2 * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
3 * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
5 * SPDX-License-Identifier: GPL-2.0-only
13 #include <sys/types.h>
17 #include <common/common.h>
18 #include <common/utils.h>
19 #include <common/sessiond-comm/sessiond-comm.h>
20 #include <common/ust-consumer/ust-consumer.h>
21 #include <common/consumer/consumer.h>
23 #include "consumer-metadata-cache.h"
25 enum metadata_cache_update_version_status
{
26 METADATA_CACHE_UPDATE_STATUS_VERSION_UPDATED
,
27 METADATA_CACHE_UPDATE_STATUS_VERSION_NOT_UPDATED
,
30 extern struct lttng_consumer_global_data the_consumer_data
;
33 * Reset the metadata cache.
36 void metadata_cache_reset(struct consumer_metadata_cache
*cache
)
38 const int ret
= lttng_dynamic_buffer_set_size(&cache
->contents
, 0);
40 LTTNG_ASSERT(ret
== 0);
44 * Check if the metadata cache version changed.
45 * If it did, reset the metadata cache.
46 * The metadata cache lock MUST be held.
48 static enum metadata_cache_update_version_status
metadata_cache_update_version(
49 struct consumer_metadata_cache
*cache
, uint64_t version
)
51 enum metadata_cache_update_version_status status
;
53 if (cache
->version
== version
) {
54 status
= METADATA_CACHE_UPDATE_STATUS_VERSION_NOT_UPDATED
;
58 DBG("Metadata cache version update to %" PRIu64
, version
);
59 cache
->version
= version
;
60 status
= METADATA_CACHE_UPDATE_STATUS_VERSION_UPDATED
;
67 * Write metadata to the cache, extend the cache if necessary. We support
68 * overlapping updates, but they need to be contiguous. Send the
69 * contiguous metadata in cache to the ring buffer. The metadata cache
70 * lock MUST be acquired to write in the cache.
72 * See `enum consumer_metadata_cache_write_status` for the meaning of the
73 * various returned status codes.
75 enum consumer_metadata_cache_write_status
76 consumer_metadata_cache_write(struct consumer_metadata_cache
*cache
,
77 unsigned int offset
, unsigned int len
, uint64_t version
,
81 enum consumer_metadata_cache_write_status status
;
82 bool cache_is_invalidated
= false;
83 uint64_t original_size
;
86 ASSERT_LOCKED(cache
->lock
);
87 original_size
= cache
->contents
.size
;
89 if (metadata_cache_update_version(cache
, version
) ==
90 METADATA_CACHE_UPDATE_STATUS_VERSION_UPDATED
) {
91 metadata_cache_reset(cache
);
92 cache_is_invalidated
= true;
95 DBG("Writing %u bytes from offset %u in metadata cache", len
, offset
);
96 if (offset
+ len
> cache
->contents
.size
) {
97 ret
= lttng_dynamic_buffer_set_size(
98 &cache
->contents
, offset
+ len
);
100 ERR("Extending metadata cache");
101 status
= CONSUMER_METADATA_CACHE_WRITE_STATUS_ERROR
;
106 memcpy(cache
->contents
.data
+ offset
, data
, len
);
108 if (cache_is_invalidated
) {
109 status
= CONSUMER_METADATA_CACHE_WRITE_STATUS_INVALIDATED
;
110 } else if (cache
->contents
.size
> original_size
) {
111 status
= CONSUMER_METADATA_CACHE_WRITE_STATUS_APPENDED_CONTENT
;
113 status
= CONSUMER_METADATA_CACHE_WRITE_STATUS_NO_CHANGE
;
114 LTTNG_ASSERT(cache
->contents
.size
== original_size
);
122 * Create the metadata cache, original allocated size: max_sb_size
124 * Return 0 on success, a negative value on error.
126 int consumer_metadata_cache_allocate(struct lttng_consumer_channel
*channel
)
130 LTTNG_ASSERT(channel
);
132 channel
->metadata_cache
= (consumer_metadata_cache
*) zmalloc(
133 sizeof(struct consumer_metadata_cache
));
134 if (!channel
->metadata_cache
) {
135 PERROR("zmalloc metadata cache struct");
139 ret
= pthread_mutex_init(&channel
->metadata_cache
->lock
, NULL
);
141 PERROR("mutex init");
145 lttng_dynamic_buffer_init(&channel
->metadata_cache
->contents
);
146 ret
= lttng_dynamic_buffer_set_capacity(
147 &channel
->metadata_cache
->contents
,
148 DEFAULT_METADATA_CACHE_SIZE
);
150 PERROR("Failed to pre-allocate metadata cache storage of %d bytes on creation",
151 DEFAULT_METADATA_CACHE_SIZE
);
156 DBG("Allocated metadata cache: current capacity = %zu",
157 lttng_dynamic_buffer_get_capacity_left(
158 &channel
->metadata_cache
->contents
));
164 pthread_mutex_destroy(&channel
->metadata_cache
->lock
);
166 free(channel
->metadata_cache
);
172 * Destroy and free the metadata cache
174 void consumer_metadata_cache_destroy(struct lttng_consumer_channel
*channel
)
176 if (!channel
|| !channel
->metadata_cache
) {
180 DBG("Destroying metadata cache");
182 pthread_mutex_destroy(&channel
->metadata_cache
->lock
);
183 lttng_dynamic_buffer_reset(&channel
->metadata_cache
->contents
);
184 free(channel
->metadata_cache
);
188 * Check if the cache is flushed up to the offset passed in parameter.
190 * Return 0 if everything has been flushed, 1 if there is data not flushed.
192 int consumer_metadata_cache_flushed(struct lttng_consumer_channel
*channel
,
193 uint64_t offset
, int timer
)
196 struct lttng_consumer_stream
*metadata_stream
;
198 LTTNG_ASSERT(channel
);
199 LTTNG_ASSERT(channel
->metadata_cache
);
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).
209 pthread_mutex_lock(&channel
->lock
);
211 pthread_mutex_lock(&channel
->timer_lock
);
212 metadata_stream
= channel
->metadata_stream
;
213 if (!metadata_stream
) {
215 * Having no metadata stream means the channel is being destroyed so there
216 * is no cache to flush anymore.
219 goto end_unlock_channel
;
222 pthread_mutex_lock(&metadata_stream
->lock
);
223 pthread_mutex_lock(&channel
->metadata_cache
->lock
);
225 if (metadata_stream
->ust_metadata_pushed
>= offset
) {
227 } else if (channel
->metadata_stream
->endpoint_status
!=
228 CONSUMER_ENDPOINT_ACTIVE
) {
229 /* An inactive endpoint means we don't have to flush anymore. */
232 /* Still not completely flushed. */
236 pthread_mutex_unlock(&channel
->metadata_cache
->lock
);
237 pthread_mutex_unlock(&metadata_stream
->lock
);
239 pthread_mutex_unlock(&channel
->timer_lock
);
241 pthread_mutex_unlock(&channel
->lock
);