X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=lib%2Fgraph%2Fconnection.c;h=00b3a2a707ec3d4e4387aa8f0f5da9b8ab800853;hb=3fadfbc0c91f82c46bd36e6e0657ea93570c9db1;hp=bfc9c04b8f0b0831fd03a5a6cc47648a6713afa0;hpb=3230ee6b4f3a704958b761daecae835c56938bc9;p=babeltrace.git diff --git a/lib/graph/connection.c b/lib/graph/connection.c index bfc9c04b..00b3a2a7 100644 --- a/lib/graph/connection.c +++ b/lib/graph/connection.c @@ -1,12 +1,7 @@ /* - * connection.c - * - * Babeltrace Connection - * + * Copyright 2017-2018 Philippe Proulx * Copyright 2017 Jérémie Galarneau * - * Author: Jérémie Galarneau - * * 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 @@ -26,207 +21,242 @@ * SOFTWARE. */ -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include +#define BT_LOG_TAG "CONNECTION" +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include #include static -void bt_connection_destroy(struct bt_object *obj) +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); + /* - * No bt_put on ports as a connection only holds _weak_ references - * to them. + * 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); } -struct bt_connection *bt_connection_from_private_connection( - struct bt_private_connection *private_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) { - return bt_get(bt_connection_from_private(private_connection)); + 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_connection *bt_connection_create(struct bt_graph *graph, struct bt_port *upstream_port, struct bt_port *downstream_port) { struct bt_connection *connection = NULL; - if (bt_port_get_type(upstream_port) != BT_PORT_TYPE_OUTPUT) { - goto end; - } - if (bt_port_get_type(downstream_port) != BT_PORT_TYPE_INPUT) { + 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; } - connection = g_new0(struct bt_connection, 1); - if (!connection) { + 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; } - bt_object_init(connection, bt_connection_destroy); /* 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, &graph->base); + bt_object_set_parent(&connection->base, &graph->base); + BT_LIB_LOGD("Created connection: %!+x", connection); + end: return connection; } BT_HIDDEN -void bt_connection_disconnect_ports(struct bt_connection *conn) +void bt_connection_end(struct bt_connection *conn, bool try_remove_from_graph) { - struct bt_component *downstream_comp = NULL; - struct bt_component *upstream_comp = NULL; struct bt_port *downstream_port = conn->downstream_port; struct bt_port *upstream_port = conn->upstream_port; - struct bt_graph *graph = (void *) bt_object_get_parent(conn); + 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) { - downstream_comp = bt_port_get_component(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) { - upstream_comp = bt_port_get_component(upstream_port); + BT_LIB_LOGD("Disconnecting connection's upstream port: %!+p", + upstream_port); bt_port_set_connection(upstream_port, NULL); conn->upstream_port = NULL; } - if (downstream_comp) { - bt_component_port_disconnected(downstream_comp, - downstream_port); - } + /* + * 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); - if (upstream_comp) { - bt_component_port_disconnected(upstream_comp, upstream_port); + /* + * 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); } - assert(graph); - bt_graph_notify_ports_disconnected(graph, upstream_comp, - downstream_comp, upstream_port, downstream_port); - bt_put(downstream_comp); - bt_put(upstream_comp); - bt_put(graph); + g_ptr_array_set_size(conn->iterators, 0); + + if (try_remove_from_graph) { + try_remove_connection_from_graph(conn); + } } -struct bt_port *bt_connection_get_upstream_port( - struct bt_connection *connection) +const struct bt_port_output *bt_connection_borrow_upstream_port_const( + const struct bt_connection *connection) { - return connection ? bt_get(connection->upstream_port) : NULL; + BT_ASSERT_PRE_NON_NULL(connection, "Connection"); + return (void *) connection->upstream_port; } -struct bt_port *bt_connection_get_downstream_port( - struct bt_connection *connection) +const struct bt_port_input *bt_connection_borrow_downstream_port_const( + const struct bt_connection *connection) { - return connection ? bt_get(connection->downstream_port) : NULL; + BT_ASSERT_PRE_NON_NULL(connection, "Connection"); + return (void *) connection->downstream_port; } -struct bt_notification_iterator * -bt_private_connection_create_notification_iterator( - struct bt_private_connection *private_connection) +BT_HIDDEN +void bt_connection_remove_iterator(struct bt_connection *conn, + struct bt_self_component_port_input_message_iterator *iterator) { - enum bt_notification_iterator_status ret_iterator; - enum bt_component_class_type upstream_comp_class_type; - struct bt_notification_iterator *iterator = NULL; - struct bt_port *upstream_port = NULL; - struct bt_component *upstream_component = NULL; - struct bt_component_class *upstream_comp_class = NULL; - struct bt_connection *connection = NULL; - bt_component_class_notification_iterator_init_method init_method = NULL; - - if (!private_connection) { - goto error; - } - - connection = bt_connection_from_private(private_connection); - - if (!connection->upstream_port || !connection->downstream_port) { - goto error; - } - - upstream_port = connection->upstream_port; - assert(upstream_port); - upstream_component = bt_port_get_component(upstream_port); - assert(upstream_component); - upstream_comp_class = upstream_component->class; - - if (!upstream_component) { - goto error; - } - - upstream_comp_class_type = - bt_component_get_class_type(upstream_component); - if (upstream_comp_class_type != BT_COMPONENT_CLASS_TYPE_SOURCE && - upstream_comp_class_type != BT_COMPONENT_CLASS_TYPE_FILTER) { - /* Unsupported operation. */ - goto error; - } - - iterator = bt_notification_iterator_create(upstream_component, - upstream_port); - if (!iterator) { - goto error; - } - - switch (upstream_comp_class_type) { - case BT_COMPONENT_CLASS_TYPE_SOURCE: - { - struct bt_component_class_source *source_class = - container_of(upstream_comp_class, - struct bt_component_class_source, parent); - init_method = source_class->methods.iterator.init; - break; - } - case BT_COMPONENT_CLASS_TYPE_FILTER: - { - struct bt_component_class_filter *filter_class = - container_of(upstream_comp_class, - struct bt_component_class_filter, parent); - init_method = filter_class->methods.iterator.init; - break; - } - default: - /* Unreachable. */ - assert(0); - } - - if (init_method) { - enum bt_notification_iterator_status status = init_method( - bt_private_notification_iterator_from_notification_iterator(iterator), - bt_private_port_from_port(upstream_port)); - if (status < 0) { - goto error; - } - } - - ret_iterator = bt_notification_iterator_validate(iterator); - if (ret_iterator != BT_NOTIFICATION_ITERATOR_STATUS_OK) { - goto error; - } - - goto end; + 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); +} -error: - BT_PUT(iterator); +void bt_connection_get_ref(const struct bt_connection *connection) +{ + bt_object_get_ref(connection); +} -end: - bt_put(upstream_component); - return iterator; +void bt_connection_put_ref(const struct bt_connection *connection) +{ + bt_object_put_ref(connection); }