consumerd: clean-up: stream attribute accessed without locking stream
[lttng-tools.git] / src / common / consumer / consumer-metadata-cache.c
CommitLineData
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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
6c1c0768 19#define _LGPL_SOURCE
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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>
c8fea79c 32#include <common/consumer/consumer.h>
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33
34#include "consumer-metadata-cache.h"
35
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36extern struct lttng_consumer_global_data consumer_data;
37
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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 */
44static int extend_metadata_cache(struct lttng_consumer_channel *channel,
45 unsigned int size)
46{
47 int ret = 0;
48 char *tmp_data_ptr;
53efb85a 49 unsigned int new_size, old_size;
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50
51 assert(channel);
52 assert(channel->metadata_cache);
53
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54 old_size = channel->metadata_cache->cache_alloc_size;
55 new_size = max_t(unsigned int, old_size + size, old_size << 1);
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56 DBG("Extending metadata cache to %u", new_size);
57 tmp_data_ptr = realloc(channel->metadata_cache->data, new_size);
58 if (!tmp_data_ptr) {
59 ERR("Reallocating metadata cache");
60 free(channel->metadata_cache->data);
61 ret = -1;
62 goto end;
63 }
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64 /* Zero newly allocated memory */
65 memset(tmp_data_ptr + old_size, 0, new_size - old_size);
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66 channel->metadata_cache->data = tmp_data_ptr;
67 channel->metadata_cache->cache_alloc_size = new_size;
68
69end:
70 return ret;
71}
72
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73/*
74 * Reset the metadata cache.
75 */
76static
77void metadata_cache_reset(struct consumer_metadata_cache *cache)
78{
79 memset(cache->data, 0, cache->cache_alloc_size);
80 cache->max_offset = 0;
81}
82
83/*
84 * Check if the metadata cache version changed.
85 * If it did, reset the metadata cache.
86 * The metadata cache lock MUST be held.
87 *
88 * Returns 0 on success, a negative value on error.
89 */
90static
91int metadata_cache_check_version(struct consumer_metadata_cache *cache,
9dd04ae3 92 uint64_t version)
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93{
94 int ret = 0;
95
96 if (cache->version == version) {
97 goto end;
98 }
99
100 DBG("Metadata cache version update to %" PRIu64, version);
101 metadata_cache_reset(cache);
102 cache->version = version;
103
104end:
105 return ret;
106}
107
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108/*
109 * Write a character on the metadata poll pipe to wake the metadata thread.
110 * Returns 0 on success, -1 on error.
111 */
112int consumer_metadata_wakeup_pipe(const struct lttng_consumer_channel *channel)
113{
114 int ret = 0;
115 const char dummy = 'c';
116
117 if (channel->monitor && channel->metadata_stream) {
118 ssize_t write_ret;
119
120 write_ret = lttng_write(channel->metadata_stream->ust_metadata_poll_pipe[1],
121 &dummy, 1);
122 if (write_ret < 1) {
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123 if (errno == EWOULDBLOCK) {
124 /*
125 * This is fine, the metadata poll thread
126 * is having a hard time keeping-up, but
127 * it will eventually wake-up and consume
128 * the available data.
129 */
130 ret = 0;
131 } else {
132 PERROR("Wake-up UST metadata pipe");
133 ret = -1;
134 goto end;
135 }
136 }
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137 }
138
139end:
140 return ret;
141}
142
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143/*
144 * Write metadata to the cache, extend the cache if necessary. We support
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145 * overlapping updates, but they need to be contiguous. Send the
146 * contiguous metadata in cache to the ring buffer. The metadata cache
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147 * lock MUST be acquired to write in the cache.
148 *
149 * Return 0 on success, a negative value on error.
150 */
151int consumer_metadata_cache_write(struct lttng_consumer_channel *channel,
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152 unsigned int offset, unsigned int len, uint64_t version,
153 char *data)
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154{
155 int ret = 0;
156 struct consumer_metadata_cache *cache;
157
158 assert(channel);
159 assert(channel->metadata_cache);
160
161 cache = channel->metadata_cache;
93ec662e 162
9dd04ae3 163 ret = metadata_cache_check_version(cache, version);
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164 if (ret < 0) {
165 goto end;
166 }
167
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168 DBG("Writing %u bytes from offset %u in metadata cache", len, offset);
169
170 if (offset + len > cache->cache_alloc_size) {
171 ret = extend_metadata_cache(channel,
172 len - cache->cache_alloc_size + offset);
173 if (ret < 0) {
174 ERR("Extending metadata cache");
175 goto end;
176 }
177 }
178
179 memcpy(cache->data + offset, data, len);
331744e3 180 if (offset + len > cache->max_offset) {
c585821b 181 cache->max_offset = offset + len;
5b8eb761 182 ret = consumer_metadata_wakeup_pipe(channel);
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183 }
184
185end:
186 return ret;
187}
188
189/*
190 * Create the metadata cache, original allocated size: max_sb_size
191 *
192 * Return 0 on success, a negative value on error.
193 */
194int consumer_metadata_cache_allocate(struct lttng_consumer_channel *channel)
195{
196 int ret;
197
198 assert(channel);
199
200 channel->metadata_cache = zmalloc(
201 sizeof(struct consumer_metadata_cache));
202 if (!channel->metadata_cache) {
203 PERROR("zmalloc metadata cache struct");
204 ret = -1;
205 goto end;
206 }
207 ret = pthread_mutex_init(&channel->metadata_cache->lock, NULL);
208 if (ret != 0) {
209 PERROR("mutex init");
210 goto end_free_cache;
211 }
212
213 channel->metadata_cache->cache_alloc_size = DEFAULT_METADATA_CACHE_SIZE;
214 channel->metadata_cache->data = zmalloc(
215 channel->metadata_cache->cache_alloc_size * sizeof(char));
216 if (!channel->metadata_cache->data) {
217 PERROR("zmalloc metadata cache data");
218 ret = -1;
219 goto end_free_mutex;
220 }
221 DBG("Allocated metadata cache of %" PRIu64 " bytes",
222 channel->metadata_cache->cache_alloc_size);
223
224 ret = 0;
225 goto end;
226
227end_free_mutex:
228 pthread_mutex_destroy(&channel->metadata_cache->lock);
229end_free_cache:
230 free(channel->metadata_cache);
231end:
232 return ret;
233}
234
235/*
236 * Destroy and free the metadata cache
237 */
238void consumer_metadata_cache_destroy(struct lttng_consumer_channel *channel)
239{
240 if (!channel || !channel->metadata_cache) {
241 return;
242 }
243
244 DBG("Destroying metadata cache");
245
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246 pthread_mutex_destroy(&channel->metadata_cache->lock);
247 free(channel->metadata_cache->data);
248 free(channel->metadata_cache);
249}
250
251/*
252 * Check if the cache is flushed up to the offset passed in parameter.
253 *
254 * Return 0 if everything has been flushed, 1 if there is data not flushed.
255 */
256int consumer_metadata_cache_flushed(struct lttng_consumer_channel *channel,
5e41ebe1 257 uint64_t offset, int timer)
331744e3 258{
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259 int ret = 0;
260 struct lttng_consumer_stream *metadata_stream;
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261
262 assert(channel);
263 assert(channel->metadata_cache);
264
7f725ec5 265 /*
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266 * If not called from a timer handler, we have to take the
267 * channel lock to be mutually exclusive with channel teardown.
268 * Timer handler does not need to take this lock because it is
269 * already synchronized by timer stop (and, more importantly,
270 * taking this lock in a timer handler would cause a deadlock).
7f725ec5 271 */
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272 if (!timer) {
273 pthread_mutex_lock(&channel->lock);
274 }
ec6ea7d0 275 pthread_mutex_lock(&channel->timer_lock);
04ef1097 276 metadata_stream = channel->metadata_stream;
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277 pthread_mutex_lock(&metadata_stream->lock);
278 pthread_mutex_lock(&channel->metadata_cache->lock);
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279
280 if (!metadata_stream) {
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281 /*
282 * Having no metadata stream means the channel is being destroyed so there
283 * is no cache to flush anymore.
284 */
285 ret = 0;
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286 } else if (metadata_stream->ust_metadata_pushed >= offset) {
287 ret = 0;
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288 } else if (channel->metadata_stream->endpoint_status !=
289 CONSUMER_ENDPOINT_ACTIVE) {
290 /* An inactive endpoint means we don't have to flush anymore. */
291 ret = 0;
331744e3 292 } else {
fe81e5c9 293 /* Still not completely flushed. */
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294 ret = 1;
295 }
fe81e5c9 296
331744e3 297 pthread_mutex_unlock(&channel->metadata_cache->lock);
8e1ef46e 298 pthread_mutex_unlock(&metadata_stream->lock);
ec6ea7d0 299 pthread_mutex_unlock(&channel->timer_lock);
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300 if (!timer) {
301 pthread_mutex_unlock(&channel->lock);
302 }
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303
304 return ret;
305}
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