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