| 1 | /* |
| 2 | * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com> |
| 3 | * Copyright 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 4 | * |
| 5 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 6 | * of this software and associated documentation files (the "Software"), to deal |
| 7 | * in the Software without restriction, including without limitation the rights |
| 8 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 9 | * copies of the Software, and to permit persons to whom the Software is |
| 10 | * furnished to do so, subject to the following conditions: |
| 11 | * |
| 12 | * The above copyright notice and this permission notice shall be included in |
| 13 | * all copies or substantial portions of the Software. |
| 14 | * |
| 15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 18 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 19 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 20 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| 21 | * SOFTWARE. |
| 22 | */ |
| 23 | |
| 24 | #define BT_LOG_TAG "LIB/CONNECTION" |
| 25 | #include "lib/logging.h" |
| 26 | |
| 27 | #include "common/assert.h" |
| 28 | #include "lib/assert-pre.h" |
| 29 | #include "lib/assert-post.h" |
| 30 | #include <babeltrace2/graph/connection-const.h> |
| 31 | #include "lib/object.h" |
| 32 | #include "compat/compiler.h" |
| 33 | #include <stdlib.h> |
| 34 | #include <glib.h> |
| 35 | |
| 36 | #include "component.h" |
| 37 | #include "connection.h" |
| 38 | #include "graph.h" |
| 39 | #include "message/iterator.h" |
| 40 | #include "port.h" |
| 41 | |
| 42 | static |
| 43 | void destroy_connection(struct bt_object *obj) |
| 44 | { |
| 45 | struct bt_connection *connection = container_of(obj, |
| 46 | struct bt_connection, base); |
| 47 | |
| 48 | BT_LIB_LOGI("Destroying connection: %!+x", connection); |
| 49 | |
| 50 | /* |
| 51 | * Make sure that each message iterator which was created for |
| 52 | * this connection is finalized before we destroy it. Once a |
| 53 | * message iterator is finalized, all its method return NULL or |
| 54 | * the BT_MESSAGE_ITERATOR_STATUS_CANCELED status. |
| 55 | * |
| 56 | * Because connections are destroyed before components within a |
| 57 | * graph, this ensures that message iterators are always |
| 58 | * finalized before their upstream component. |
| 59 | * |
| 60 | * Ending the connection does exactly this. We pass `false` to |
| 61 | * bt_connection_end() here to avoid removing this connection |
| 62 | * from the graph: if we're here, we're already in the graph's |
| 63 | * destructor. |
| 64 | */ |
| 65 | bt_connection_end(connection, false); |
| 66 | g_ptr_array_free(connection->iterators, TRUE); |
| 67 | connection->iterators = NULL; |
| 68 | |
| 69 | /* |
| 70 | * No bt_object_put_ref on ports as a connection only holds _weak_ |
| 71 | * references to them. |
| 72 | */ |
| 73 | g_free(connection); |
| 74 | } |
| 75 | |
| 76 | static |
| 77 | void try_remove_connection_from_graph(struct bt_connection *connection) |
| 78 | { |
| 79 | void *graph = (void *) bt_object_borrow_parent(&connection->base); |
| 80 | |
| 81 | if (connection->base.ref_count > 0 || |
| 82 | connection->downstream_port || |
| 83 | connection->upstream_port || |
| 84 | connection->iterators->len > 0) { |
| 85 | return; |
| 86 | } |
| 87 | |
| 88 | /* |
| 89 | * At this point we know that: |
| 90 | * |
| 91 | * 1. The connection is ended (ports were disconnected). |
| 92 | * 2. All the message iterators that this connection |
| 93 | * created, if any, are finalized. |
| 94 | * 3. The connection's reference count is 0, so only the |
| 95 | * parent (graph) owns this connection after this call. |
| 96 | * |
| 97 | * In other words, no other object than the graph knows this |
| 98 | * connection. |
| 99 | * |
| 100 | * It is safe to remove the connection from the graph, therefore |
| 101 | * destroying it. |
| 102 | */ |
| 103 | BT_LIB_LOGD("Removing self from graph's connections: " |
| 104 | "%![graph-]+g, %![conn-]+x", graph, connection); |
| 105 | bt_graph_remove_connection(graph, connection); |
| 106 | } |
| 107 | |
| 108 | static |
| 109 | void parent_is_owner(struct bt_object *obj) |
| 110 | { |
| 111 | struct bt_connection *connection = container_of(obj, |
| 112 | struct bt_connection, base); |
| 113 | |
| 114 | try_remove_connection_from_graph(connection); |
| 115 | } |
| 116 | |
| 117 | BT_HIDDEN |
| 118 | struct bt_connection *bt_connection_create(struct bt_graph *graph, |
| 119 | struct bt_port *upstream_port, |
| 120 | struct bt_port *downstream_port) |
| 121 | { |
| 122 | struct bt_connection *connection = NULL; |
| 123 | |
| 124 | BT_LIB_LOGI("Creating connection: " |
| 125 | "%![graph-]+g, %![up-port-]+p, %![down-port-]+p", |
| 126 | graph, upstream_port, downstream_port); |
| 127 | connection = g_new0(struct bt_connection, 1); |
| 128 | if (!connection) { |
| 129 | BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate one connection."); |
| 130 | goto end; |
| 131 | } |
| 132 | |
| 133 | bt_object_init_shared_with_parent(&connection->base, |
| 134 | destroy_connection); |
| 135 | bt_object_set_parent_is_owner_listener_func(&connection->base, |
| 136 | parent_is_owner); |
| 137 | connection->iterators = g_ptr_array_new(); |
| 138 | if (!connection->iterators) { |
| 139 | BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate a GPtrArray."); |
| 140 | BT_OBJECT_PUT_REF_AND_RESET(connection); |
| 141 | goto end; |
| 142 | } |
| 143 | |
| 144 | /* Weak references are taken, see comment in header. */ |
| 145 | connection->upstream_port = upstream_port; |
| 146 | connection->downstream_port = downstream_port; |
| 147 | BT_LIB_LOGD("Setting upstream port's connection: %!+p", upstream_port); |
| 148 | bt_port_set_connection(upstream_port, connection); |
| 149 | BT_LIB_LOGD("Setting downstream port's connection: %!+p", |
| 150 | downstream_port); |
| 151 | bt_port_set_connection(downstream_port, connection); |
| 152 | bt_object_set_parent(&connection->base, &graph->base); |
| 153 | BT_LIB_LOGI("Created connection: %!+x", connection); |
| 154 | |
| 155 | end: |
| 156 | return connection; |
| 157 | } |
| 158 | |
| 159 | BT_HIDDEN |
| 160 | void bt_connection_end(struct bt_connection *conn, bool try_remove_from_graph) |
| 161 | { |
| 162 | struct bt_port *downstream_port = conn->downstream_port; |
| 163 | struct bt_port *upstream_port = conn->upstream_port; |
| 164 | size_t i; |
| 165 | |
| 166 | BT_LIB_LOGI("Ending connection: %!+x, try-remove-from-graph=%d", |
| 167 | conn, try_remove_from_graph); |
| 168 | |
| 169 | /* |
| 170 | * Any of the following message callback functions could |
| 171 | * remove one of the connection's ports from its component. To |
| 172 | * make sure that at least logging in called functions works |
| 173 | * with existing objects, get a local reference on both ports. |
| 174 | */ |
| 175 | bt_object_get_ref(downstream_port); |
| 176 | bt_object_get_ref(upstream_port); |
| 177 | |
| 178 | if (downstream_port) { |
| 179 | BT_LIB_LOGD("Disconnecting connection's downstream port: %!+p", |
| 180 | downstream_port); |
| 181 | bt_port_set_connection(downstream_port, NULL); |
| 182 | conn->downstream_port = NULL; |
| 183 | } |
| 184 | |
| 185 | if (upstream_port) { |
| 186 | BT_LIB_LOGD("Disconnecting connection's upstream port: %!+p", |
| 187 | upstream_port); |
| 188 | bt_port_set_connection(upstream_port, NULL); |
| 189 | conn->upstream_port = NULL; |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * It is safe to put the local port references now that we don't |
| 194 | * need them anymore. This could indeed destroy them. |
| 195 | */ |
| 196 | bt_object_put_ref(downstream_port); |
| 197 | bt_object_put_ref(upstream_port); |
| 198 | |
| 199 | /* |
| 200 | * Because this connection is ended, finalize each message |
| 201 | * iterator created from it. |
| 202 | * |
| 203 | * In practice, this only happens when the connection is |
| 204 | * destroyed and not all its message iterators were finalized, |
| 205 | * which is on graph destruction. |
| 206 | */ |
| 207 | for (i = 0; i < conn->iterators->len; i++) { |
| 208 | struct bt_self_component_port_input_message_iterator *iterator = |
| 209 | g_ptr_array_index(conn->iterators, i); |
| 210 | |
| 211 | BT_LIB_LOGD("Finalizing message iterator created by " |
| 212 | "this ended connection: %![iter-]+i", iterator); |
| 213 | bt_self_component_port_input_message_iterator_try_finalize( |
| 214 | iterator); |
| 215 | |
| 216 | /* |
| 217 | * Make sure this iterator does not try to remove itself |
| 218 | * from this connection's iterators on destruction |
| 219 | * because this connection won't exist anymore. |
| 220 | */ |
| 221 | bt_self_component_port_input_message_iterator_set_connection( |
| 222 | iterator, NULL); |
| 223 | } |
| 224 | |
| 225 | g_ptr_array_set_size(conn->iterators, 0); |
| 226 | |
| 227 | if (try_remove_from_graph) { |
| 228 | try_remove_connection_from_graph(conn); |
| 229 | } |
| 230 | } |
| 231 | |
| 232 | const struct bt_port_output *bt_connection_borrow_upstream_port_const( |
| 233 | const struct bt_connection *connection) |
| 234 | { |
| 235 | BT_ASSERT_PRE_DEV_NON_NULL(connection, "Connection"); |
| 236 | return (void *) connection->upstream_port; |
| 237 | } |
| 238 | |
| 239 | const struct bt_port_input *bt_connection_borrow_downstream_port_const( |
| 240 | const struct bt_connection *connection) |
| 241 | { |
| 242 | BT_ASSERT_PRE_DEV_NON_NULL(connection, "Connection"); |
| 243 | return (void *) connection->downstream_port; |
| 244 | } |
| 245 | |
| 246 | BT_HIDDEN |
| 247 | void bt_connection_remove_iterator(struct bt_connection *conn, |
| 248 | struct bt_self_component_port_input_message_iterator *iterator) |
| 249 | { |
| 250 | g_ptr_array_remove(conn->iterators, iterator); |
| 251 | BT_LIB_LOGD("Removed message iterator from connection: " |
| 252 | "%![conn-]+x, %![iter-]+i", conn, iterator); |
| 253 | try_remove_connection_from_graph(conn); |
| 254 | } |
| 255 | |
| 256 | void bt_connection_get_ref(const struct bt_connection *connection) |
| 257 | { |
| 258 | bt_object_get_ref(connection); |
| 259 | } |
| 260 | |
| 261 | void bt_connection_put_ref(const struct bt_connection *connection) |
| 262 | { |
| 263 | bt_object_put_ref(connection); |
| 264 | } |