2 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
3 * David Goulet <dgoulet@efficios.com>
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.
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
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.
24 #include <sys/types.h>
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/consumer.h>
34 #include "consumer-metadata-cache.h"
36 extern struct lttng_consumer_global_data consumer_data
;
39 * Extend the allocated size of the metadata cache. Called only from
40 * lttng_ustconsumer_write_metadata_cache.
42 * Return 0 on success, a negative value on error.
44 static int extend_metadata_cache(struct lttng_consumer_channel
*channel
,
49 unsigned int new_size
, old_size
;
52 assert(channel
->metadata_cache
);
54 old_size
= channel
->metadata_cache
->cache_alloc_size
;
55 new_size
= max_t(unsigned int, old_size
+ size
, old_size
<< 1);
56 DBG("Extending metadata cache to %u", new_size
);
57 tmp_data_ptr
= realloc(channel
->metadata_cache
->data
, new_size
);
59 ERR("Reallocating metadata cache");
60 free(channel
->metadata_cache
->data
);
64 /* Zero newly allocated memory */
65 memset(tmp_data_ptr
+ old_size
, 0, new_size
- old_size
);
66 channel
->metadata_cache
->data
= tmp_data_ptr
;
67 channel
->metadata_cache
->cache_alloc_size
= new_size
;
74 * Reset the metadata cache.
77 void metadata_cache_reset(struct consumer_metadata_cache
*cache
)
79 memset(cache
->data
, 0, cache
->cache_alloc_size
);
80 cache
->max_offset
= 0;
84 * Check if the metadata cache version changed.
85 * If it did, reset the metadata cache.
86 * The metadata cache lock MUST be held.
88 * Returns 0 on success, a negative value on error.
91 int metadata_cache_check_version(struct consumer_metadata_cache
*cache
,
92 struct lttng_consumer_channel
*channel
, uint64_t version
)
96 if (cache
->version
== version
) {
100 DBG("Metadata cache version update to %" PRIu64
, version
);
101 metadata_cache_reset(cache
);
102 cache
->version
= version
;
109 * Write a character on the metadata poll pipe to wake the metadata thread.
110 * Returns 0 on success, -1 on error.
112 int consumer_metadata_wakeup_pipe(struct lttng_consumer_channel
*channel
)
118 if (channel
->monitor
&& channel
->metadata_stream
) {
119 size_ret
= lttng_write(channel
->metadata_stream
->ust_metadata_poll_pipe
[1],
122 ERR("Wakeup UST metadata pipe");
133 * Write metadata to the cache, extend the cache if necessary. We support
134 * overlapping updates, but they need to be contiguous. Send the
135 * contiguous metadata in cache to the ring buffer. The metadata cache
136 * lock MUST be acquired to write in the cache.
138 * Return 0 on success, a negative value on error.
140 int consumer_metadata_cache_write(struct lttng_consumer_channel
*channel
,
141 unsigned int offset
, unsigned int len
, uint64_t version
,
145 struct consumer_metadata_cache
*cache
;
148 assert(channel
->metadata_cache
);
150 cache
= channel
->metadata_cache
;
152 ret
= metadata_cache_check_version(cache
, channel
, version
);
157 DBG("Writing %u bytes from offset %u in metadata cache", len
, offset
);
159 if (offset
+ len
> cache
->cache_alloc_size
) {
160 ret
= extend_metadata_cache(channel
,
161 len
- cache
->cache_alloc_size
+ offset
);
163 ERR("Extending metadata cache");
168 memcpy(cache
->data
+ offset
, data
, len
);
169 if (offset
+ len
> cache
->max_offset
) {
170 cache
->max_offset
= offset
+ len
;
171 ret
= consumer_metadata_wakeup_pipe(channel
);
179 * Create the metadata cache, original allocated size: max_sb_size
181 * Return 0 on success, a negative value on error.
183 int consumer_metadata_cache_allocate(struct lttng_consumer_channel
*channel
)
189 channel
->metadata_cache
= zmalloc(
190 sizeof(struct consumer_metadata_cache
));
191 if (!channel
->metadata_cache
) {
192 PERROR("zmalloc metadata cache struct");
196 ret
= pthread_mutex_init(&channel
->metadata_cache
->lock
, NULL
);
198 PERROR("mutex init");
202 channel
->metadata_cache
->cache_alloc_size
= DEFAULT_METADATA_CACHE_SIZE
;
203 channel
->metadata_cache
->data
= zmalloc(
204 channel
->metadata_cache
->cache_alloc_size
* sizeof(char));
205 if (!channel
->metadata_cache
->data
) {
206 PERROR("zmalloc metadata cache data");
210 DBG("Allocated metadata cache of %" PRIu64
" bytes",
211 channel
->metadata_cache
->cache_alloc_size
);
217 pthread_mutex_destroy(&channel
->metadata_cache
->lock
);
219 free(channel
->metadata_cache
);
225 * Destroy and free the metadata cache
227 void consumer_metadata_cache_destroy(struct lttng_consumer_channel
*channel
)
229 if (!channel
|| !channel
->metadata_cache
) {
233 DBG("Destroying metadata cache");
235 pthread_mutex_destroy(&channel
->metadata_cache
->lock
);
236 free(channel
->metadata_cache
->data
);
237 free(channel
->metadata_cache
);
241 * Check if the cache is flushed up to the offset passed in parameter.
243 * Return 0 if everything has been flushed, 1 if there is data not flushed.
245 int consumer_metadata_cache_flushed(struct lttng_consumer_channel
*channel
,
246 uint64_t offset
, int timer
)
249 struct lttng_consumer_stream
*metadata_stream
;
252 assert(channel
->metadata_cache
);
255 * If not called from a timer handler, we have to take the
256 * channel lock to be mutually exclusive with channel teardown.
257 * Timer handler does not need to take this lock because it is
258 * already synchronized by timer stop (and, more importantly,
259 * taking this lock in a timer handler would cause a deadlock).
262 pthread_mutex_lock(&channel
->lock
);
264 pthread_mutex_lock(&channel
->timer_lock
);
265 pthread_mutex_lock(&channel
->metadata_cache
->lock
);
267 metadata_stream
= channel
->metadata_stream
;
269 if (!metadata_stream
) {
271 * Having no metadata stream means the channel is being destroyed so there
272 * is no cache to flush anymore.
275 } else if (metadata_stream
->ust_metadata_pushed
>= offset
) {
277 } else if (channel
->metadata_stream
->endpoint_status
!=
278 CONSUMER_ENDPOINT_ACTIVE
) {
279 /* An inactive endpoint means we don't have to flush anymore. */
282 /* Still not completely flushed. */
286 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
287 pthread_mutex_unlock(&channel
->timer_lock
);
289 pthread_mutex_unlock(&channel
->lock
);