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;
}
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
* chunk can be used safely.
*/
if ((relay_stream->ongoing_rotation.is_set ||
- relay_session->ongoing_rotation) &&
+ session_has_ongoing_rotation(relay_session)) &&
relay_stream->trace_chunk) {
viewer_stream_trace_chunk = lttng_trace_chunk_copy(
relay_stream->trace_chunk);
goto error_unlock;
}
} else {
- const bool reference_acquired = lttng_trace_chunk_get(
- viewer_session->current_trace_chunk);
+ /*
+ * 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;
+ }
+ }
- assert(reference_acquired);
- viewer_stream_trace_chunk =
- viewer_session->current_trace_chunk;
+ if (relay_stream->trace_chunk) {
+ /*
+ * If the corresponding relay
+ * stream's trace chunk is set,
+ * the viewer stream will be
+ * created under it.
+ *
+ * Note that a relay stream can
+ * have a NULL output trace
+ * chunk (for instance, after a
+ * clear against a stopped
+ * session).
+ */
+ const bool reference_acquired = lttng_trace_chunk_get(
+ viewer_session->current_trace_chunk);
+
+ assert(reference_acquired);
+ viewer_stream_trace_chunk =
+ viewer_session->current_trace_chunk;
+ }
}
viewer_stream = viewer_stream_create(
error_unlock:
rcu_read_unlock();
-error:
+
if (relay_stream) {
pthread_mutex_unlock(&relay_stream->lock);
stream_put(relay_stream);
/* 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;
goto send_reply;
}
+ /*
+ * For any new stream, create it with LTTNG_VIEWER_SEEK_BEGINNING since
+ * that at this point the client is already attached to the session.Aany
+ * initial stream will have been created with the seek type at attach
+ * time (for now most readers use the LTTNG_VIEWER_SEEK_LAST on attach).
+ * Otherwise any event happening in a new stream between the attach and
+ * a call to viewer_get_new_streams will be "lost" (never received) from
+ * the viewer's point of view.
+ */
pthread_mutex_lock(&session->lock);
+ /*
+ * If a session rotation is ongoing, do not attempt to open any
+ * stream, because the chunk can be in an intermediate state
+ * due to directory renaming.
+ */
+ if (session_has_ongoing_rotation(session)) {
+ DBG("Relay session %" PRIu64 " rotation ongoing", session_id);
+ response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_NO_NEW);
+ goto send_reply_unlock;
+ }
ret = make_viewer_streams(session,
conn->viewer_session,
- LTTNG_VIEWER_SEEK_LAST, &nb_total, &nb_unsent,
+ LTTNG_VIEWER_SEEK_BEGINNING, &nb_total, &nb_unsent,
&nb_created, &closed);
if (ret < 0) {
- goto error_unlock_session;
+ /*
+ * This is caused by an internal error; propagate the negative
+ * 'ret' to close the connection.
+ */
+ response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_ERR);
+ goto send_reply;
}
send_streams = 1;
response.status = htobe32(LTTNG_VIEWER_NEW_STREAMS_OK);
}
error:
return ret;
-error_unlock_session:
- pthread_mutex_unlock(&session->lock);
- session_put(session);
- return ret;
}
/*
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);
goto send_reply;
}
+ /*
+ * If a session rotation is ongoing, do not attempt to open any
+ * stream, because the chunk can be in an intermediate state
+ * due to directory renaming.
+ */
+ if (session_has_ongoing_rotation(session)) {
+ DBG("Relay session %" PRIu64 " rotation ongoing", session_id);
+ send_streams = 0;
+ goto send_reply;
+ }
+
ret = make_viewer_streams(session,
conn->viewer_session, seek_type,
&nb_streams, NULL, NULL, &closed);
/*
* 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,
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.
*
metadata_viewer_stream =
ctf_trace_get_viewer_metadata_stream(ctf_trace);
+ /*
+ * Hold the session lock to protect against concurrent changes
+ * to the chunk files (e.g. rename done by clear), which are
+ * protected by the session ongoing rotation state. Those are
+ * synchronized with the session lock.
+ */
+ pthread_mutex_lock(&rstream->trace->session->lock);
pthread_mutex_lock(&rstream->lock);
/*
goto send_reply;
}
- if (rstream->trace->session->ongoing_rotation) {
+ if (session_has_ongoing_rotation(rstream->trace->session)) {
/* Rotation is ongoing, try again later. */
viewer_index.status = htobe32(LTTNG_VIEWER_INDEX_RETRY);
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");
goto send_reply;
}
}
- if (conn->viewer_session->current_trace_chunk !=
- vstream->stream_file.trace_chunk) {
- bool acquired_reference;
- DBG("Viewer session and viewer stream chunk differ: "
+ /*
+ * 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 (!lttng_trace_chunk_ids_equal(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 IDs 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);
send_reply:
if (rstream) {
pthread_mutex_unlock(&rstream->lock);
+ pthread_mutex_unlock(&rstream->trace->session->lock);
}
if (metadata_viewer_stream) {
error_put:
pthread_mutex_unlock(&rstream->lock);
+ pthread_mutex_unlock(&rstream->trace->session->lock);
if (metadata_viewer_stream) {
viewer_stream_put(metadata_viewer_stream);
}
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:
* an error.
*/
if (vstream->metadata_sent > 0) {
- vstream->stream->no_new_metadata_notified = true;
- if (vstream->stream->closed) {
+ if (vstream->stream->closed && vstream->stream->no_new_metadata_notified) {
/* Release ownership for the viewer metadata stream. */
viewer_stream_put(vstream);
}
+ vstream->stream->no_new_metadata_notified = true;
}
goto send_reply;
}
}
}
- if (conn->viewer_session->current_trace_chunk !=
- vstream->stream_file.trace_chunk) {
+ if (conn->viewer_session->current_trace_chunk &&
+ !lttng_trace_chunk_ids_equal(conn->viewer_session->current_trace_chunk,
+ vstream->stream_file.trace_chunk)) {
bool acquired_reference;
DBG("Viewer session and viewer stream chunk differ: "
len = vstream->stream->metadata_received - vstream->metadata_sent;
- /*
- * Either this is the first time the metadata file is read, or a
- * rotation of the corresponding relay stream has occured.
- */
- if (!vstream->stream_file.handle && len > 0) {
+ if (!vstream->stream_file.trace_chunk) {
+ reply.status = htobe32(LTTNG_VIEWER_NO_NEW_METADATA);
+ len = 0;
+ goto send_reply;
+ } else if (vstream->stream_file.trace_chunk &&
+ !vstream->stream_file.handle && len > 0) {
+ /*
+ * Either this is the first time the metadata file is read, or a
+ * rotation of the corresponding relay stream has occurred.
+ */
struct fs_handle *fs_handle;
char file_path[LTTNG_PATH_MAX];
enum lttng_trace_chunk_status status;
projects / lttng-tools.git / blobdiff