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
= (relay_viewer_session
*) 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 lttng_trace_chunk_put(vsession
->current_trace_chunk
);
41 vsession
->current_trace_chunk
= NULL
;
43 DBG("Copying relay session's current trace chunk to the viewer session");
44 if (!relay_session_trace_chunk
) {
48 viewer_chunk
= lttng_trace_chunk_copy(relay_session_trace_chunk
);
50 ERR("Failed to create a viewer trace chunk from the relay session's current chunk");
55 vsession
->current_trace_chunk
= viewer_chunk
;
60 /* The existence of session must be guaranteed by the caller. */
61 enum lttng_viewer_attach_return_code
viewer_session_attach(
62 struct relay_viewer_session
*vsession
,
63 struct relay_session
*session
)
65 enum lttng_viewer_attach_return_code viewer_attach_status
=
66 LTTNG_VIEWER_ATTACH_OK
;
68 ASSERT_LOCKED(session
->lock
);
70 /* Will not fail, as per the ownership guarantee. */
71 if (!session_get(session
)) {
72 viewer_attach_status
= LTTNG_VIEWER_ATTACH_UNK
;
75 if (session
->viewer_attached
) {
76 viewer_attach_status
= LTTNG_VIEWER_ATTACH_ALREADY
;
80 session
->viewer_attached
= true;
82 ret
= viewer_session_set_trace_chunk_copy(vsession
,
83 session
->current_trace_chunk
);
86 * The live protocol does not define a generic error
87 * value for the "attach" command. The "unknown"
88 * status is used so that the viewer may handle this
89 * failure as if the session didn't exist anymore.
91 DBG("Failed to create a viewer trace chunk from the current trace chunk of session \"%s\", returning LTTNG_VIEWER_ATTACH_UNK",
92 session
->session_name
);
93 viewer_attach_status
= LTTNG_VIEWER_ATTACH_UNK
;
97 if (viewer_attach_status
== LTTNG_VIEWER_ATTACH_OK
) {
98 pthread_mutex_lock(&vsession
->session_list_lock
);
99 /* Ownership is transfered to the list. */
100 cds_list_add_rcu(&session
->viewer_session_node
,
101 &vsession
->session_list
);
102 pthread_mutex_unlock(&vsession
->session_list_lock
);
104 /* Put our local ref. */
105 session_put(session
);
108 return viewer_attach_status
;
111 /* The existence of session must be guaranteed by the caller. */
112 static int viewer_session_detach(struct relay_viewer_session
*vsession
,
113 struct relay_session
*session
)
117 pthread_mutex_lock(&session
->lock
);
118 if (!session
->viewer_attached
) {
121 session
->viewer_attached
= false;
125 pthread_mutex_lock(&vsession
->session_list_lock
);
126 cds_list_del_rcu(&session
->viewer_session_node
);
127 pthread_mutex_unlock(&vsession
->session_list_lock
);
128 /* Release reference held by the list. */
129 session_put(session
);
131 /* Safe since we know the session exists. */
132 pthread_mutex_unlock(&session
->lock
);
136 void viewer_session_destroy(struct relay_viewer_session
*vsession
)
138 lttng_trace_chunk_put(vsession
->current_trace_chunk
);
143 * Release ownership of all the streams of one session and detach the viewer.
145 void viewer_session_close_one_session(struct relay_viewer_session
*vsession
,
146 struct relay_session
*session
)
148 struct lttng_ht_iter iter
;
149 struct relay_viewer_stream
*vstream
;
152 * TODO: improvement: create more efficient list of
153 * vstream per session.
155 cds_lfht_for_each_entry(viewer_streams_ht
->ht
, &iter
.iter
,
156 vstream
, stream_n
.node
) {
157 if (!viewer_stream_get(vstream
)) {
160 if (vstream
->stream
->trace
->session
!= session
) {
161 viewer_stream_put(vstream
);
164 /* Put local reference. */
165 viewer_stream_put(vstream
);
167 * We have reached one of the viewer stream's lifetime
168 * end condition. This "put" will cause the proper
169 * teardown of the viewer stream.
171 viewer_stream_put(vstream
);
173 lttng_trace_chunk_put(vsession
->current_trace_chunk
);
174 vsession
->current_trace_chunk
= NULL
;
175 viewer_session_detach(vsession
, session
);
178 void viewer_session_close(struct relay_viewer_session
*vsession
)
180 struct relay_session
*session
;
183 cds_list_for_each_entry_rcu(session
,
184 &vsession
->session_list
, viewer_session_node
) {
185 viewer_session_close_one_session(vsession
, session
);
191 * Check if a connection is attached to a session.
192 * Return 1 if attached, 0 if not attached, a negative value on error.
194 int viewer_session_is_attached(struct relay_viewer_session
*vsession
,
195 struct relay_session
*session
)
197 struct relay_session
*iter
;
200 pthread_mutex_lock(&session
->lock
);
204 if (!session
->viewer_attached
) {
208 cds_list_for_each_entry_rcu(iter
,
209 &vsession
->session_list
,
210 viewer_session_node
) {
211 if (session
== iter
) {
219 pthread_mutex_unlock(&session
->lock
);