lib/graph/connection.c

   1 /*
   2  * connection.c
   3  *
   4  * Babeltrace Connection
   5  *
   6  * Copyright 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   7  *
   8  * Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
   9  *
  10  * Permission is hereby granted, free of charge, to any person obtaining a copy
  11  * of this software and associated documentation files (the "Software"), to deal
  12  * in the Software without restriction, including without limitation the rights
  13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14  * copies of the Software, and to permit persons to whom the Software is
  15  * furnished to do so, subject to the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be included in
  18  * all copies or substantial portions of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  23  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  26  * SOFTWARE.
  27  */
  28
  29 #define BT_LOG_TAG "CONNECTION"
  30 #include <babeltrace/lib-logging-internal.h>
  31
  32 #include <babeltrace/graph/notification-iterator-internal.h>
  33 #include <babeltrace/graph/component-internal.h>
  34 #include <babeltrace/graph/component-source-internal.h>
  35 #include <babeltrace/graph/component-filter-internal.h>
  36 #include <babeltrace/graph/connection-internal.h>
  37 #include <babeltrace/graph/private-connection.h>
  38 #include <babeltrace/graph/graph-internal.h>
  39 #include <babeltrace/graph/port-internal.h>
  40 #include <babeltrace/object-internal.h>
  41 #include <babeltrace/compiler-internal.h>
  42 #include <stdlib.h>
  43 #include <glib.h>
  44
  45 static
  46 void bt_connection_destroy(struct bt_object *obj)
  47 {
  48         struct bt_connection *connection = container_of(obj,
  49                         struct bt_connection, base);
  50         size_t i;
  51
  52         BT_LOGD("Destroying connection: addr=%p", connection);
  53
  54         /*
  55          * Make sure that each notification iterator which was created
  56          * for this connection is finalized before we destroy it. Once a
  57          * notification iterator is finalized, all its method return
  58          * NULL or the BT_NOTIFICATION_ITERATOR_STATUS_CANCELED status.
  59          *
  60          * Because connections are destroyed before components within a
  61          * graph, this ensures that notification iterators are always
  62          * finalized before their upstream component.
  63          */
  64         if (connection->iterators) {
  65                 for (i = 0; i < connection->iterators->len; i++) {
  66                         struct bt_notification_iterator *iterator =
  67                                 g_ptr_array_index(connection->iterators, i);
  68
  69                         BT_LOGD("Finalizing notification iterator created by this connection: "
  70                                 "iter-addr=%p", iterator);
  71                         bt_notification_iterator_finalize(iterator);
  72
  73                         /*
  74                          * Make sure this iterator does not try to
  75                          * remove itself from this connection's
  76                          * iterators on destruction because this
  77                          * connection won't exist anymore.
  78                          */
  79                         bt_notification_iterator_set_connection(iterator,
  80                                 NULL);
  81                 }
  82
  83                 g_ptr_array_free(connection->iterators, TRUE);
  84         }
  85
  86         /*
  87          * No bt_put on ports as a connection only holds _weak_ references
  88          * to them.
  89          */
  90         g_free(connection);
  91 }
  92
  93 static
  94 void bt_connection_try_remove_from_graph(struct bt_connection *connection)
  95 {
  96         void *graph = bt_object_borrow_parent(&connection->base);
  97
  98         if (connection->base.ref_count.count > 0 ||
  99                         connection->downstream_port ||
 100                         connection->upstream_port ||
 101                         connection->iterators->len > 0) {
 102                 return;
 103         }
 104
 105         /*
 106          * At this point we know that:
 107          *
 108          * 1. The connection is ended (ports were disconnected).
 109          * 2. All the notification iterators that this connection
 110          *    created, if any, are finalized.
 111          * 3. The connection's reference count is 0, so only the
 112          *    parent (graph) owns this connection after this call.
 113          *
 114          * In other words, no other object than the graph knows this
 115          * connection.
 116          *
 117          * It is safe to remove the connection from the graph, therefore
 118          * destroying it.
 119          */
 120         BT_LOGD("Removing self from graph's connections: "
 121                 "graph-addr=%p, conn-addr=%p", graph, connection);
 122         bt_graph_remove_connection(graph, connection);
 123 }
 124
 125 static
 126 void bt_connection_parent_is_owner(struct bt_object *obj)
 127 {
 128         struct bt_connection *connection = container_of(obj,
 129                         struct bt_connection, base);
 130
 131         bt_connection_try_remove_from_graph(connection);
 132 }
 133
 134 struct bt_connection *bt_connection_from_private_connection(
 135                 struct bt_private_connection *private_connection)
 136 {
 137         return bt_get(bt_connection_from_private(private_connection));
 138 }
 139
 140 BT_HIDDEN
 141 struct bt_connection *bt_connection_create(
 142                 struct bt_graph *graph,
 143                 struct bt_port *upstream_port,
 144                 struct bt_port *downstream_port)
 145 {
 146         struct bt_connection *connection = NULL;
 147
 148         if (bt_port_get_type(upstream_port) != BT_PORT_TYPE_OUTPUT) {
 149                 BT_LOGW_STR("Invalid parameter: upstream port is not an output port.");
 150                 goto end;
 151         }
 152         if (bt_port_get_type(downstream_port) != BT_PORT_TYPE_INPUT) {
 153                 BT_LOGW_STR("Invalid parameter: downstream port is not an input port.");
 154                 goto end;
 155         }
 156
 157         BT_LOGD("Creating connection: "
 158                 "graph-addr=%p, upstream-port-addr=%p, uptream-port-name=\"%s\", "
 159                 "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 160                 graph, upstream_port, bt_port_get_name(upstream_port),
 161                 downstream_port, bt_port_get_name(downstream_port));
 162         connection = g_new0(struct bt_connection, 1);
 163         if (!connection) {
 164                 BT_LOGE_STR("Failed to allocate one connection.");
 165                 goto end;
 166         }
 167
 168         bt_object_init(connection, bt_connection_destroy);
 169         bt_object_set_parent_is_owner_listener(connection,
 170                 bt_connection_parent_is_owner);
 171         connection->iterators = g_ptr_array_new();
 172         if (!connection->iterators) {
 173                 BT_LOGE_STR("Failed to allocate a GPtrArray.");
 174                 BT_PUT(connection);
 175                 goto end;
 176         }
 177
 178         /* Weak references are taken, see comment in header. */
 179         connection->upstream_port = upstream_port;
 180         connection->downstream_port = downstream_port;
 181         BT_LOGD_STR("Setting upstream port's connection.");
 182         bt_port_set_connection(upstream_port, connection);
 183         BT_LOGD_STR("Setting downstream port's connection.");
 184         bt_port_set_connection(downstream_port, connection);
 185         bt_object_set_parent(connection, &graph->base);
 186         BT_LOGD("Created connection: "
 187                 "graph-addr=%p, upstream-port-addr=%p, uptream-port-name=\"%s\", "
 188                 "downstream-port-addr=%p, downstream-port-name=\"%s\", "
 189                 "conn-addr=%p",
 190                 graph, upstream_port, bt_port_get_name(upstream_port),
 191                 downstream_port, bt_port_get_name(downstream_port),
 192                 connection);
 193
 194 end:
 195         return connection;
 196 }
 197
 198 BT_HIDDEN
 199 void bt_connection_disconnect_ports(struct bt_connection *conn)
 200 {
 201         struct bt_component *downstream_comp = NULL;
 202         struct bt_component *upstream_comp = NULL;
 203         struct bt_port *downstream_port = conn->downstream_port;
 204         struct bt_port *upstream_port = conn->upstream_port;
 205         struct bt_graph *graph = (void *) bt_object_borrow_parent(conn);
 206         size_t i;
 207
 208         if (downstream_port) {
 209                 downstream_comp = bt_port_get_component(downstream_port);
 210                 bt_port_set_connection(downstream_port, NULL);
 211                 conn->downstream_port = NULL;
 212         }
 213
 214         if (upstream_port) {
 215                 upstream_comp = bt_port_get_component(upstream_port);
 216                 bt_port_set_connection(upstream_port, NULL);
 217                 conn->upstream_port = NULL;
 218         }
 219
 220         if (downstream_comp) {
 221                 /* bt_component_port_disconnected() logs details */
 222                 bt_component_port_disconnected(downstream_comp,
 223                         downstream_port);
 224         }
 225
 226         if (upstream_comp) {
 227                 /* bt_component_port_disconnected() logs details */
 228                 bt_component_port_disconnected(upstream_comp, upstream_port);
 229         }
 230
 231         assert(graph);
 232         /* bt_graph_notify_ports_disconnected() logs details */
 233         bt_graph_notify_ports_disconnected(graph, upstream_comp,
 234                 downstream_comp, upstream_port, downstream_port);
 235         bt_put(downstream_comp);
 236         bt_put(upstream_comp);
 237
 238         /*
 239          * Because this connection is ended, finalize (cancel) each
 240          * notification iterator created from it.
 241          */
 242         for (i = 0; i < conn->iterators->len; i++) {
 243                 struct bt_notification_iterator *iterator =
 244                         g_ptr_array_index(conn->iterators, i);
 245
 246                 BT_LOGD("Finalizing notification iterator created by this ended connection: "
 247                         "conn-addr=%p, iter-addr=%p", conn, iterator);
 248                 bt_notification_iterator_finalize(iterator);
 249
 250                 /*
 251                  * Make sure this iterator does not try to remove itself
 252                  * from this connection's iterators on destruction
 253                  * because this connection won't exist anymore.
 254                  */
 255                 bt_notification_iterator_set_connection(iterator,
 256                         NULL);
 257         }
 258
 259         g_ptr_array_set_size(conn->iterators, 0);
 260         bt_connection_try_remove_from_graph(conn);
 261 }
 262
 263 struct bt_port *bt_connection_get_upstream_port(
 264                 struct bt_connection *connection)
 265 {
 266         return connection ? bt_get(connection->upstream_port) : NULL;
 267 }
 268
 269 struct bt_port *bt_connection_get_downstream_port(
 270                 struct bt_connection *connection)
 271 {
 272         return connection ? bt_get(connection->downstream_port) : NULL;
 273 }
 274
 275 struct bt_notification_iterator *
 276 bt_private_connection_create_notification_iterator(
 277                 struct bt_private_connection *private_connection,
 278                 const enum bt_notification_type *notification_types)
 279 {
 280         enum bt_component_class_type upstream_comp_class_type;
 281         struct bt_notification_iterator *iterator = NULL;
 282         struct bt_port *upstream_port = NULL;
 283         struct bt_component *upstream_component = NULL;
 284         struct bt_component_class *upstream_comp_class = NULL;
 285         struct bt_connection *connection = NULL;
 286         bt_component_class_notification_iterator_init_method init_method = NULL;
 287         static const enum bt_notification_type all_notif_types[] = {
 288                 BT_NOTIFICATION_TYPE_ALL,
 289                 BT_NOTIFICATION_TYPE_SENTINEL,
 290         };
 291
 292         if (!private_connection) {
 293                 BT_LOGW_STR("Invalid parameter: private connection is NULL.");
 294                 goto error;
 295         }
 296
 297         if (!notification_types) {
 298                 BT_LOGD_STR("No notification types: subscribing to all notifications.");
 299                 notification_types = all_notif_types;
 300         }
 301
 302         connection = bt_connection_from_private(private_connection);
 303         if (!connection->upstream_port || !connection->downstream_port) {
 304                 BT_LOGW("Invalid parameter: connection is ended: "
 305                         "conn-addr=%p", connection);
 306                 goto error;
 307         }
 308
 309         upstream_port = connection->upstream_port;
 310         assert(upstream_port);
 311         upstream_component = bt_port_get_component(upstream_port);
 312         assert(upstream_component);
 313         upstream_comp_class = upstream_component->class;
 314         BT_LOGD("Creating notification iterator from connection: "
 315                 "conn-addr=%p, upstream-port-addr=%p, "
 316                 "upstream-port-name=\"%s\", upstream-comp-addr=%p, "
 317                 "upstream-comp-name=\"%s\"",
 318                 connection, connection->upstream_port,
 319                 bt_port_get_name(connection->upstream_port),
 320                 upstream_component, bt_component_get_name(upstream_component));
 321         upstream_comp_class_type =
 322                 bt_component_get_class_type(upstream_component);
 323         if (upstream_comp_class_type != BT_COMPONENT_CLASS_TYPE_SOURCE &&
 324                         upstream_comp_class_type != BT_COMPONENT_CLASS_TYPE_FILTER) {
 325                 /* Unsupported operation. */
 326                 BT_LOGW("Upstream component's class is not a source or filter component class: "
 327                         "comp-class-type=%s",
 328                         bt_component_class_type_string(upstream_comp_class_type));
 329                 goto error;
 330         }
 331
 332         iterator = bt_notification_iterator_create(upstream_component,
 333                 upstream_port, notification_types, connection);
 334         if (!iterator) {
 335                 BT_LOGW("Cannot create notification iterator from connection.");
 336                 goto error;
 337         }
 338
 339         switch (upstream_comp_class_type) {
 340         case BT_COMPONENT_CLASS_TYPE_SOURCE:
 341         {
 342                 struct bt_component_class_source *source_class =
 343                         container_of(upstream_comp_class,
 344                                 struct bt_component_class_source, parent);
 345                 init_method = source_class->methods.iterator.init;
 346                 break;
 347         }
 348         case BT_COMPONENT_CLASS_TYPE_FILTER:
 349         {
 350                 struct bt_component_class_filter *filter_class =
 351                         container_of(upstream_comp_class,
 352                                 struct bt_component_class_filter, parent);
 353                 init_method = filter_class->methods.iterator.init;
 354                 break;
 355         }
 356         default:
 357                 /* Unreachable. */
 358                 abort();
 359         }
 360
 361         if (init_method) {
 362                 enum bt_notification_iterator_status status;
 363
 364                 BT_LOGD("Calling user's initialization method: iter-addr=%p",
 365                         iterator);
 366                 status = init_method(
 367                         bt_private_notification_iterator_from_notification_iterator(iterator),
 368                         bt_private_port_from_port(upstream_port));
 369                 BT_LOGD("User method returned: status=%s",
 370                         bt_notification_iterator_status_string(status));
 371                 if (status < 0) {
 372                         BT_LOGW_STR("Initialization method failed.");
 373                         goto error;
 374                 }
 375         }
 376
 377         g_ptr_array_add(connection->iterators, iterator);
 378         BT_LOGD("Created notification iterator from connection: "
 379                 "conn-addr=%p, upstream-port-addr=%p, "
 380                 "upstream-port-name=\"%s\", upstream-comp-addr=%p, "
 381                 "upstream-comp-name=\"%s\", iter-addr=%p",
 382                 connection, connection->upstream_port,
 383                 bt_port_get_name(connection->upstream_port),
 384                 upstream_component, bt_component_get_name(upstream_component),
 385                 iterator);
 386         goto end;
 387
 388 error:
 389         BT_PUT(iterator);
 390
 391 end:
 392         bt_put(upstream_component);
 393         return iterator;
 394 }
 395
 396 BT_HIDDEN
 397 void bt_connection_remove_iterator(struct bt_connection *conn,
 398                 struct bt_notification_iterator *iterator)
 399 {
 400         g_ptr_array_remove(conn->iterators, iterator);
 401         BT_LOGV("Removed notification iterator from connection: "
 402                 "conn-addr=%p, iter-addr=%p", conn, iterator);
 403         bt_connection_try_remove_from_graph(conn);
 404 }