--- /dev/null
+/*
+ * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
+ * Copyright 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#define BT_LOG_TAG "CONNECTION"
+#include "lib/lib-logging.h"
+
+#include "common/assert.h"
+#include "lib/assert-pre.h"
+#include <babeltrace2/graph/connection-const.h>
+#include "lib/object.h"
+#include "compat/compiler.h"
+#include <stdlib.h>
+#include <glib.h>
+
+#include "component.h"
+#include "connection.h"
+#include "graph.h"
+#include "message/iterator.h"
+#include "port.h"
+
+static
+void destroy_connection(struct bt_object *obj)
+{
+ struct bt_connection *connection = container_of(obj,
+ struct bt_connection, base);
+
+ BT_LIB_LOGD("Destroying connection: %!+x", connection);
+
+ /*
+ * Make sure that each message iterator which was created for
+ * this connection is finalized before we destroy it. Once a
+ * message iterator is finalized, all its method return NULL or
+ * the BT_MESSAGE_ITERATOR_STATUS_CANCELED status.
+ *
+ * Because connections are destroyed before components within a
+ * graph, this ensures that message iterators are always
+ * finalized before their upstream component.
+ *
+ * Ending the connection does exactly this. We pass `false` to
+ * bt_connection_end() here to avoid removing this connection
+ * from the graph: if we're here, we're already in the graph's
+ * destructor.
+ */
+ bt_connection_end(connection, false);
+ g_ptr_array_free(connection->iterators, TRUE);
+ connection->iterators = NULL;
+
+ /*
+ * No bt_object_put_ref on ports as a connection only holds _weak_
+ * references to them.
+ */
+ g_free(connection);
+}
+
+static
+void try_remove_connection_from_graph(struct bt_connection *connection)
+{
+ void *graph = (void *) bt_object_borrow_parent(&connection->base);
+
+ if (connection->base.ref_count > 0 ||
+ connection->downstream_port ||
+ connection->upstream_port ||
+ connection->iterators->len > 0) {
+ return;
+ }
+
+ /*
+ * At this point we know that:
+ *
+ * 1. The connection is ended (ports were disconnected).
+ * 2. All the message iterators that this connection
+ * created, if any, are finalized.
+ * 3. The connection's reference count is 0, so only the
+ * parent (graph) owns this connection after this call.
+ *
+ * In other words, no other object than the graph knows this
+ * connection.
+ *
+ * It is safe to remove the connection from the graph, therefore
+ * destroying it.
+ */
+ BT_LIB_LOGD("Removing self from graph's connections: "
+ "%![graph-]+g, %![conn-]+x", graph, connection);
+ bt_graph_remove_connection(graph, connection);
+}
+
+static
+void parent_is_owner(struct bt_object *obj)
+{
+ struct bt_connection *connection = container_of(obj,
+ struct bt_connection, base);
+
+ try_remove_connection_from_graph(connection);
+}
+
+BT_HIDDEN
+struct bt_connection *bt_connection_create(struct bt_graph *graph,
+ struct bt_port *upstream_port,
+ struct bt_port *downstream_port)
+{
+ struct bt_connection *connection = NULL;
+
+ BT_LIB_LOGD("Creating connection: "
+ "%![graph-]+g, %![up-port-]+p, %![down-port-]+p",
+ graph, upstream_port, downstream_port);
+ connection = g_new0(struct bt_connection, 1);
+ if (!connection) {
+ BT_LOGE_STR("Failed to allocate one connection.");
+ goto end;
+ }
+
+ bt_object_init_shared_with_parent(&connection->base,
+ destroy_connection);
+ bt_object_set_parent_is_owner_listener_func(&connection->base,
+ parent_is_owner);
+ connection->iterators = g_ptr_array_new();
+ if (!connection->iterators) {
+ BT_LOGE_STR("Failed to allocate a GPtrArray.");
+ BT_OBJECT_PUT_REF_AND_RESET(connection);
+ goto end;
+ }
+
+ /* Weak references are taken, see comment in header. */
+ connection->upstream_port = upstream_port;
+ connection->downstream_port = downstream_port;
+ BT_LIB_LOGD("Setting upstream port's connection: %!+p", upstream_port);
+ bt_port_set_connection(upstream_port, connection);
+ BT_LIB_LOGD("Setting downstream port's connection: %!+p",
+ downstream_port);
+ bt_port_set_connection(downstream_port, connection);
+ bt_object_set_parent(&connection->base, &graph->base);
+ BT_LIB_LOGD("Created connection: %!+x", connection);
+
+end:
+ return connection;
+}
+
+BT_HIDDEN
+void bt_connection_end(struct bt_connection *conn, bool try_remove_from_graph)
+{
+ struct bt_port *downstream_port = conn->downstream_port;
+ struct bt_port *upstream_port = conn->upstream_port;
+ size_t i;
+
+ BT_LIB_LOGD("Ending connection: %!+x, try-remove-from-graph=%d",
+ conn, try_remove_from_graph);
+
+ /*
+ * Any of the following message callback functions could
+ * remove one of the connection's ports from its component. To
+ * make sure that at least logging in called functions works
+ * with existing objects, get a local reference on both ports.
+ */
+ bt_object_get_ref(downstream_port);
+ bt_object_get_ref(upstream_port);
+
+ if (downstream_port) {
+ BT_LIB_LOGD("Disconnecting connection's downstream port: %!+p",
+ downstream_port);
+ bt_port_set_connection(downstream_port, NULL);
+ conn->downstream_port = NULL;
+ }
+
+ if (upstream_port) {
+ BT_LIB_LOGD("Disconnecting connection's upstream port: %!+p",
+ upstream_port);
+ bt_port_set_connection(upstream_port, NULL);
+ conn->upstream_port = NULL;
+ }
+
+ /*
+ * It is safe to put the local port references now that we don't
+ * need them anymore. This could indeed destroy them.
+ */
+ bt_object_put_ref(downstream_port);
+ bt_object_put_ref(upstream_port);
+
+ /*
+ * Because this connection is ended, finalize each message
+ * iterator created from it.
+ *
+ * In practice, this only happens when the connection is
+ * destroyed and not all its message iterators were finalized,
+ * which is on graph destruction.
+ */
+ for (i = 0; i < conn->iterators->len; i++) {
+ struct bt_self_component_port_input_message_iterator *iterator =
+ g_ptr_array_index(conn->iterators, i);
+
+ BT_LIB_LOGD("Finalizing message iterator created by "
+ "this ended connection: %![iter-]+i", iterator);
+ bt_self_component_port_input_message_iterator_try_finalize(
+ iterator);
+
+ /*
+ * Make sure this iterator does not try to remove itself
+ * from this connection's iterators on destruction
+ * because this connection won't exist anymore.
+ */
+ bt_self_component_port_input_message_iterator_set_connection(
+ iterator, NULL);
+ }
+
+ g_ptr_array_set_size(conn->iterators, 0);
+
+ if (try_remove_from_graph) {
+ try_remove_connection_from_graph(conn);
+ }
+}
+
+const struct bt_port_output *bt_connection_borrow_upstream_port_const(
+ const struct bt_connection *connection)
+{
+ BT_ASSERT_PRE_NON_NULL(connection, "Connection");
+ return (void *) connection->upstream_port;
+}
+
+const struct bt_port_input *bt_connection_borrow_downstream_port_const(
+ const struct bt_connection *connection)
+{
+ BT_ASSERT_PRE_NON_NULL(connection, "Connection");
+ return (void *) connection->downstream_port;
+}
+
+BT_HIDDEN
+void bt_connection_remove_iterator(struct bt_connection *conn,
+ struct bt_self_component_port_input_message_iterator *iterator)
+{
+ g_ptr_array_remove(conn->iterators, iterator);
+ BT_LIB_LOGV("Removed message iterator from connection: "
+ "%![conn-]+x, %![iter-]+i", conn, iterator);
+ try_remove_connection_from_graph(conn);
+}
+
+void bt_connection_get_ref(const struct bt_connection *connection)
+{
+ bt_object_get_ref(connection);
+}
+
+void bt_connection_put_ref(const struct bt_connection *connection)
+{
+ bt_object_put_ref(connection);
+}
projects / babeltrace.git / blobdiff