/*
- * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
- * David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
+ * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License, version 2 only,
- * as published by the Free Software Foundation.
+ * SPDX-License-Identifier: GPL-2.0-only
*
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#define _LGPL_SOURCE
#include "consumer-metadata-cache.h"
+enum metadata_cache_update_version_status {
+ METADATA_CACHE_UPDATE_STATUS_VERSION_UPDATED,
+ METADATA_CACHE_UPDATE_STATUS_VERSION_NOT_UPDATED,
+};
+
extern struct lttng_consumer_global_data consumer_data;
/*
* Check if the metadata cache version changed.
* If it did, reset the metadata cache.
* The metadata cache lock MUST be held.
- *
- * Returns 0 on success, a negative value on error.
*/
-static
-int metadata_cache_check_version(struct consumer_metadata_cache *cache,
- uint64_t version)
+static enum metadata_cache_update_version_status metadata_cache_update_version(
+ struct consumer_metadata_cache *cache, uint64_t version)
{
- int ret = 0;
+ enum metadata_cache_update_version_status status;
if (cache->version == version) {
+ status = METADATA_CACHE_UPDATE_STATUS_VERSION_NOT_UPDATED;
goto end;
}
DBG("Metadata cache version update to %" PRIu64, version);
- metadata_cache_reset(cache);
cache->version = version;
+ status = METADATA_CACHE_UPDATE_STATUS_VERSION_UPDATED;
end:
- return ret;
-}
-
-/*
- * Write a character on the metadata poll pipe to wake the metadata thread.
- * Returns 0 on success, -1 on error.
- */
-int consumer_metadata_wakeup_pipe(const struct lttng_consumer_channel *channel)
-{
- int ret = 0;
- const char dummy = 'c';
-
- if (channel->monitor && channel->metadata_stream) {
- ssize_t write_ret;
-
- write_ret = lttng_write(channel->metadata_stream->ust_metadata_poll_pipe[1],
- &dummy, 1);
- if (write_ret < 1) {
- if (errno == EWOULDBLOCK) {
- /*
- * This is fine, the metadata poll thread
- * is having a hard time keeping-up, but
- * it will eventually wake-up and consume
- * the available data.
- */
- ret = 0;
- } else {
- PERROR("Wake-up UST metadata pipe");
- ret = -1;
- goto end;
- }
- }
- }
-
-end:
- return ret;
+ return status;
}
/*
* contiguous metadata in cache to the ring buffer. The metadata cache
* lock MUST be acquired to write in the cache.
*
- * Return 0 on success, a negative value on error.
+ * See `enum consumer_metadata_cache_write_status` for the meaning of the
+ * various returned status codes.
*/
-int consumer_metadata_cache_write(struct lttng_consumer_channel *channel,
+enum consumer_metadata_cache_write_status
+consumer_metadata_cache_write(struct lttng_consumer_channel *channel,
unsigned int offset, unsigned int len, uint64_t version,
- char *data)
+ const char *data)
{
int ret = 0;
struct consumer_metadata_cache *cache;
+ enum consumer_metadata_cache_write_status status;
+ bool cache_is_invalidated = false;
+ uint64_t original_max_offset;
assert(channel);
assert(channel->metadata_cache);
cache = channel->metadata_cache;
+ ASSERT_LOCKED(cache->lock);
+ original_max_offset = cache->max_offset;
- ret = metadata_cache_check_version(cache, version);
- if (ret < 0) {
- goto end;
+ if (metadata_cache_update_version(cache, version) ==
+ METADATA_CACHE_UPDATE_STATUS_VERSION_UPDATED) {
+ metadata_cache_reset(cache);
+ cache_is_invalidated = true;
}
DBG("Writing %u bytes from offset %u in metadata cache", len, offset);
len - cache->cache_alloc_size + offset);
if (ret < 0) {
ERR("Extending metadata cache");
+ status = CONSUMER_METADATA_CACHE_WRITE_STATUS_ERROR;
goto end;
}
}
memcpy(cache->data + offset, data, len);
- if (offset + len > cache->max_offset) {
- cache->max_offset = offset + len;
- ret = consumer_metadata_wakeup_pipe(channel);
+ cache->max_offset = max(cache->max_offset, offset + len);
+
+ if (cache_is_invalidated) {
+ status = CONSUMER_METADATA_CACHE_WRITE_STATUS_INVALIDATED;
+ } else if (cache->max_offset > original_max_offset) {
+ status = CONSUMER_METADATA_CACHE_WRITE_STATUS_APPENDED_CONTENT;
+ } else {
+ status = CONSUMER_METADATA_CACHE_WRITE_STATUS_NO_CHANGE;
+ assert(cache->max_offset == original_max_offset);
}
end:
- return ret;
+ return status;
}
/*