src/common/consumer/consumer-metadata-cache.h

   1 /*
   2  * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
   3  * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
   4  *
   5  * SPDX-License-Identifier: GPL-2.0-only
   6  *
   7  */
   8
   9 #ifndef CONSUMER_METADATA_CACHE_H
  10 #define CONSUMER_METADATA_CACHE_H
  11
  12 #include <common/consumer/consumer.h>
  13
  14 struct consumer_metadata_cache {
  15         char *data;
  16         uint64_t cache_alloc_size;
  17         /*
  18          * Current version of the metadata cache.
  19          */
  20         uint64_t version;
  21         /*
  22          * The upper-limit of data written inside the buffer.
  23          *
  24          * With the total_bytes_written it allows us to keep track of when the
  25          * cache contains contiguous metadata ready to be sent to the RB.
  26          * All cached data is contiguous.
  27          */
  28         uint64_t max_offset;
  29         /*
  30          * Lock to update the metadata cache and push into the ring_buffer
  31          * (ustctl_write_metadata_to_channel).
  32          *
  33          * This is nested INSIDE the consumer_data lock.
  34          */
  35         pthread_mutex_t lock;
  36 };
  37
  38 int consumer_metadata_cache_write(struct lttng_consumer_channel *channel,
  39                 unsigned int offset, unsigned int len, uint64_t version,
  40                 char *data);
  41 int consumer_metadata_cache_allocate(struct lttng_consumer_channel *channel);
  42 void consumer_metadata_cache_destroy(struct lttng_consumer_channel *channel);
  43 int consumer_metadata_cache_flushed(struct lttng_consumer_channel *channel,
  44                 uint64_t offset, int timer);
  45 int consumer_metadata_wakeup_pipe(const struct lttng_consumer_channel *channel);
  46
  47 #endif /* CONSUMER_METADATA_CACHE_H */