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
  51         BT_LOGD("Destroying connection: addr=%p", connection);
  52
  53         /*
  54          * Make sure that each notification iterator which was created
  55          * for this connection is finalized before we destroy it. Once a
  56          * notification iterator is finalized, all its method return
  57          * NULL or the BT_NOTIFICATION_ITERATOR_STATUS_CANCELED status.
  58          *
  59          * Because connections are destroyed before components within a
  60          * graph, this ensures that notification iterators are always
  61          * finalized before their upstream component.
  62          *
  63          * Ending the connection does exactly this. We pass `false` to
  64          * bt_connection_end() here to avoid removing this connection
  65          * from the graph: if we're here, we're already in the graph's
  66          * destructor.
  67          */
  68         bt_connection_end(connection, false);
  69         g_ptr_array_free(connection->iterators, TRUE);
  70
  71         /*
  72          * No bt_put on ports as a connection only holds _weak_
  73          * references to them.
  74          */
  75         g_free(connection);
  76 }
  77
  78 static
  79 void bt_connection_try_remove_from_graph(struct bt_connection *connection)
  80 {
  81         void *graph = bt_object_borrow_parent(&connection->base);
  82
  83         if (connection->base.ref_count.count > 0 ||
  84                         connection->downstream_port ||
  85                         connection->upstream_port ||
  86                         connection->iterators->len > 0) {
  87                 return;
  88         }
  89
  90         /*
  91          * At this point we know that:
  92          *
  93          * 1. The connection is ended (ports were disconnected).
  94          * 2. All the notification iterators that this connection
  95          *    created, if any, are finalized.
  96          * 3. The connection's reference count is 0, so only the
  97          *    parent (graph) owns this connection after this call.
  98          *
  99          * In other words, no other object than the graph knows this
 100          * connection.
 101          *
 102          * It is safe to remove the connection from the graph, therefore
 103          * destroying it.
 104          */
 105         BT_LOGD("Removing self from graph's connections: "
 106                 "graph-addr=%p, conn-addr=%p", graph, connection);
 107         bt_graph_remove_connection(graph, connection);
 108 }
 109
 110 static
 111 void bt_connection_parent_is_owner(struct bt_object *obj)
 112 {
 113         struct bt_connection *connection = container_of(obj,
 114                         struct bt_connection, base);
 115
 116         bt_connection_try_remove_from_graph(connection);
 117 }
 118
 119 struct bt_connection *bt_connection_from_private_connection(
 120                 struct bt_private_connection *private_connection)
 121 {
 122         return bt_get(bt_connection_from_private(private_connection));
 123 }
 124
 125 BT_HIDDEN
 126 struct bt_connection *bt_connection_create(
 127                 struct bt_graph *graph,
 128                 struct bt_port *upstream_port,
 129                 struct bt_port *downstream_port)
 130 {
 131         struct bt_connection *connection = NULL;
 132
 133         if (bt_port_get_type(upstream_port) != BT_PORT_TYPE_OUTPUT) {
 134                 BT_LOGW_STR("Invalid parameter: upstream port is not an output port.");
 135                 goto end;
 136         }
 137         if (bt_port_get_type(downstream_port) != BT_PORT_TYPE_INPUT) {
 138                 BT_LOGW_STR("Invalid parameter: downstream port is not an input port.");
 139                 goto end;
 140         }
 141
 142         BT_LOGD("Creating connection: "
 143                 "graph-addr=%p, upstream-port-addr=%p, uptream-port-name=\"%s\", "
 144                 "downstream-port-addr=%p, downstream-port-name=\"%s\"",
 145                 graph, upstream_port, bt_port_get_name(upstream_port),
 146                 downstream_port, bt_port_get_name(downstream_port));
 147         connection = g_new0(struct bt_connection, 1);
 148         if (!connection) {
 149                 BT_LOGE_STR("Failed to allocate one connection.");
 150                 goto end;
 151         }
 152
 153         bt_object_init(connection, bt_connection_destroy);
 154         bt_object_set_parent_is_owner_listener(connection,
 155                 bt_connection_parent_is_owner);
 156         connection->iterators = g_ptr_array_new();
 157         if (!connection->iterators) {
 158                 BT_LOGE_STR("Failed to allocate a GPtrArray.");
 159                 BT_PUT(connection);
 160                 goto end;
 161         }
 162
 163         /* Weak references are taken, see comment in header. */
 164         connection->upstream_port = upstream_port;
 165         connection->downstream_port = downstream_port;
 166         BT_LOGD_STR("Setting upstream port's connection.");
 167         bt_port_set_connection(upstream_port, connection);
 168         BT_LOGD_STR("Setting downstream port's connection.");
 169         bt_port_set_connection(downstream_port, connection);
 170         bt_object_set_parent(connection, &graph->base);
 171         BT_LOGD("Created connection: "
 172                 "graph-addr=%p, upstream-port-addr=%p, uptream-port-name=\"%s\", "
 173                 "downstream-port-addr=%p, downstream-port-name=\"%s\", "
 174                 "conn-addr=%p",
 175                 graph, upstream_port, bt_port_get_name(upstream_port),
 176                 downstream_port, bt_port_get_name(downstream_port),
 177                 connection);
 178
 179 end:
 180         return connection;
 181 }
 182
 183 BT_HIDDEN
 184 void bt_connection_end(struct bt_connection *conn,
 185                 bool try_remove_from_graph)
 186 {
 187         struct bt_component *downstream_comp = NULL;
 188         struct bt_component *upstream_comp = NULL;
 189         struct bt_port *downstream_port = conn->downstream_port;
 190         struct bt_port *upstream_port = conn->upstream_port;
 191         struct bt_graph *graph = bt_connection_borrow_graph(conn);
 192         size_t i;
 193
 194         BT_LOGD("Ending connection: conn-addr=%p, try-remove-from-graph=%d",
 195                 conn, try_remove_from_graph);
 196
 197         if (downstream_port) {
 198                 BT_LOGD("Disconnecting connection's downstream port: "
 199                         "port-addr=%p, port-name=\"%s\"",
 200                         downstream_port, bt_port_get_name(downstream_port));
 201                 downstream_comp = bt_port_get_component(downstream_port);
 202                 bt_port_set_connection(downstream_port, NULL);
 203                 conn->downstream_port = NULL;
 204         }
 205
 206         if (upstream_port) {
 207                 BT_LOGD("Disconnecting connection's upstream port: "
 208                         "port-addr=%p, port-name=\"%s\"",
 209                         upstream_port, bt_port_get_name(upstream_port));
 210                 upstream_comp = bt_port_get_component(upstream_port);
 211                 bt_port_set_connection(upstream_port, NULL);
 212                 conn->upstream_port = NULL;
 213         }
 214
 215         if (downstream_comp) {
 216                 /* bt_component_port_disconnected() logs details */
 217                 bt_component_port_disconnected(downstream_comp,
 218                         downstream_port);
 219         }
 220
 221         if (upstream_comp) {
 222                 /* bt_component_port_disconnected() logs details */
 223                 bt_component_port_disconnected(upstream_comp, upstream_port);
 224         }
 225
 226         assert(graph);
 227         /* bt_graph_notify_ports_disconnected() logs details */
 228         bt_graph_notify_ports_disconnected(graph, upstream_comp,
 229                 downstream_comp, upstream_port, downstream_port);
 230         bt_put(downstream_comp);
 231         bt_put(upstream_comp);
 232
 233         /*
 234          * Because this connection is ended, finalize (cancel) each
 235          * notification iterator created from it.
 236          */
 237         for (i = 0; i < conn->iterators->len; i++) {
 238                 struct bt_notification_iterator *iterator =
 239                         g_ptr_array_index(conn->iterators, i);
 240
 241                 BT_LOGD("Finalizing notification iterator created by this ended connection: "
 242                         "conn-addr=%p, iter-addr=%p", conn, iterator);
 243                 bt_notification_iterator_finalize(iterator);
 244
 245                 /*
 246                  * Make sure this iterator does not try to remove itself
 247                  * from this connection's iterators on destruction
 248                  * because this connection won't exist anymore.
 249                  */
 250                 bt_notification_iterator_set_connection(iterator,
 251                         NULL);
 252         }
 253
 254         g_ptr_array_set_size(conn->iterators, 0);
 255
 256         if (try_remove_from_graph) {
 257                 bt_connection_try_remove_from_graph(conn);
 258         }
 259 }
 260
 261 struct bt_port *bt_connection_get_upstream_port(
 262                 struct bt_connection *connection)
 263 {
 264         return connection ? bt_get(connection->upstream_port) : NULL;
 265 }
 266
 267 struct bt_port *bt_connection_get_downstream_port(
 268                 struct bt_connection *connection)
 269 {
 270         return connection ? bt_get(connection->downstream_port) : NULL;
 271 }
 272
 273 enum bt_connection_status
 274 bt_private_connection_create_notification_iterator(
 275                 struct bt_private_connection *private_connection,
 276                 const enum bt_notification_type *notification_types,
 277                 struct bt_notification_iterator **user_iterator)
 278 {
 279         enum bt_component_class_type upstream_comp_class_type;
 280         struct bt_notification_iterator *iterator = NULL;
 281         struct bt_port *upstream_port = NULL;
 282         struct bt_component *upstream_component = NULL;
 283         struct bt_component_class *upstream_comp_class = NULL;
 284         struct bt_connection *connection = NULL;
 285         bt_component_class_notification_iterator_init_method init_method = NULL;
 286         enum bt_connection_status status;
 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                 status = BT_CONNECTION_STATUS_INVALID;
 295                 goto end;
 296         }
 297
 298         if (!user_iterator) {
 299                 BT_LOGW_STR("Invalid parameter: notification iterator pointer is NULL.");
 300                 status = BT_CONNECTION_STATUS_INVALID;
 301                 goto end;
 302         }
 303
 304         connection = bt_connection_from_private(private_connection);
 305
 306         if (bt_graph_is_canceled(bt_connection_borrow_graph(connection))) {
 307                 BT_LOGW("Cannot create notification iterator from connection: "
 308                         "connection's graph is canceled: "
 309                         "conn-addr=%p, upstream-port-addr=%p, "
 310                         "upstream-port-name=\"%s\", upstream-comp-addr=%p, "
 311                         "upstream-comp-name=\"%s\", graph-addr=%p",
 312                         connection, connection->upstream_port,
 313                         bt_port_get_name(connection->upstream_port),
 314                         upstream_component,
 315                         bt_component_get_name(upstream_component),
 316                         bt_connection_borrow_graph(connection));
 317                 status = BT_CONNECTION_STATUS_GRAPH_IS_CANCELED;
 318                 goto end;
 319         }
 320
 321         if (bt_connection_is_ended(connection)) {
 322                 BT_LOGW("Invalid parameter: connection is ended: "
 323                         "conn-addr=%p", connection);
 324                 status = BT_CONNECTION_STATUS_IS_ENDED;
 325                 goto end;
 326         }
 327
 328         if (!notification_types) {
 329                 BT_LOGD_STR("No notification types: subscribing to all notifications.");
 330                 notification_types = all_notif_types;
 331         }
 332
 333         upstream_port = connection->upstream_port;
 334         assert(upstream_port);
 335         upstream_component = bt_port_get_component(upstream_port);
 336         assert(upstream_component);
 337         upstream_comp_class = upstream_component->class;
 338         BT_LOGD("Creating notification iterator from connection: "
 339                 "conn-addr=%p, upstream-port-addr=%p, "
 340                 "upstream-port-name=\"%s\", upstream-comp-addr=%p, "
 341                 "upstream-comp-name=\"%s\"",
 342                 connection, connection->upstream_port,
 343                 bt_port_get_name(connection->upstream_port),
 344                 upstream_component, bt_component_get_name(upstream_component));
 345         upstream_comp_class_type =
 346                 bt_component_get_class_type(upstream_component);
 347         assert(upstream_comp_class_type == BT_COMPONENT_CLASS_TYPE_SOURCE ||
 348                         upstream_comp_class_type == BT_COMPONENT_CLASS_TYPE_FILTER);
 349         status = bt_notification_iterator_create(upstream_component,
 350                 upstream_port, notification_types, connection, &iterator);
 351         if (status != BT_CONNECTION_STATUS_OK) {
 352                 BT_LOGW("Cannot create notification iterator from connection.");
 353                 goto end;
 354         }
 355
 356         switch (upstream_comp_class_type) {
 357         case BT_COMPONENT_CLASS_TYPE_SOURCE:
 358         {
 359                 struct bt_component_class_source *source_class =
 360                         container_of(upstream_comp_class,
 361                                 struct bt_component_class_source, parent);
 362                 init_method = source_class->methods.iterator.init;
 363                 break;
 364         }
 365         case BT_COMPONENT_CLASS_TYPE_FILTER:
 366         {
 367                 struct bt_component_class_filter *filter_class =
 368                         container_of(upstream_comp_class,
 369                                 struct bt_component_class_filter, parent);
 370                 init_method = filter_class->methods.iterator.init;
 371                 break;
 372         }
 373         default:
 374                 /* Unreachable. */
 375                 BT_LOGF("Unknown component class type: type=%d",
 376                         upstream_comp_class_type);
 377                 abort();
 378         }
 379
 380         if (init_method) {
 381                 enum bt_notification_iterator_status iter_status;
 382
 383                 BT_LOGD("Calling user's initialization method: iter-addr=%p",
 384                         iterator);
 385                 iter_status = init_method(
 386                         bt_private_notification_iterator_from_notification_iterator(iterator),
 387                         bt_private_port_from_port(upstream_port));
 388                 BT_LOGD("User method returned: status=%s",
 389                         bt_notification_iterator_status_string(iter_status));
 390                 if (iter_status != BT_NOTIFICATION_ITERATOR_STATUS_OK) {
 391                         BT_LOGW_STR("Initialization method failed.");
 392                         status = bt_connection_status_from_notification_iterator_status(
 393                                 iter_status);
 394                         goto end;
 395                 }
 396         }
 397
 398         g_ptr_array_add(connection->iterators, iterator);
 399         BT_LOGD("Created notification iterator from connection: "
 400                 "conn-addr=%p, upstream-port-addr=%p, "
 401                 "upstream-port-name=\"%s\", upstream-comp-addr=%p, "
 402                 "upstream-comp-name=\"%s\", iter-addr=%p",
 403                 connection, connection->upstream_port,
 404                 bt_port_get_name(connection->upstream_port),
 405                 upstream_component, bt_component_get_name(upstream_component),
 406                 iterator);
 407
 408         /* Move reference to user */
 409         *user_iterator = iterator;
 410         iterator = NULL;
 411
 412 end:
 413         bt_put(upstream_component);
 414         bt_put(iterator);
 415         return status;
 416 }
 417
 418 BT_HIDDEN
 419 void bt_connection_remove_iterator(struct bt_connection *conn,
 420                 struct bt_notification_iterator *iterator)
 421 {
 422         g_ptr_array_remove(conn->iterators, iterator);
 423         BT_LOGV("Removed notification iterator from connection: "
 424                 "conn-addr=%p, iter-addr=%p", conn, iterator);
 425         bt_connection_try_remove_from_graph(conn);
 426 }
 427
 428 bt_bool bt_connection_is_ended(struct bt_connection *connection)
 429 {
 430         return !connection->downstream_port && !connection->upstream_port;
 431 }