lib: rename transforming bt_X_borrow_Y() -> bt_X_as_Y()
[babeltrace.git] / lib / graph / connection.c
1 /*
2 * Copyright 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 *
4 * Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22 * SOFTWARE.
23 */
24
25 #define BT_LOG_TAG "CONNECTION"
26 #include <babeltrace/lib-logging-internal.h>
27
28 #include <babeltrace/graph/notification-iterator-internal.h>
29 #include <babeltrace/graph/component-internal.h>
30 #include <babeltrace/graph/connection-internal.h>
31 #include <babeltrace/graph/graph-internal.h>
32 #include <babeltrace/graph/port-internal.h>
33 #include <babeltrace/object-internal.h>
34 #include <babeltrace/compiler-internal.h>
35 #include <babeltrace/object.h>
36 #include <babeltrace/assert-internal.h>
37 #include <babeltrace/assert-pre-internal.h>
38 #include <stdlib.h>
39 #include <glib.h>
40
41 static
42 void destroy_connection(struct bt_object *obj)
43 {
44 struct bt_connection *connection = container_of(obj,
45 struct bt_connection, base);
46
47 BT_LIB_LOGD("Destroying connection: %!+x", connection);
48
49 /*
50 * Make sure that each notification iterator which was created
51 * for this connection is finalized before we destroy it. Once a
52 * notification iterator is finalized, all its method return
53 * NULL or the BT_NOTIFICATION_ITERATOR_STATUS_CANCELED status.
54 *
55 * Because connections are destroyed before components within a
56 * graph, this ensures that notification iterators are always
57 * finalized before their upstream component.
58 *
59 * Ending the connection does exactly this. We pass `false` to
60 * bt_connection_end() here to avoid removing this connection
61 * from the graph: if we're here, we're already in the graph's
62 * destructor.
63 */
64 bt_connection_end(connection, false);
65 g_ptr_array_free(connection->iterators, TRUE);
66 connection->iterators = NULL;
67
68 /*
69 * No bt_object_put_ref on ports as a connection only holds _weak_
70 * references to them.
71 */
72 g_free(connection);
73 }
74
75 static
76 void try_remove_connection_from_graph(struct bt_connection *connection)
77 {
78 void *graph = (void *) bt_object_borrow_parent(&connection->base);
79
80 if (connection->base.ref_count > 0 ||
81 connection->downstream_port ||
82 connection->upstream_port ||
83 connection->iterators->len > 0) {
84 return;
85 }
86
87 /*
88 * At this point we know that:
89 *
90 * 1. The connection is ended (ports were disconnected).
91 * 2. All the notification iterators that this connection
92 * created, if any, are finalized.
93 * 3. The connection's reference count is 0, so only the
94 * parent (graph) owns this connection after this call.
95 *
96 * In other words, no other object than the graph knows this
97 * connection.
98 *
99 * It is safe to remove the connection from the graph, therefore
100 * destroying it.
101 */
102 BT_LIB_LOGD("Removing self from graph's connections: "
103 "%![graph-]+g, %![conn-]+x", graph, connection);
104 bt_graph_remove_connection(graph, connection);
105 }
106
107 static
108 void parent_is_owner(struct bt_object *obj)
109 {
110 struct bt_connection *connection = container_of(obj,
111 struct bt_connection, base);
112
113 try_remove_connection_from_graph(connection);
114 }
115
116 BT_HIDDEN
117 struct bt_connection *bt_connection_create(struct bt_graph *graph,
118 struct bt_port *upstream_port,
119 struct bt_port *downstream_port)
120 {
121 struct bt_connection *connection = NULL;
122
123 BT_LIB_LOGD("Creating connection: "
124 "%![graph-]+g, %![up-port-]+p, %![down-port-]+p",
125 graph, upstream_port, downstream_port);
126 connection = g_new0(struct bt_connection, 1);
127 if (!connection) {
128 BT_LOGE_STR("Failed to allocate one connection.");
129 goto end;
130 }
131
132 bt_object_init_shared_with_parent(&connection->base,
133 destroy_connection);
134 bt_object_set_parent_is_owner_listener_func(&connection->base,
135 parent_is_owner);
136 connection->iterators = g_ptr_array_new();
137 if (!connection->iterators) {
138 BT_LOGE_STR("Failed to allocate a GPtrArray.");
139 BT_OBJECT_PUT_REF_AND_RESET(connection);
140 goto end;
141 }
142
143 /* Weak references are taken, see comment in header. */
144 connection->upstream_port = upstream_port;
145 connection->downstream_port = downstream_port;
146 BT_LIB_LOGD("Setting upstream port's connection: %!+p", upstream_port);
147 bt_port_set_connection(upstream_port, connection);
148 BT_LIB_LOGD("Setting downstream port's connection: %!+p",
149 downstream_port);
150 bt_port_set_connection(downstream_port, connection);
151 bt_object_set_parent(&connection->base, &graph->base);
152 BT_LIB_LOGD("Created connection: %!+x", connection);
153
154 end:
155 return connection;
156 }
157
158 BT_HIDDEN
159 void bt_connection_end(struct bt_connection *conn, bool try_remove_from_graph)
160 {
161 struct bt_component *downstream_comp = NULL;
162 struct bt_component *upstream_comp = NULL;
163 struct bt_port *downstream_port = conn->downstream_port;
164 struct bt_port *upstream_port = conn->upstream_port;
165 struct bt_graph *graph = bt_connection_borrow_graph(conn);
166 size_t i;
167
168 BT_LIB_LOGD("Ending connection: %!+x, try-remove-from-graph=%d",
169 conn, try_remove_from_graph);
170
171 /*
172 * Any of the following notification callback functions could
173 * remove one of the connection's ports from its component. To
174 * make sure that at least logging in called functions works
175 * with existing objects, get a local reference on both ports.
176 */
177 bt_object_get_ref(downstream_port);
178 bt_object_get_ref(upstream_port);
179
180 if (downstream_port) {
181 BT_LIB_LOGD("Disconnecting connection's downstream port: %!+p",
182 downstream_port);
183 downstream_comp = bt_port_borrow_component(downstream_port);
184 bt_port_set_connection(downstream_port, NULL);
185 conn->downstream_port = NULL;
186 }
187
188 if (upstream_port) {
189 BT_LIB_LOGD("Disconnecting connection's upstream port: %!+p",
190 upstream_port);
191 upstream_comp = bt_port_borrow_component(upstream_port);
192 bt_port_set_connection(upstream_port, NULL);
193 conn->upstream_port = NULL;
194 }
195
196 if (downstream_comp && conn->notified_downstream_port_connected &&
197 !conn->notified_downstream_port_disconnected) {
198 /* bt_component_port_disconnected() logs details */
199 bt_component_port_disconnected(downstream_comp,
200 downstream_port);
201 conn->notified_downstream_port_disconnected = true;
202 }
203
204 if (upstream_comp && conn->notified_upstream_port_connected &&
205 !conn->notified_upstream_port_disconnected) {
206 /* bt_component_port_disconnected() logs details */
207 bt_component_port_disconnected(upstream_comp, upstream_port);
208 conn->notified_upstream_port_disconnected = true;
209 }
210
211 BT_ASSERT(graph);
212
213 if (conn->notified_graph_ports_connected &&
214 !conn->notified_graph_ports_disconnected) {
215 /* bt_graph_notify_ports_disconnected() logs details */
216 bt_graph_notify_ports_disconnected(graph, upstream_comp,
217 downstream_comp, upstream_port, downstream_port);
218 conn->notified_graph_ports_disconnected = true;
219 }
220
221 /*
222 * It is safe to put the local port references now that we don't
223 * need them anymore. This could indeed destroy them.
224 */
225 bt_object_put_ref(downstream_port);
226 bt_object_put_ref(upstream_port);
227
228 /*
229 * Because this connection is ended, finalize (cancel) each
230 * notification iterator created from it.
231 */
232 for (i = 0; i < conn->iterators->len; i++) {
233 struct bt_self_component_port_input_notification_iterator *iterator =
234 g_ptr_array_index(conn->iterators, i);
235
236 BT_LIB_LOGD("Finalizing notification iterator created by "
237 "this ended connection: %![iter-]+i", iterator);
238 bt_self_component_port_input_notification_iterator_finalize(
239 iterator);
240
241 /*
242 * Make sure this iterator does not try to remove itself
243 * from this connection's iterators on destruction
244 * because this connection won't exist anymore.
245 */
246 bt_self_component_port_input_notification_iterator_set_connection(
247 iterator, NULL);
248 }
249
250 g_ptr_array_set_size(conn->iterators, 0);
251
252 if (try_remove_from_graph) {
253 try_remove_connection_from_graph(conn);
254 }
255 }
256
257 struct bt_port_output *bt_connection_borrow_upstream_port(
258 struct bt_connection *connection)
259 {
260 BT_ASSERT_PRE_NON_NULL(connection, "Connection");
261 return (void *) connection->upstream_port;
262 }
263
264 struct bt_port_input *bt_connection_borrow_downstream_port(
265 struct bt_connection *connection)
266 {
267 BT_ASSERT_PRE_NON_NULL(connection, "Connection");
268 return (void *) connection->downstream_port;
269 }
270
271 BT_HIDDEN
272 void bt_connection_remove_iterator(struct bt_connection *conn,
273 struct bt_self_component_port_input_notification_iterator *iterator)
274 {
275 g_ptr_array_remove(conn->iterators, iterator);
276 BT_LIB_LOGV("Removed notification iterator from connection: "
277 "%![conn-]+x, %![iter-]+i", conn, iterator);
278 try_remove_connection_from_graph(conn);
279 }
280
281 bt_bool bt_connection_is_ended(struct bt_connection *connection)
282 {
283 return !connection->downstream_port && !connection->upstream_port;
284 }
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