src/bin/lttng-relayd/stream.h

   1 #ifndef _STREAM_H
   2 #define _STREAM_H
   3
   4 /*
   5  * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
   6  *                      David Goulet <dgoulet@efficios.com>
   7  *               2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License, version 2 only, as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  16  * more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along with
  19  * this program; if not, write to the Free Software Foundation, Inc., 51
  20  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #include <limits.h>
  24 #include <inttypes.h>
  25 #include <pthread.h>
  26 #include <urcu/list.h>
  27
  28 #include <common/hashtable/hashtable.h>
  29
  30 #include "session.h"
  31 #include "stream-fd.h"
  32 #include "tracefile-array.h"
  33
  34 struct relay_stream_chunk_id {
  35         bool is_set;
  36         uint64_t value;
  37 };
  38
  39 /*
  40  * Represents a stream in the relay
  41  */
  42 struct relay_stream {
  43         uint64_t stream_handle;
  44
  45         struct urcu_ref ref;
  46         /* Back reference to trace. Protected by refcount on trace object. */
  47         struct ctf_trace *trace;
  48
  49         /*
  50          * To protect from concurrent read/update. The viewer stream
  51          * lock nests inside the stream lock. The stream lock nests
  52          * inside the ctf_trace lock.
  53          */
  54         pthread_mutex_t lock;
  55         /* previous data sequence number written to disk. */
  56         uint64_t prev_data_seq;
  57         /* previous index sequence number written to disk. */
  58         uint64_t prev_index_seq;
  59         /* seq num to encounter before closing. */
  60         uint64_t last_net_seq_num;
  61
  62         /* FD on which to write the stream data. */
  63         struct stream_fd *stream_fd;
  64         /* index file on which to write the index data. */
  65         struct lttng_index_file *index_file;
  66
  67         char *path_name;
  68         /*
  69          * prev_path_name is only used for session rotation support.
  70          * It is essentially used to work around the fact that index
  71          * files are always created from the 'data' connection.
  72          *
  73          * Hence, it is possible to receive a ROTATE_STREAM command
  74          * which affects the stream's path_name before the creation of
  75          * an index file. In this situation, the index file of the
  76          * 'previous' chunk would be created in the new destination folder.
  77          *
  78          * It would then be unlinked when the actual index of the new chunk
  79          * is created.
  80          */
  81         char *prev_path_name;
  82         char *channel_name;
  83
  84         /* On-disk circular buffer of tracefiles. */
  85         uint64_t tracefile_size;
  86         uint64_t tracefile_size_current;
  87         uint64_t tracefile_count;
  88
  89         /*
  90          * Position in the tracefile where we have the full index also on disk.
  91          */
  92         uint64_t pos_after_last_complete_data_index;
  93
  94         /*
  95          * Counts the number of received indexes. The "tag" associated
  96          * with an index is taken before incrementing this seqcount.
  97          * Therefore, the sequence tag associated with the last index
  98          * received is always index_received_seqcount - 1.
  99          */
 100         uint64_t index_received_seqcount;
 101
 102         /*
 103          * Tracefile array is an index of the stream trace files,
 104          * indexed by position. It allows keeping track of the oldest
 105          * available indexes when overwriting trace files in tracefile
 106          * rotation.
 107          */
 108         struct tracefile_array *tfa;
 109
 110         bool closed;            /* Stream is closed. */
 111         bool close_requested;   /* Close command has been received. */
 112
 113         /*
 114          * Counts number of indexes in indexes_ht. Redundant info.
 115          * Protected by stream lock.
 116          */
 117         int indexes_in_flight;
 118         struct lttng_ht *indexes_ht;
 119
 120         /*
 121          * If the stream is inactive, this field is updated with the
 122          * live beacon timestamp end, when it is active, this
 123          * field == -1ULL.
 124          */
 125         uint64_t beacon_ts_end;
 126
 127         /* CTF stream ID, -1ULL when unset (first packet not received yet). */
 128         uint64_t ctf_stream_id;
 129
 130         /* Indicate if the stream was initialized for a data pending command. */
 131         bool data_pending_check_done;
 132
 133         /* Is this stream a metadata stream ? */
 134         int32_t is_metadata;
 135         /* Amount of metadata received (bytes). */
 136         uint64_t metadata_received;
 137
 138         /*
 139          * Member of the stream list in struct ctf_trace.
 140          * Updates are protected by the stream_list_lock.
 141          * Traversals are protected by RCU.
 142          */
 143         struct cds_list_head stream_node;
 144         /*
 145          * Temporary list belonging to the connection until all streams
 146          * are received for that connection.
 147          * Member of the stream recv list in the connection.
 148          * Updates are protected by the stream_recv_list_lock.
 149          * Traversals are protected by RCU.
 150          */
 151         bool in_recv_list;
 152         struct cds_list_head recv_node;
 153         bool published; /* Protected by session lock. */
 154         /*
 155          * Node of stream within global stream hash table.
 156          */
 157         struct lttng_ht_node_u64 node;
 158         bool in_stream_ht;              /* is stream in stream hash table. */
 159         struct rcu_head rcu_node;       /* For call_rcu teardown. */
 160         /*
 161          * When we have written the data and index corresponding to this
 162          * seq_num, rotate the tracefile (session rotation). The path_name is
 163          * already up-to-date.
 164          * This is set to -1ULL when no rotation is pending.
 165          *
 166          * Always access with stream lock held.
 167          */
 168         uint64_t rotate_at_seq_num;
 169         /*
 170          * This is the id of the chunk where we are writing to if no rotation is
 171          * pending (rotate_at_seq_num == -1ULL). If a rotation is pending, this
 172          * is the chunk_id we will have after the rotation. It must be updated
 173          * atomically with rotate_at_seq_num.
 174          *
 175          * Always access with stream lock held.
 176          *
 177          * This attribute is not set if the stream is created by a pre-2.11
 178          * consumer.
 179          */
 180         struct relay_stream_chunk_id current_chunk_id;
 181 };
 182
 183 struct relay_stream *stream_create(struct ctf_trace *trace,
 184         uint64_t stream_handle, char *path_name,
 185         char *channel_name, uint64_t tracefile_size,
 186         uint64_t tracefile_count, const struct relay_stream_chunk_id *chunk_id);
 187
 188 struct relay_stream *stream_get_by_id(uint64_t stream_id);
 189 bool stream_get(struct relay_stream *stream);
 190 void stream_put(struct relay_stream *stream);
 191 void try_stream_close(struct relay_stream *stream);
 192 void stream_publish(struct relay_stream *stream);
 193 void print_relay_streams(void);
 194
 195 #endif /* _STREAM_H */