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 <babeltrace/assert-internal.h>
  43 #include <stdlib.h>
  44 #include <glib.h>
  45
  46 static
  47 void bt_connection_destroy(struct bt_object *obj)
  48 {
  49         struct bt_connection *connection = container_of(obj,
  50                         struct bt_connection, base);
  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          * Ending the connection does exactly this. We pass `false` to
  65          * bt_connection_end() here to avoid removing this connection
  66          * from the graph: if we're here, we're already in the graph's
  67          * destructor.
  68          */
  69         bt_connection_end(connection, false);
  70         g_ptr_array_free(connection->iterators, TRUE);
  71
  72         /*
  73          * No bt_put on ports as a connection only holds _weak_
  74          * references to them.
  75          */
  76         g_free(connection);
  77 }
  78
  79 static
  80 void bt_connection_try_remove_from_graph(struct bt_connection *connection)
  81 {
  82         void *graph = bt_object_borrow_parent(&connection->base);
  83
  84         if (connection->base.ref_count.count > 0 ||
  85                         connection->downstream_port ||
  86                         connection->upstream_port ||
  87                         connection->iterators->len > 0) {
  88                 return;
  89         }
  90
  91         /*
  92          * At this point we know that:
  93          *
  94          * 1. The connection is ended (ports were disconnected).
  95          * 2. All the notification iterators that this connection
  96          *    created, if any, are finalized.
  97          * 3. The connection's reference count is 0, so only the
  98          *    parent (graph) owns this connection after this call.
  99          *
 100          * In other words, no other object than the graph knows this
 101          * connection.
 102          *
 103          * It is safe to remove the connection from the graph, therefore
 104          * destroying it.
 105          */
 106         BT_LOGD("Removing self from graph's connections: "
 107                 "graph-addr=%p, conn-addr=%p", graph, connection);
 108         bt_graph_remove_connection(graph, connection);
 109 }
 110
 111 static
 112 void bt_connection_parent_is_owner(struct bt_object *obj)
 113 {
 114         struct bt_connection *connection = container_of(obj,
 115                         struct bt_connection, base);
 116
 117         bt_connection_try_remove_from_graph(connection);
 118 }
 119
 120 struct bt_connection *bt_connection_from_private(
 121                 struct bt_private_connection *private_connection)
 122 {
 123         return bt_get(bt_connection_borrow_from_private(private_connection));
 124 }
 125
 126 BT_HIDDEN
 127 struct bt_connection *bt_connection_create(
 128                 struct bt_graph *graph,
 129                 struct bt_port *upstream_port,
 130                 struct bt_port *downstream_port)
 131 {
 132         struct bt_connection *connection = NULL;
 133
 134         if (bt_port_get_type(upstream_port) != BT_PORT_TYPE_OUTPUT) {
 135                 BT_LOGW_STR("Invalid parameter: upstream port is not an output port.");
 136                 goto end;
 137         }
 138         if (bt_port_get_type(downstream_port) != BT_PORT_TYPE_INPUT) {
 139                 BT_LOGW_STR("Invalid parameter: downstream port is not an input port.");
 140                 goto end;
 141         }
 142
 143         BT_LOGD("Creating connection: "
 144                 "graph-addr=%p, upstream-port-addr=%p, uptream-port-name=\"%s\", "
 145                 "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 146                 graph, upstream_port, bt_port_get_name(upstream_port),
 147                 downstream_port, bt_port_get_name(downstream_port));
 148         connection = g_new0(struct bt_connection, 1);
 149         if (!connection) {
 150                 BT_LOGE_STR("Failed to allocate one connection.");
 151                 goto end;
 152         }
 153
 154         bt_object_init(connection, bt_connection_destroy);
 155         bt_object_set_parent_is_owner_listener(connection,
 156                 bt_connection_parent_is_owner);
 157         connection->iterators = g_ptr_array_new();
 158         if (!connection->iterators) {
 159                 BT_LOGE_STR("Failed to allocate a GPtrArray.");
 160                 BT_PUT(connection);
 161                 goto end;
 162         }
 163
 164         /* Weak references are taken, see comment in header. */
 165         connection->upstream_port = upstream_port;
 166         connection->downstream_port = downstream_port;
 167         BT_LOGD_STR("Setting upstream port's connection.");
 168         bt_port_set_connection(upstream_port, connection);
 169         BT_LOGD_STR("Setting downstream port's connection.");
 170         bt_port_set_connection(downstream_port, connection);
 171         bt_object_set_parent(connection, &graph->base);
 172         BT_LOGD("Created connection: "
 173                 "graph-addr=%p, upstream-port-addr=%p, uptream-port-name=\"%s\", "
 174                 "downstream-port-addr=%p, downstream-port-name=\"%s\", "
 175                 "conn-addr=%p",
 176                 graph, upstream_port, bt_port_get_name(upstream_port),
 177                 downstream_port, bt_port_get_name(downstream_port),
 178                 connection);
 179
 180 end:
 181         return connection;
 182 }
 183
 184 BT_HIDDEN
 185 void bt_connection_end(struct bt_connection *conn,
 186                 bool try_remove_from_graph)
 187 {
 188         struct bt_component *downstream_comp = NULL;
 189         struct bt_component *upstream_comp = NULL;
 190         struct bt_port *downstream_port = conn->downstream_port;
 191         struct bt_port *upstream_port = conn->upstream_port;
 192         struct bt_graph *graph = bt_connection_borrow_graph(conn);
 193         size_t i;
 194
 195         BT_LOGD("Ending connection: conn-addr=%p, try-remove-from-graph=%d",
 196                 conn, try_remove_from_graph);
 197
 198         if (downstream_port) {
 199                 BT_LOGD("Disconnecting connection's downstream port: "
 200                         "port-addr=%p, port-name=\"%s\"",
 201                         downstream_port, bt_port_get_name(downstream_port));
 202                 downstream_comp = bt_port_get_component(downstream_port);
 203                 bt_port_set_connection(downstream_port, NULL);
 204                 conn->downstream_port = NULL;
 205         }
 206
 207         if (upstream_port) {
 208                 BT_LOGD("Disconnecting connection's upstream port: "
 209                         "port-addr=%p, port-name=\"%s\"",
 210                         upstream_port, bt_port_get_name(upstream_port));
 211                 upstream_comp = bt_port_get_component(upstream_port);
 212                 bt_port_set_connection(upstream_port, NULL);
 213                 conn->upstream_port = NULL;
 214         }
 215
 216         if (downstream_comp) {
 217                 /* bt_component_port_disconnected() logs details */
 218                 bt_component_port_disconnected(downstream_comp,
 219                         downstream_port);
 220         }
 221
 222         if (upstream_comp) {
 223                 /* bt_component_port_disconnected() logs details */
 224                 bt_component_port_disconnected(upstream_comp, upstream_port);
 225         }
 226
 227         BT_ASSERT(graph);
 228         /* bt_graph_notify_ports_disconnected() logs details */
 229         bt_graph_notify_ports_disconnected(graph, upstream_comp,
 230                 downstream_comp, upstream_port, downstream_port);
 231         bt_put(downstream_comp);
 232         bt_put(upstream_comp);
 233
 234         /*
 235          * Because this connection is ended, finalize (cancel) each
 236          * notification iterator created from it.
 237          */
 238         for (i = 0; i < conn->iterators->len; i++) {
 239                 struct bt_notification_iterator_private_connection *iterator =
 240                         g_ptr_array_index(conn->iterators, i);
 241
 242                 BT_LOGD("Finalizing notification iterator created by this ended connection: "
 243                         "conn-addr=%p, iter-addr=%p", conn, iterator);
 244                 bt_private_connection_notification_iterator_finalize(iterator);
 245
 246                 /*
 247                  * Make sure this iterator does not try to remove itself
 248                  * from this connection's iterators on destruction
 249                  * because this connection won't exist anymore.
 250                  */
 251                 bt_private_connection_notification_iterator_set_connection(
 252                         iterator, NULL);
 253         }
 254
 255         g_ptr_array_set_size(conn->iterators, 0);
 256
 257         if (try_remove_from_graph) {
 258                 bt_connection_try_remove_from_graph(conn);
 259         }
 260 }
 261
 262 struct bt_port *bt_connection_get_upstream_port(
 263                 struct bt_connection *connection)
 264 {
 265         return connection ? bt_get(connection->upstream_port) : NULL;
 266 }
 267
 268 struct bt_port *bt_connection_get_downstream_port(
 269                 struct bt_connection *connection)
 270 {
 271         return connection ? bt_get(connection->downstream_port) : NULL;
 272 }
 273
 274 enum bt_connection_status
 275 bt_private_connection_create_notification_iterator(
 276                 struct bt_private_connection *private_connection,
 277                 const enum bt_notification_type *notification_types,
 278                 struct bt_notification_iterator **user_iterator)
 279 {
 280         enum bt_component_class_type upstream_comp_class_type;
 281         struct bt_notification_iterator_private_connection *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         enum bt_connection_status status;
 288         static const enum bt_notification_type all_notif_types[] = {
 289                 BT_NOTIFICATION_TYPE_ALL,
 290                 BT_NOTIFICATION_TYPE_SENTINEL,
 291         };
 292
 293         if (!private_connection) {
 294                 BT_LOGW_STR("Invalid parameter: private connection is NULL.");
 295                 status = BT_CONNECTION_STATUS_INVALID;
 296                 goto end;
 297         }
 298
 299         if (!user_iterator) {
 300                 BT_LOGW_STR("Invalid parameter: notification iterator pointer is NULL.");
 301                 status = BT_CONNECTION_STATUS_INVALID;
 302                 goto end;
 303         }
 304
 305         connection = bt_connection_borrow_from_private(private_connection);
 306
 307         if (bt_graph_is_canceled(bt_connection_borrow_graph(connection))) {
 308                 BT_LOGW("Cannot create notification iterator from connection: "
 309                         "connection's graph is canceled: "
 310                         "conn-addr=%p, upstream-port-addr=%p, "
 311                         "upstream-port-name=\"%s\", upstream-comp-addr=%p, "
 312                         "upstream-comp-name=\"%s\", graph-addr=%p",
 313                         connection, connection->upstream_port,
 314                         bt_port_get_name(connection->upstream_port),
 315                         upstream_component,
 316                         bt_component_get_name(upstream_component),
 317                         bt_connection_borrow_graph(connection));
 318                 status = BT_CONNECTION_STATUS_GRAPH_IS_CANCELED;
 319                 goto end;
 320         }
 321
 322         if (bt_connection_is_ended(connection)) {
 323                 BT_LOGW("Invalid parameter: connection is ended: "
 324                         "conn-addr=%p", connection);
 325                 status = BT_CONNECTION_STATUS_IS_ENDED;
 326                 goto end;
 327         }
 328
 329         if (!notification_types) {
 330                 BT_LOGD_STR("No notification types: subscribing to all notifications.");
 331                 notification_types = all_notif_types;
 332         }
 333
 334         upstream_port = connection->upstream_port;
 335         BT_ASSERT(upstream_port);
 336         upstream_component = bt_port_get_component(upstream_port);
 337         BT_ASSERT(upstream_component);
 338         upstream_comp_class = upstream_component->class;
 339         BT_LOGD("Creating notification iterator from connection: "
 340                 "conn-addr=%p, upstream-port-addr=%p, "
 341                 "upstream-port-name=\"%s\", upstream-comp-addr=%p, "
 342                 "upstream-comp-name=\"%s\"",
 343                 connection, connection->upstream_port,
 344                 bt_port_get_name(connection->upstream_port),
 345                 upstream_component, bt_component_get_name(upstream_component));
 346         upstream_comp_class_type =
 347                 bt_component_get_class_type(upstream_component);
 348         BT_ASSERT(upstream_comp_class_type == BT_COMPONENT_CLASS_TYPE_SOURCE ||
 349                         upstream_comp_class_type == BT_COMPONENT_CLASS_TYPE_FILTER);
 350         status = bt_private_connection_notification_iterator_create(upstream_component,
 351                 upstream_port, notification_types, connection, &iterator);
 352         if (status != BT_CONNECTION_STATUS_OK) {
 353                 BT_LOGW("Cannot create notification iterator from connection.");
 354                 goto end;
 355         }
 356
 357         switch (upstream_comp_class_type) {
 358         case BT_COMPONENT_CLASS_TYPE_SOURCE:
 359         {
 360                 struct bt_component_class_source *source_class =
 361                         container_of(upstream_comp_class,
 362                                 struct bt_component_class_source, parent);
 363                 init_method = source_class->methods.iterator.init;
 364                 break;
 365         }
 366         case BT_COMPONENT_CLASS_TYPE_FILTER:
 367         {
 368                 struct bt_component_class_filter *filter_class =
 369                         container_of(upstream_comp_class,
 370                                 struct bt_component_class_filter, parent);
 371                 init_method = filter_class->methods.iterator.init;
 372                 break;
 373         }
 374         default:
 375                 /* Unreachable. */
 376                 BT_LOGF("Unknown component class type: type=%d",
 377                         upstream_comp_class_type);
 378                 abort();
 379         }
 380
 381         if (init_method) {
 382                 enum bt_notification_iterator_status iter_status;
 383
 384                 BT_LOGD("Calling user's initialization method: iter-addr=%p",
 385                         iterator);
 386                 iter_status = init_method(
 387                         bt_private_connection_private_notification_iterator_from_notification_iterator((void *) iterator),
 388                         bt_private_port_from_port(upstream_port));
 389                 BT_LOGD("User method returned: status=%s",
 390                         bt_notification_iterator_status_string(iter_status));
 391                 if (iter_status != BT_NOTIFICATION_ITERATOR_STATUS_OK) {
 392                         BT_LOGW_STR("Initialization method failed.");
 393                         status = bt_connection_status_from_notification_iterator_status(
 394                                 iter_status);
 395                         goto end;
 396                 }
 397         }
 398
 399         iterator->state = BT_PRIVATE_CONNECTION_NOTIFICATION_ITERATOR_STATE_ACTIVE;
 400         g_ptr_array_add(connection->iterators, iterator);
 401         BT_LOGD("Created notification iterator from connection: "
 402                 "conn-addr=%p, upstream-port-addr=%p, "
 403                 "upstream-port-name=\"%s\", upstream-comp-addr=%p, "
 404                 "upstream-comp-name=\"%s\", iter-addr=%p",
 405                 connection, connection->upstream_port,
 406                 bt_port_get_name(connection->upstream_port),
 407                 upstream_component, bt_component_get_name(upstream_component),
 408                 iterator);
 409
 410         /* Move reference to user */
 411         *user_iterator = (void *) iterator;
 412         iterator = NULL;
 413
 414 end:
 415         bt_put(upstream_component);
 416         bt_put(iterator);
 417         return status;
 418 }
 419
 420 BT_HIDDEN
 421 void bt_connection_remove_iterator(struct bt_connection *conn,
 422                 struct bt_notification_iterator_private_connection *iterator)
 423 {
 424         g_ptr_array_remove(conn->iterators, iterator);
 425         BT_LOGV("Removed notification iterator from connection: "
 426                 "conn-addr=%p, iter-addr=%p", conn, iterator);
 427         bt_connection_try_remove_from_graph(conn);
 428 }
 429
 430 bt_bool bt_connection_is_ended(struct bt_connection *connection)
 431 {
 432         return !connection->downstream_port && !connection->upstream_port;
 433 }