X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-relayd%2Fviewer-session.c;h=0b77fd144c6a58e407edc7118a450eb8a6cf7848;hp=657d3fc36a0892a4bbfa4268a58790539799dc9e;hb=ad8bec244fdbb0e7705fd1865ae71f36f06d2b94;hpb=7591bab11eceedc6a0d1e02fd6f85592267a63b5 diff --git a/src/bin/lttng-relayd/viewer-session.c b/src/bin/lttng-relayd/viewer-session.c index 657d3fc36..0b77fd144 100644 --- a/src/bin/lttng-relayd/viewer-session.c +++ b/src/bin/lttng-relayd/viewer-session.c @@ -1,23 +1,12 @@ /* - * Copyright (C) 2013 - Julien Desfossez - * David Goulet - * 2015 - Mathieu Desnoyers + * Copyright (C) 2013 Julien Desfossez + * Copyright (C) 2013 David Goulet + * Copyright (C) 2015 Mathieu Desnoyers * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License, version 2 only, as - * published by the Free Software Foundation. + * SPDX-License-Identifier: GPL-2.0-only * - * This program is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along with - * this program; if not, write to the Free Software Foundation, Inc., 51 - * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ -#define _GNU_SOURCE #define _LGPL_SOURCE #include #include @@ -42,25 +31,69 @@ end: return vsession; } +int viewer_session_set_trace_chunk_copy(struct relay_viewer_session *vsession, + struct lttng_trace_chunk *relay_session_trace_chunk) +{ + int ret = 0; + struct lttng_trace_chunk *viewer_chunk; + + assert(relay_session_trace_chunk); + lttng_trace_chunk_put(vsession->current_trace_chunk); + vsession->current_trace_chunk = NULL; + + DBG("Copying relay session's current trace chunk to the viewer session"); + viewer_chunk = lttng_trace_chunk_copy(relay_session_trace_chunk); + if (!viewer_chunk) { + ERR("Failed to create a viewer trace chunk from the relay session's current chunk"); + ret = -1; + goto end; + } + + vsession->current_trace_chunk = viewer_chunk; +end: + return ret; +} + /* The existence of session must be guaranteed by the caller. */ -int viewer_session_attach(struct relay_viewer_session *vsession, +enum lttng_viewer_attach_return_code viewer_session_attach( + struct relay_viewer_session *vsession, struct relay_session *session) { - int ret = 0; + enum lttng_viewer_attach_return_code viewer_attach_status = + LTTNG_VIEWER_ATTACH_OK; + + ASSERT_LOCKED(session->lock); /* Will not fail, as per the ownership guarantee. */ if (!session_get(session)) { - ret = -1; + viewer_attach_status = LTTNG_VIEWER_ATTACH_UNK; goto end; } - pthread_mutex_lock(&session->lock); if (session->viewer_attached) { - ret = -1; + viewer_attach_status = LTTNG_VIEWER_ATTACH_ALREADY; } else { + int ret; + + assert(session->current_trace_chunk); + assert(!vsession->current_trace_chunk); session->viewer_attached = true; + + ret = viewer_session_set_trace_chunk_copy(vsession, + session->current_trace_chunk); + if (ret) { + /* + * The live protocol does not define a generic error + * value for the "attach" command. The "unknown" + * status is used so that the viewer may handle this + * failure as if the session didn't exist anymore. + */ + DBG("Failed to create a viewer trace chunk from the current trace chunk of session \"%s\", returning LTTNG_VIEWER_ATTACH_UNK", + session->session_name); + viewer_attach_status = LTTNG_VIEWER_ATTACH_UNK; + } } - if (!ret) { + if (viewer_attach_status == LTTNG_VIEWER_ATTACH_OK) { pthread_mutex_lock(&vsession->session_list_lock); /* Ownership is transfered to the list. */ cds_list_add_rcu(&session->viewer_session_node, @@ -70,10 +103,8 @@ int viewer_session_attach(struct relay_viewer_session *vsession, /* Put our local ref. */ session_put(session); } - /* Safe since we know the session exists. */ - pthread_mutex_unlock(&session->lock); end: - return ret; + return viewer_attach_status; } /* The existence of session must be guaranteed by the caller. */ @@ -103,9 +134,46 @@ static int viewer_session_detach(struct relay_viewer_session *vsession, void viewer_session_destroy(struct relay_viewer_session *vsession) { + lttng_trace_chunk_put(vsession->current_trace_chunk); 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); + } + lttng_trace_chunk_put(vsession->current_trace_chunk); + vsession->current_trace_chunk = NULL; + viewer_session_detach(vsession, session); +} + void viewer_session_close(struct relay_viewer_session *vsession) { struct relay_session *session; @@ -113,32 +181,7 @@ 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(); }