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         char *channel_name;
  69
  70         /* On-disk circular buffer of tracefiles. */
  71         uint64_t tracefile_size;
  72         uint64_t tracefile_size_current;
  73         uint64_t tracefile_count;
  74
  75         /*
  76          * Position in the tracefile where we have the full index also on disk.
  77          */
  78         uint64_t pos_after_last_complete_data_index;
  79
  80         /*
  81          * Counts the number of received indexes. The "tag" associated
  82          * with an index is taken before incrementing this seqcount.
  83          * Therefore, the sequence tag associated with the last index
  84          * received is always index_received_seqcount - 1.
  85          */
  86         uint64_t index_received_seqcount;
  87
  88         /*
  89          * Tracefile array is an index of the stream trace files,
  90          * indexed by position. It allows keeping track of the oldest
  91          * available indexes when overwriting trace files in tracefile
  92          * rotation.
  93          */
  94         struct tracefile_array *tfa;
  95
  96         bool closed;            /* Stream is closed. */
  97         bool close_requested;   /* Close command has been received. */
  98
  99         /*
 100          * Counts number of indexes in indexes_ht. Redundant info.
 101          * Protected by stream lock.
 102          */
 103         int indexes_in_flight;
 104         struct lttng_ht *indexes_ht;
 105
 106         /*
 107          * If the stream is inactive, this field is updated with the
 108          * live beacon timestamp end, when it is active, this
 109          * field == -1ULL.
 110          */
 111         uint64_t beacon_ts_end;
 112
 113         /* CTF stream ID, -1ULL when unset (first packet not received yet). */
 114         uint64_t ctf_stream_id;
 115
 116         /* Indicate if the stream was initialized for a data pending command. */
 117         bool data_pending_check_done;
 118
 119         /* Is this stream a metadata stream ? */
 120         int32_t is_metadata;
 121         /* Amount of metadata received (bytes). */
 122         uint64_t metadata_received;
 123
 124         /*
 125          * Member of the stream list in struct ctf_trace.
 126          * Updates are protected by the stream_list_lock.
 127          * Traversals are protected by RCU.
 128          */
 129         struct cds_list_head stream_node;
 130         /*
 131          * Temporary list belonging to the connection until all streams
 132          * are received for that connection.
 133          * Member of the stream recv list in the connection.
 134          * Updates are protected by the stream_recv_list_lock.
 135          * Traversals are protected by RCU.
 136          */
 137         bool in_recv_list;
 138         struct cds_list_head recv_node;
 139         bool published; /* Protected by session lock. */
 140         /*
 141          * Node of stream within global stream hash table.
 142          */
 143         struct lttng_ht_node_u64 node;
 144         bool in_stream_ht;              /* is stream in stream hash table. */
 145         struct rcu_head rcu_node;       /* For call_rcu teardown. */
 146         /*
 147          * When we have written the data and index corresponding to this
 148          * seq_num, rotate the tracefile (session rotation). The path_name is
 149          * already up-to-date.
 150          * This is set to -1ULL when no rotation is pending.
 151          *
 152          * Always access with stream lock held.
 153          */
 154         uint64_t rotate_at_seq_num;
 155         /*
 156          * This is the id of the chunk where we are writing to if no rotation is
 157          * pending (rotate_at_seq_num == -1ULL). If a rotation is pending, this
 158          * is the chunk_id we will have after the rotation. It must be updated
 159          * atomically with rotate_at_seq_num.
 160          *
 161          * Always access with stream lock held.
 162          *
 163          * This attribute is not set if the stream is created by a pre-2.11
 164          * consumer.
 165          */
 166         struct relay_stream_chunk_id current_chunk_id;
 167 };
 168
 169 struct relay_stream *stream_create(struct ctf_trace *trace,
 170         uint64_t stream_handle, char *path_name,
 171         char *channel_name, uint64_t tracefile_size,
 172         uint64_t tracefile_count, const struct relay_stream_chunk_id *chunk_id);
 173
 174 struct relay_stream *stream_get_by_id(uint64_t stream_id);
 175 bool stream_get(struct relay_stream *stream);
 176 void stream_put(struct relay_stream *stream);
 177 void try_stream_close(struct relay_stream *stream);
 178 void stream_publish(struct relay_stream *stream);
 179 void print_relay_streams(void);
 180
 181 #endif /* _STREAM_H */