X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-relayd%2Flive.c;h=5877467c0d5598f0cbdc7481f08c144a0b7580b1;hp=7d6dc1bc20a03a5af6cafe1e5ef170be1b7f5cb8;hb=80516611b6f19201b1e173fb448935aca7a9e668;hpb=9edaf114d28249f4740de16bc9f58c43cfe8042e diff --git a/src/bin/lttng-relayd/live.c b/src/bin/lttng-relayd/live.c index 7d6dc1bc2..5877467c0 100644 --- a/src/bin/lttng-relayd/live.c +++ b/src/bin/lttng-relayd/live.c @@ -284,13 +284,6 @@ static int make_viewer_streams(struct relay_session *relay_session, assert(relay_session); ASSERT_LOCKED(relay_session->lock); - if (!viewer_session->current_trace_chunk) { - ERR("Internal error: viewer session associated with session \"%s\" has a NULL trace chunk", - relay_session->session_name); - ret = -1; - goto error; - } - if (relay_session->connection_closed) { *closed = true; } @@ -361,7 +354,7 @@ static int make_viewer_streams(struct relay_session *relay_session, viewer_stream = viewer_stream_get_by_id( relay_stream->stream_handle); if (!viewer_stream) { - struct lttng_trace_chunk *viewer_stream_trace_chunk; + struct lttng_trace_chunk *viewer_stream_trace_chunk = NULL; /* * Save that we sent the metadata stream to the @@ -391,9 +384,26 @@ static int make_viewer_streams(struct relay_session *relay_session, goto error_unlock; } } else { - const bool reference_acquired = lttng_trace_chunk_get( - viewer_session->current_trace_chunk); + bool reference_acquired; + + /* + * Transition the viewer session into the newest trace chunk available. + */ + if (!lttng_trace_chunk_ids_equal(viewer_session->current_trace_chunk, + relay_stream->trace_chunk)) { + + ret = viewer_session_set_trace_chunk_copy( + viewer_session, + relay_stream->trace_chunk); + if (ret) { + ret = -1; + ctf_trace_put(ctf_trace); + goto error_unlock; + } + } + reference_acquired = lttng_trace_chunk_get( + viewer_session->current_trace_chunk); assert(reference_acquired); viewer_stream_trace_chunk = viewer_session->current_trace_chunk; @@ -460,7 +470,7 @@ static int make_viewer_streams(struct relay_session *relay_session, error_unlock: rcu_read_unlock(); -error: + if (relay_stream) { pthread_mutex_unlock(&relay_stream->lock); stream_put(relay_stream); @@ -1018,14 +1028,6 @@ int viewer_list_sessions(struct relay_connection *conn) /* Skip closed session */ goto next_session; } - if (!session->current_trace_chunk) { - /* - * Skip un-attachable session. It is either - * being destroyed or has not had a trace - * chunk created against it yet. - */ - goto next_session; - } if (count >= buf_count) { struct lttng_viewer_session *newbuf; @@ -1254,15 +1256,6 @@ int viewer_attach_session(struct relay_connection *conn) DBG("Attach session ID %" PRIu64 " received", session_id); pthread_mutex_lock(&session->lock); - if (!session->current_trace_chunk) { - /* - * Session is either being destroyed or it never had a trace - * chunk created against it. - */ - DBG("Session requested by live client has no current trace chunk, returning unknown session"); - response.status = htobe32(LTTNG_VIEWER_ATTACH_UNK); - goto send_reply; - } if (session->live_timer == 0) { DBG("Not live session"); response.status = htobe32(LTTNG_VIEWER_ATTACH_NOT_LIVE); @@ -1371,10 +1364,12 @@ static int try_open_index(struct relay_viewer_stream *vstream, /* * First time, we open the index file and at least one index is ready. */ - if (rstream->index_received_seqcount == 0) { + if (rstream->index_received_seqcount == 0 || + !vstream->stream_file.trace_chunk) { ret = -ENOENT; goto end; } + chunk_status = lttng_index_file_create_from_trace_chunk_read_only( vstream->stream_file.trace_chunk, rstream->path_name, rstream->channel_name, rstream->tracefile_size, @@ -1528,6 +1523,24 @@ index_ready: return 1; } +static +void viewer_stream_rotate_to_trace_chunk(struct relay_viewer_stream *vstream, + struct lttng_trace_chunk *new_trace_chunk) +{ + lttng_trace_chunk_put(vstream->stream_file.trace_chunk); + + if (new_trace_chunk) { + const bool acquired_reference = lttng_trace_chunk_get( + new_trace_chunk); + + assert(acquired_reference); + } + + vstream->stream_file.trace_chunk = new_trace_chunk; + viewer_stream_sync_tracefile_array_tail(vstream); + viewer_stream_close_files(vstream); +} + /* * Send the next index for a stream. * @@ -1596,7 +1609,10 @@ int viewer_get_next_index(struct relay_connection *conn) goto send_reply; } - if (rstream->trace_chunk && !lttng_trace_chunk_ids_equal( + /* + * Transition the viewer session into the newest trace chunk available. + */ + if (!lttng_trace_chunk_ids_equal( conn->viewer_session->current_trace_chunk, rstream->trace_chunk)) { DBG("Relay stream and viewer chunk ids differ"); @@ -1609,21 +1625,28 @@ int viewer_get_next_index(struct relay_connection *conn) goto send_reply; } } - if (conn->viewer_session->current_trace_chunk != - vstream->stream_file.trace_chunk) { - bool acquired_reference; + /* + * Transition the viewer stream into the latest trace chunk available. + * + * Note that the stream must _not_ rotate in one precise condition: + * the relay stream has rotated to a NULL trace chunk and the viewer + * stream is consuming the trace chunk that was active just before + * that rotation to NULL. + * + * This allows clients to consume all the packets of a trace chunk + * after a session's destruction. + */ + if (conn->viewer_session->current_trace_chunk != vstream->stream_file.trace_chunk && + !(rstream->completed_rotation_count == vstream->last_seen_rotation_count + 1 && !rstream->trace_chunk)) { DBG("Viewer session and viewer stream chunk differ: " "vsession chunk %p vstream chunk %p", conn->viewer_session->current_trace_chunk, vstream->stream_file.trace_chunk); - lttng_trace_chunk_put(vstream->stream_file.trace_chunk); - acquired_reference = lttng_trace_chunk_get(conn->viewer_session->current_trace_chunk); - assert(acquired_reference); - vstream->stream_file.trace_chunk = - conn->viewer_session->current_trace_chunk; - viewer_stream_sync_tracefile_array_tail(vstream); - viewer_stream_close_files(vstream); + viewer_stream_rotate_to_trace_chunk(vstream, + conn->viewer_session->current_trace_chunk); + vstream->last_seen_rotation_count = + rstream->completed_rotation_count; } ret = check_index_status(vstream, rstream, ctf_trace, &viewer_index); @@ -1854,6 +1877,8 @@ int viewer_get_packet(struct relay_connection *conn) goto send_reply; error: + /* No payload to send on error. */ + reply_size = sizeof(reply_header); reply_header.status = htobe32(LTTNG_VIEWER_GET_PACKET_ERR); send_reply: