2 * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
3 * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
4 * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 * SPDX-License-Identifier: GPL-2.0-only
11 #include <common/common.h>
12 #include <urcu/rculist.h>
14 #include "lttng-relayd.h"
15 #include "ctf-trace.h"
17 #include "viewer-session.h"
18 #include "viewer-stream.h"
21 struct relay_viewer_session
*viewer_session_create(void)
23 struct relay_viewer_session
*vsession
;
25 vsession
= zmalloc(sizeof(*vsession
));
29 CDS_INIT_LIST_HEAD(&vsession
->session_list
);
34 int viewer_session_set_trace_chunk_copy(struct relay_viewer_session
*vsession
,
35 struct lttng_trace_chunk
*relay_session_trace_chunk
)
38 struct lttng_trace_chunk
*viewer_chunk
;
40 assert(relay_session_trace_chunk
);
41 assert(!vsession
->current_trace_chunk
);
43 DBG("Copying relay session's current trace chunk to the viewer session");
44 viewer_chunk
= lttng_trace_chunk_copy(relay_session_trace_chunk
);
46 ERR("Failed to create a viewer trace chunk from the relay session's current chunk");
51 vsession
->current_trace_chunk
= viewer_chunk
;
56 /* The existence of session must be guaranteed by the caller. */
57 enum lttng_viewer_attach_return_code
viewer_session_attach(
58 struct relay_viewer_session
*vsession
,
59 struct relay_session
*session
)
61 enum lttng_viewer_attach_return_code viewer_attach_status
=
62 LTTNG_VIEWER_ATTACH_OK
;
64 ASSERT_LOCKED(session
->lock
);
66 /* Will not fail, as per the ownership guarantee. */
67 if (!session_get(session
)) {
68 viewer_attach_status
= LTTNG_VIEWER_ATTACH_UNK
;
71 if (session
->viewer_attached
) {
72 viewer_attach_status
= LTTNG_VIEWER_ATTACH_ALREADY
;
76 assert(session
->current_trace_chunk
);
77 assert(!vsession
->current_trace_chunk
);
78 session
->viewer_attached
= true;
80 ret
= viewer_session_set_trace_chunk_copy(vsession
,
81 session
->current_trace_chunk
);
84 * The live protocol does not define a generic error
85 * value for the "attach" command. The "unknown"
86 * status is used so that the viewer may handle this
87 * failure as if the session didn't exist anymore.
89 DBG("Failed to create a viewer trace chunk from the current trace chunk of session \"%s\", returning LTTNG_VIEWER_ATTACH_UNK",
90 session
->session_name
);
91 viewer_attach_status
= LTTNG_VIEWER_ATTACH_UNK
;
95 if (viewer_attach_status
== LTTNG_VIEWER_ATTACH_OK
) {
96 pthread_mutex_lock(&vsession
->session_list_lock
);
97 /* Ownership is transfered to the list. */
98 cds_list_add_rcu(&session
->viewer_session_node
,
99 &vsession
->session_list
);
100 pthread_mutex_unlock(&vsession
->session_list_lock
);
102 /* Put our local ref. */
103 session_put(session
);
106 return viewer_attach_status
;
109 /* The existence of session must be guaranteed by the caller. */
110 static int viewer_session_detach(struct relay_viewer_session
*vsession
,
111 struct relay_session
*session
)
115 pthread_mutex_lock(&session
->lock
);
116 if (!session
->viewer_attached
) {
119 session
->viewer_attached
= false;
123 pthread_mutex_lock(&vsession
->session_list_lock
);
124 cds_list_del_rcu(&session
->viewer_session_node
);
125 pthread_mutex_unlock(&vsession
->session_list_lock
);
126 /* Release reference held by the list. */
127 session_put(session
);
129 /* Safe since we know the session exists. */
130 pthread_mutex_unlock(&session
->lock
);
134 void viewer_session_destroy(struct relay_viewer_session
*vsession
)
136 lttng_trace_chunk_put(vsession
->current_trace_chunk
);
141 * Release ownership of all the streams of one session and detach the viewer.
143 void viewer_session_close_one_session(struct relay_viewer_session
*vsession
,
144 struct relay_session
*session
)
146 struct lttng_ht_iter iter
;
147 struct relay_viewer_stream
*vstream
;
150 * TODO: improvement: create more efficient list of
151 * vstream per session.
153 cds_lfht_for_each_entry(viewer_streams_ht
->ht
, &iter
.iter
,
154 vstream
, stream_n
.node
) {
155 if (!viewer_stream_get(vstream
)) {
158 if (vstream
->stream
->trace
->session
!= session
) {
159 viewer_stream_put(vstream
);
162 /* Put local reference. */
163 viewer_stream_put(vstream
);
165 * We have reached one of the viewer stream's lifetime
166 * end condition. This "put" will cause the proper
167 * teardown of the viewer stream.
169 viewer_stream_put(vstream
);
171 lttng_trace_chunk_put(vsession
->current_trace_chunk
);
172 vsession
->current_trace_chunk
= NULL
;
173 viewer_session_detach(vsession
, session
);
176 void viewer_session_close(struct relay_viewer_session
*vsession
)
178 struct relay_session
*session
;
181 cds_list_for_each_entry_rcu(session
,
182 &vsession
->session_list
, viewer_session_node
) {
183 viewer_session_close_one_session(vsession
, session
);
189 * Check if a connection is attached to a session.
190 * Return 1 if attached, 0 if not attached, a negative value on error.
192 int viewer_session_is_attached(struct relay_viewer_session
*vsession
,
193 struct relay_session
*session
)
195 struct relay_session
*iter
;
198 pthread_mutex_lock(&session
->lock
);
202 if (!session
->viewer_attached
) {
206 cds_list_for_each_entry_rcu(iter
,
207 &vsession
->session_list
,
208 viewer_session_node
) {
209 if (session
== iter
) {
217 pthread_mutex_unlock(&session
->lock
);