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 /*
  35  * Represents a stream in the relay
  36  */
  37 struct relay_stream {
  38         uint64_t stream_handle;
  39
  40         struct urcu_ref ref;
  41         /* Back reference to trace. Protected by refcount on trace object. */
  42         struct ctf_trace *trace;
  43
  44         /*
  45          * To protect from concurrent read/update. The viewer stream
  46          * lock nests inside the stream lock. The stream lock nests
  47          * inside the ctf_trace lock.
  48          */
  49         pthread_mutex_t lock;
  50         uint64_t prev_seq;              /* previous data sequence number encountered. */
  51         uint64_t last_net_seq_num;      /* seq num to encounter before closing. */
  52
  53         /* FD on which to write the stream data. */
  54         struct stream_fd *stream_fd;
  55         /* index file on which to write the index data. */
  56         struct lttng_index_file *index_file;
  57
  58         char *path_name;
  59         char *channel_name;
  60
  61         /* On-disk circular buffer of tracefiles. */
  62         uint64_t tracefile_size;
  63         uint64_t tracefile_size_current;
  64         uint64_t tracefile_count;
  65
  66         /*
  67          * Position in the tracefile where we have the full index also on disk.
  68          */
  69         uint64_t pos_after_last_complete_data_index;
  70
  71         /*
  72          * Counts the number of received indexes. The "tag" associated
  73          * with an index is taken before incrementing this seqcount.
  74          * Therefore, the sequence tag associated with the last index
  75          * received is always index_received_seqcount - 1.
  76          */
  77         uint64_t index_received_seqcount;
  78
  79         /*
  80          * Tracefile array is an index of the stream trace files,
  81          * indexed by position. It allows keeping track of the oldest
  82          * available indexes when overwriting trace files in tracefile
  83          * rotation.
  84          */
  85         struct tracefile_array *tfa;
  86
  87         bool closed;            /* Stream is closed. */
  88         bool close_requested;   /* Close command has been received. */
  89
  90         /*
  91          * Counts number of indexes in indexes_ht. Redundant info.
  92          * Protected by stream lock.
  93          */
  94         int indexes_in_flight;
  95         struct lttng_ht *indexes_ht;
  96
  97         /*
  98          * If the stream is inactive, this field is updated with the
  99          * live beacon timestamp end, when it is active, this
 100          * field == -1ULL.
 101          */
 102         uint64_t beacon_ts_end;
 103
 104         /* CTF stream ID, -1ULL when unset (first packet not received yet). */
 105         uint64_t ctf_stream_id;
 106
 107         /* Indicate if the stream was initialized for a data pending command. */
 108         bool data_pending_check_done;
 109
 110         /* Is this stream a metadata stream ? */
 111         int32_t is_metadata;
 112         /* Amount of metadata received (bytes). */
 113         uint64_t metadata_received;
 114
 115         /*
 116          * Member of the stream list in struct ctf_trace.
 117          * Updates are protected by the stream_list_lock.
 118          * Traversals are protected by RCU.
 119          */
 120         struct cds_list_head stream_node;
 121         /*
 122          * Temporary list belonging to the connection until all streams
 123          * are received for that connection.
 124          * Member of the stream recv list in the connection.
 125          * Updates are protected by the stream_recv_list_lock.
 126          * Traversals are protected by RCU.
 127          */
 128         bool in_recv_list;
 129         struct cds_list_head recv_node;
 130         bool published; /* Protected by session lock. */
 131         /*
 132          * Node of stream within global stream hash table.
 133          */
 134         struct lttng_ht_node_u64 node;
 135         bool in_stream_ht;              /* is stream in stream hash table. */
 136         struct rcu_head rcu_node;       /* For call_rcu teardown. */
 137         /*
 138          * When we have written the data and index corresponding to this
 139          * seq_num, rotate the tracefile (session rotation). The path_name is
 140          * already up-to-date.
 141          * This is set to -1ULL when no rotation is pending.
 142          *
 143          * Always access with stream lock held.
 144          */
 145         uint64_t rotate_at_seq_num;
 146         /*
 147          * This is the id of the chunk where we are writing to if no rotation is
 148          * pending (rotate_at_seq_num == -1ULL). If a rotation is pending, this
 149          * is the chunk_id we will have after the rotation. It must be updated
 150          * atomically with rotate_at_seq_num.
 151          *
 152          * Always access with stream lock held.
 153          */
 154         uint64_t chunk_id;
 155 };
 156
 157 struct relay_stream *stream_create(struct ctf_trace *trace,
 158         uint64_t stream_handle, char *path_name,
 159         char *channel_name, uint64_t tracefile_size,
 160         uint64_t tracefile_count);
 161
 162 struct relay_stream *stream_get_by_id(uint64_t stream_id);
 163 bool stream_get(struct relay_stream *stream);
 164 void stream_put(struct relay_stream *stream);
 165 void try_stream_close(struct relay_stream *stream);
 166 void stream_publish(struct relay_stream *stream);
 167 void print_relay_streams(void);
 168
 169 #endif /* _STREAM_H */