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 #include "index-file.h"
  34
  35 /*
  36  * Represents a stream in the relay
  37  */
  38 struct relay_stream {
  39         uint64_t stream_handle;
  40
  41         /*
  42          * reflock used to synchronize the closing of this stream.
  43          * stream reflock nests inside viewer stream reflock.
  44          * stream reflock nests inside index reflock.
  45          */
  46         pthread_mutex_t reflock;
  47         struct urcu_ref ref;
  48         /* Back reference to trace. Protected by refcount on trace object. */
  49         struct ctf_trace *trace;
  50
  51         /*
  52          * To protect from concurrent read/update. The viewer stream
  53          * lock nests inside the stream lock. The stream lock nests
  54          * inside the ctf_trace lock.
  55          */
  56         pthread_mutex_t lock;
  57         uint64_t prev_seq;              /* previous data sequence number encountered. */
  58         uint64_t last_net_seq_num;      /* seq num to encounter before closing. */
  59
  60         /* FD on which to write the stream data. */
  61         struct stream_fd *stream_fd;
  62         /* index file on which to write the index data. */
  63         struct relay_index_file *index_file;
  64
  65         char *path_name;
  66         char *channel_name;
  67
  68         /* On-disk circular buffer of tracefiles. */
  69         uint64_t tracefile_size;
  70         uint64_t tracefile_size_current;
  71         uint64_t tracefile_count;
  72
  73         /*
  74          * Counts the number of received indexes. The "tag" associated
  75          * with an index is taken before incrementing this seqcount.
  76          * Therefore, the sequence tag associated with the last index
  77          * received is always index_received_seqcount - 1.
  78          */
  79         uint64_t index_received_seqcount;
  80
  81         /*
  82          * Tracefile array is an index of the stream trace files,
  83          * indexed by position. It allows keeping track of the oldest
  84          * available indexes when overwriting trace files in tracefile
  85          * rotation.
  86          */
  87         struct tracefile_array *tfa;
  88
  89         bool closed;            /* Stream is closed. */
  90         bool close_requested;   /* Close command has been received. */
  91
  92         /*
  93          * Counts number of indexes in indexes_ht. Redundant info.
  94          * Protected by stream lock.
  95          */
  96         int indexes_in_flight;
  97         struct lttng_ht *indexes_ht;
  98
  99         /*
 100          * If the stream is inactive, this field is updated with the
 101          * live beacon timestamp end, when it is active, this
 102          * field == -1ULL.
 103          */
 104         uint64_t beacon_ts_end;
 105
 106         /* CTF stream ID, -1ULL when unset (first packet not received yet). */
 107         uint64_t ctf_stream_id;
 108
 109         /* Indicate if the stream was initialized for a data pending command. */
 110         bool data_pending_check_done;
 111
 112         /* Is this stream a metadata stream ? */
 113         int32_t is_metadata;
 114         /* Amount of metadata received (bytes). */
 115         uint64_t metadata_received;
 116
 117         /*
 118          * Member of the stream list in struct ctf_trace.
 119          * Updates are protected by the stream_list_lock.
 120          * Traversals are protected by RCU.
 121          */
 122         struct cds_list_head stream_node;
 123         /*
 124          * Temporary list belonging to the connection until all streams
 125          * are received for that connection.
 126          * Member of the stream recv list in the connection.
 127          * Updates are protected by the stream_recv_list_lock.
 128          * Traversals are protected by RCU.
 129          */
 130         bool in_recv_list;
 131         struct cds_list_head recv_node;
 132         bool published; /* Protected by session lock. */
 133         /*
 134          * Node of stream within global stream hash table.
 135          */
 136         struct lttng_ht_node_u64 node;
 137         bool in_stream_ht;              /* is stream in stream hash table. */
 138         struct rcu_head rcu_node;       /* For call_rcu teardown. */
 139 };
 140
 141 struct relay_stream *stream_create(struct ctf_trace *trace,
 142         uint64_t stream_handle, char *path_name,
 143         char *channel_name, uint64_t tracefile_size,
 144         uint64_t tracefile_count);
 145
 146 struct relay_stream *stream_get_by_id(uint64_t stream_id);
 147 bool stream_get(struct relay_stream *stream);
 148 void stream_put(struct relay_stream *stream);
 149 void try_stream_close(struct relay_stream *stream);
 150 void stream_publish(struct relay_stream *stream);
 151 void print_relay_streams(void);
 152
 153 #endif /* _STREAM_H */