From d62023be5fccac24ad404aff2915c1888c22755c Mon Sep 17 00:00:00 2001 From: Julien Desfossez Date: Mon, 7 Mar 2016 12:46:50 -0500 Subject: [PATCH] Live: command to detach a viewer session MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The LTTNG_VIEWER_DETACH_SESSION command allows the viewer to detach from a session it is currently attached to without requiring it to close the network connection. Fixes: #853 Signed-off-by: Julien Desfossez Signed-off-by: Jérémie Galarneau --- src/bin/lttng-relayd/live.c | 75 +++++++++++++++++++++++++ src/bin/lttng-relayd/lttng-viewer-abi.h | 19 +++++++ src/bin/lttng-relayd/viewer-session.c | 62 +++++++++++--------- src/bin/lttng-relayd/viewer-session.h | 2 + 4 files changed, 132 insertions(+), 26 deletions(-) diff --git a/src/bin/lttng-relayd/live.c b/src/bin/lttng-relayd/live.c index 0cf266516..a9f4f648b 100644 --- a/src/bin/lttng-relayd/live.c +++ b/src/bin/lttng-relayd/live.c @@ -1734,6 +1734,78 @@ end: return ret; } +/* + * Detach a viewer session. + * + * Return 0 on success or else a negative value. + */ +static +int viewer_detach_session(struct relay_connection *conn) +{ + int ret; + struct lttng_viewer_detach_session_response response; + struct lttng_viewer_detach_session_request request; + struct relay_session *session = NULL; + uint64_t viewer_session_to_close; + + DBG("Viewer detach session received"); + + assert(conn); + + health_code_update(); + + /* Receive the request from the connected client. */ + ret = recv_request(conn->sock, &request, sizeof(request)); + if (ret < 0) { + goto end; + } + viewer_session_to_close = be64toh(request.session_id); + + if (!conn->viewer_session) { + DBG("Client trying to detach before creating a live viewer session"); + response.status = htobe32(LTTNG_VIEWER_DETACH_SESSION_ERR); + goto send_reply; + } + + health_code_update(); + + memset(&response, 0, sizeof(response)); + DBG("Detaching from session ID %" PRIu64, viewer_session_to_close); + + session = session_get_by_id(be64toh(request.session_id)); + if (!session) { + DBG("Relay session %" PRIu64 " not found", + be64toh(request.session_id)); + response.status = htobe32(LTTNG_VIEWER_DETACH_SESSION_UNK); + goto send_reply; + } + + ret = viewer_session_is_attached(conn->viewer_session, session); + if (ret != 1) { + DBG("Not attached to this session"); + response.status = htobe32(LTTNG_VIEWER_DETACH_SESSION_ERR); + goto send_reply_put; + } + + viewer_session_close_one_session(conn->viewer_session, session); + response.status = htobe32(LTTNG_VIEWER_DETACH_SESSION_OK); + DBG("Session %" PRIu64 " detached.", viewer_session_to_close); + +send_reply_put: + session_put(session); + +send_reply: + health_code_update(); + ret = send_response(conn->sock, &response, sizeof(response)); + if (ret < 0) { + goto end; + } + health_code_update(); + ret = 0; + +end: + return ret; +} /* * live_relay_unknown_command: send -1 if received unknown command @@ -1795,6 +1867,9 @@ int process_control(struct lttng_viewer_cmd *recv_hdr, case LTTNG_VIEWER_CREATE_SESSION: ret = viewer_create_session(conn); break; + case LTTNG_VIEWER_DETACH_SESSION: + ret = viewer_detach_session(conn); + break; default: ERR("Received unknown viewer command (%u)", be32toh(recv_hdr->cmd)); diff --git a/src/bin/lttng-relayd/lttng-viewer-abi.h b/src/bin/lttng-relayd/lttng-viewer-abi.h index f9bce98d0..35267ca3f 100644 --- a/src/bin/lttng-relayd/lttng-viewer-abi.h +++ b/src/bin/lttng-relayd/lttng-viewer-abi.h @@ -48,6 +48,7 @@ enum lttng_viewer_command { LTTNG_VIEWER_GET_METADATA = 6, LTTNG_VIEWER_GET_NEW_STREAMS = 7, LTTNG_VIEWER_CREATE_SESSION = 8, + LTTNG_VIEWER_DETACH_SESSION = 9, }; enum lttng_viewer_attach_return_code { @@ -105,6 +106,12 @@ enum lttng_viewer_create_session_return_code { LTTNG_VIEWER_CREATE_SESSION_ERR = 2, }; +enum lttng_viewer_detach_session_return_code { + LTTNG_VIEWER_DETACH_SESSION_OK = 1, + LTTNG_VIEWER_DETACH_SESSION_UNK = 2, + LTTNG_VIEWER_DETACH_SESSION_ERR = 3, +}; + struct lttng_viewer_session { uint64_t id; uint32_t live_timer; @@ -232,4 +239,16 @@ struct lttng_viewer_create_session_response { uint32_t status; } __attribute__((__packed__)); +/* + * LTTNG_VIEWER_DETACH_SESSION payload. + */ +struct lttng_viewer_detach_session_request { + uint64_t session_id; +} __attribute__((__packed__)); + +struct lttng_viewer_detach_session_response { + /* enum lttng_viewer_detach_session_return_code */ + uint32_t status; +} __attribute__((__packed__)); + #endif /* LTTNG_VIEWER_ABI_H */ diff --git a/src/bin/lttng-relayd/viewer-session.c b/src/bin/lttng-relayd/viewer-session.c index 6d74b3517..a4b859726 100644 --- a/src/bin/lttng-relayd/viewer-session.c +++ b/src/bin/lttng-relayd/viewer-session.c @@ -105,6 +105,41 @@ void viewer_session_destroy(struct relay_viewer_session *vsession) free(vsession); } +/* + * Release ownership of all the streams of one session and detach the viewer. + */ +void viewer_session_close_one_session(struct relay_viewer_session *vsession, + struct relay_session *session) +{ + struct lttng_ht_iter iter; + struct relay_viewer_stream *vstream; + + /* + * TODO: improvement: create more efficient list of + * vstream per session. + */ + cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, + vstream, stream_n.node) { + if (!viewer_stream_get(vstream)) { + continue; + } + if (vstream->stream->trace->session != session) { + viewer_stream_put(vstream); + continue; + } + /* Put local reference. */ + viewer_stream_put(vstream); + /* + * We have reached one of the viewer stream's lifetime + * end condition. This "put" will cause the proper + * teardown of the viewer stream. + */ + viewer_stream_put(vstream); + } + + viewer_session_detach(vsession, session); +} + void viewer_session_close(struct relay_viewer_session *vsession) { struct relay_session *session; @@ -112,32 +147,7 @@ void viewer_session_close(struct relay_viewer_session *vsession) rcu_read_lock(); cds_list_for_each_entry_rcu(session, &vsession->session_list, viewer_session_node) { - struct lttng_ht_iter iter; - struct relay_viewer_stream *vstream; - - /* - * TODO: improvement: create more efficient list of - * vstream per session. - */ - cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, - vstream, stream_n.node) { - if (!viewer_stream_get(vstream)) { - continue; - } - if (vstream->stream->trace->session != session) { - viewer_stream_put(vstream); - continue; - } - /* Put local reference. */ - viewer_stream_put(vstream); - /* - * We have reached one of the viewer stream's lifetime - * end condition. - */ - viewer_stream_put(vstream); - } - - viewer_session_detach(vsession, session); + viewer_session_close_one_session(vsession, session); } rcu_read_unlock(); } diff --git a/src/bin/lttng-relayd/viewer-session.h b/src/bin/lttng-relayd/viewer-session.h index 4013b3587..249a483d5 100644 --- a/src/bin/lttng-relayd/viewer-session.h +++ b/src/bin/lttng-relayd/viewer-session.h @@ -49,5 +49,7 @@ int viewer_session_attach(struct relay_viewer_session *vsession, struct relay_session *session); int viewer_session_is_attached(struct relay_viewer_session *vsession, struct relay_session *session); +void viewer_session_close_one_session(struct relay_viewer_session *vsession, + struct relay_session *session); #endif /* _VIEWER_SESSION_H */ -- 2.34.1