timer) { |
| 236 | pthread_mutex_unlock(&channel->lock); |
| 237 | } |
| 238 | |
| 239 | return ret; |
| 240 | } |