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 "ctf-trace.hpp"
12 #include "lttng-relayd.hpp"
13 #include "session.hpp"
15 #include "viewer-session.hpp"
16 #include "viewer-stream.hpp"
18 #include <common/common.hpp>
19 #include <common/urcu.hpp>
21 #include <urcu/rculist.h>
23 struct relay_viewer_session
*viewer_session_create()
25 struct relay_viewer_session
*vsession
;
27 vsession
= zmalloc
<relay_viewer_session
>();
31 CDS_INIT_LIST_HEAD(&vsession
->session_list
);
36 int viewer_session_set_trace_chunk_copy(struct relay_viewer_session
*vsession
,
37 struct lttng_trace_chunk
*relay_session_trace_chunk
)
40 struct lttng_trace_chunk
*viewer_chunk
;
42 lttng_trace_chunk_put(vsession
->current_trace_chunk
);
43 vsession
->current_trace_chunk
= nullptr;
45 DBG("Copying relay session's current trace chunk to the viewer session");
46 if (!relay_session_trace_chunk
) {
50 viewer_chunk
= lttng_trace_chunk_copy(relay_session_trace_chunk
);
52 ERR("Failed to create a viewer trace chunk from the relay session's current chunk");
57 vsession
->current_trace_chunk
= viewer_chunk
;
62 /* The existence of session must be guaranteed by the caller. */
63 enum lttng_viewer_attach_return_code
viewer_session_attach(struct relay_viewer_session
*vsession
,
64 struct relay_session
*session
)
66 enum lttng_viewer_attach_return_code viewer_attach_status
= 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
, session
->current_trace_chunk
);
85 * The live protocol does not define a generic error
86 * value for the "attach" command. The "unknown"
87 * status is used so that the viewer may handle this
88 * failure as if the session didn't exist anymore.
90 DBG("Failed to create a viewer trace chunk from the current trace chunk of session \"%s\", returning LTTNG_VIEWER_ATTACH_UNK",
91 session
->session_name
);
92 viewer_attach_status
= LTTNG_VIEWER_ATTACH_UNK
;
96 if (viewer_attach_status
== LTTNG_VIEWER_ATTACH_OK
) {
97 pthread_mutex_lock(&vsession
->session_list_lock
);
98 /* Ownership is transfered to the list. */
99 cds_list_add_rcu(&session
->viewer_session_node
, &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.
154 lttng::urcu::read_lock_guard read_guard
;
156 cds_lfht_for_each_entry (
157 viewer_streams_ht
->ht
, &iter
.iter
, vstream
, stream_n
.node
) {
158 if (!viewer_stream_get(vstream
)) {
161 if (vstream
->stream
->trace
->session
!= session
) {
162 viewer_stream_put(vstream
);
165 /* Put local reference. */
166 viewer_stream_put(vstream
);
168 * We have reached one of the viewer stream's lifetime
169 * end condition. This "put" will cause the proper
170 * teardown of the viewer stream.
172 viewer_stream_put(vstream
);
176 lttng_trace_chunk_put(vsession
->current_trace_chunk
);
177 vsession
->current_trace_chunk
= nullptr;
178 viewer_session_detach(vsession
, session
);
181 void viewer_session_close(struct relay_viewer_session
*vsession
)
183 struct relay_session
*session
;
186 lttng::urcu::read_lock_guard read_lock
;
188 cds_list_for_each_entry_rcu(session
, &vsession
->session_list
, viewer_session_node
)
190 viewer_session_close_one_session(vsession
, session
);
196 * Check if a connection is attached to a session.
197 * Return 1 if attached, 0 if not attached, a negative value on error.
199 int viewer_session_is_attached(struct relay_viewer_session
*vsession
, struct relay_session
*session
)
201 struct relay_session
*iter
;
204 pthread_mutex_lock(&session
->lock
);
208 if (!session
->viewer_attached
) {
213 lttng::urcu::read_lock_guard read_lock
;
214 cds_list_for_each_entry_rcu(iter
, &vsession
->session_list
, viewer_session_node
)
216 if (session
== iter
) {
224 pthread_mutex_unlock(&session
->lock
);