4 * Babeltrace Plugin Component Graph
6 * Copyright 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
8 * Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
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:
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
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
29 #include <babeltrace/component/component-internal.h>
30 #include <babeltrace/component/graph-internal.h>
31 #include <babeltrace/component/connection-internal.h>
32 #include <babeltrace/component/component-sink-internal.h>
33 #include <babeltrace/component/component-source.h>
34 #include <babeltrace/component/component-filter.h>
35 #include <babeltrace/component/port.h>
36 #include <babeltrace/compiler.h>
40 void bt_graph_destroy(struct bt_object
*obj
)
42 struct bt_graph
*graph
= container_of(obj
,
43 struct bt_graph
, base
);
45 if (graph
->components
) {
46 g_ptr_array_free(graph
->components
, TRUE
);
48 if (graph
->connections
) {
49 g_ptr_array_free(graph
->connections
, TRUE
);
51 if (graph
->sinks_to_consume
) {
52 g_queue_free(graph
->sinks_to_consume
);
57 struct bt_graph
*bt_graph_create(void)
59 struct bt_graph
*graph
;
61 graph
= g_new0(struct bt_graph
, 1);
66 bt_object_init(graph
, bt_graph_destroy
);
68 graph
->connections
= g_ptr_array_new_with_free_func(bt_object_release
);
69 if (!graph
->connections
) {
72 graph
->components
= g_ptr_array_new_with_free_func(bt_object_release
);
73 if (!graph
->components
) {
76 graph
->sinks_to_consume
= g_queue_new();
77 if (!graph
->sinks_to_consume
) {
87 struct bt_connection
*bt_graph_connect(struct bt_graph
*graph
,
88 struct bt_port
*upstream_port
,
89 struct bt_port
*downstream_port
)
91 struct bt_connection
*connection
= NULL
;
92 struct bt_graph
*upstream_graph
= NULL
;
93 struct bt_graph
*downstream_graph
= NULL
;
94 struct bt_component
*upstream_component
= NULL
;
95 struct bt_component
*downstream_component
= NULL
;
96 enum bt_component_status component_status
;
97 bool upstream_was_already_in_graph
;
98 bool downstream_was_already_in_graph
;
99 int components_to_remove
= 0;
102 if (!graph
|| !upstream_port
|| !downstream_port
) {
106 if (bt_port_get_type(upstream_port
) != BT_PORT_TYPE_OUTPUT
) {
109 if (bt_port_get_type(downstream_port
) != BT_PORT_TYPE_INPUT
) {
113 /* Ensure the components are not already part of another graph. */
114 upstream_component
= bt_port_get_component(upstream_port
);
115 assert(upstream_component
);
116 upstream_graph
= bt_component_get_graph(upstream_component
);
117 if (upstream_graph
&& (graph
!= upstream_graph
)) {
118 fprintf(stderr
, "Upstream component is already part of another graph\n");
121 upstream_was_already_in_graph
= (graph
== upstream_graph
);
123 downstream_component
= bt_port_get_component(downstream_port
);
124 assert(downstream_component
);
125 downstream_graph
= bt_component_get_graph(downstream_component
);
126 if (downstream_graph
&& (graph
!= downstream_graph
)) {
127 fprintf(stderr
, "Downstream component is already part of another graph\n");
130 downstream_was_already_in_graph
= (graph
== downstream_graph
);
132 connection
= bt_connection_create(graph
, upstream_port
,
139 * Ownership of up/downstream_component and of the connection object is
140 * transferred to the graph.
142 g_ptr_array_add(graph
->connections
, connection
);
144 if (!upstream_was_already_in_graph
) {
145 g_ptr_array_add(graph
->components
, upstream_component
);
146 bt_component_set_graph(upstream_component
, graph
);
148 if (!downstream_was_already_in_graph
) {
149 g_ptr_array_add(graph
->components
, downstream_component
);
150 bt_component_set_graph(downstream_component
, graph
);
151 if (bt_component_get_class_type(downstream_component
) ==
152 BT_COMPONENT_CLASS_TYPE_SINK
) {
153 g_queue_push_tail(graph
->sinks_to_consume
,
154 downstream_component
);
159 * The graph is now the parent of these components which garantees their
160 * existence for the duration of the graph's lifetime.
164 * The components and connection are added to the graph before invoking
165 * the new_connection method in order to make them visible to the
166 * components during the method's invocation.
168 component_status
= bt_component_new_connection(upstream_component
,
169 upstream_port
, connection
);
170 if (component_status
!= BT_COMPONENT_STATUS_OK
) {
173 component_status
= bt_component_new_connection(downstream_component
,
174 downstream_port
, connection
);
175 if (component_status
!= BT_COMPONENT_STATUS_OK
) {
179 bt_put(upstream_graph
);
180 bt_put(downstream_graph
);
181 bt_put(upstream_component
);
182 bt_put(downstream_component
);
186 * Remove newly-added components from the graph, being careful
187 * not to remove a component that was already present in the graph
188 * and is connected to other components.
190 components_to_remove
+= upstream_was_already_in_graph
? 0 : 1;
191 components_to_remove
+= downstream_was_already_in_graph
? 0 : 1;
193 if (!downstream_was_already_in_graph
) {
194 if (bt_component_get_class_type(downstream_component
) ==
195 BT_COMPONENT_CLASS_TYPE_SINK
) {
196 g_queue_pop_tail(graph
->sinks_to_consume
);
199 /* Remove newly created connection. */
200 g_ptr_array_set_size(graph
->connections
,
201 graph
->connections
->len
- 1);
204 * Remove newly added components.
206 * Note that this is a tricky situation. The graph, being the parent
207 * of the components, does not hold a reference to them. Normally,
208 * components are destroyed right away when the graph is released since
209 * the graph, being their parent, bounds their lifetime
210 * (see doc/ref-counting.md).
212 * In this particular case, we must take a number of steps:
213 * 1) unset the components' parent to rollback the initial state of
214 * the components being connected.
215 * Note that the reference taken by the component on its graph is
216 * released by the set_parent call.
217 * 2) set the pointer in the components array to NULL so that the
218 * destruction function called on the array's resize in invoked on
221 * NOTE: Point #1 assumes that *something* holds a reference to both
222 * components being connected. The fact that a reference is being
223 * held to a component means that it must hold a reference to its
224 * parent to prevent the parent from being destroyed (again, refer
225 * to doc/red-counting.md). This reference to a component is
226 * most likely being held *transitively* by the caller which holds
227 * a reference to both ports (a port has its component as a
230 * This assumes that a graph is not connecting components by
231 * itself while not holding a reference to the ports/components
232 * being connected (i.e. "cheating" by using internal APIs).
234 for (i
= 0; i
< components_to_remove
; i
++) {
235 struct bt_component
*component
= g_ptr_array_index(
236 graph
->components
, graph
->components
->len
- 1);
238 bt_component_set_graph(component
, NULL
);
239 g_ptr_array_index(graph
->components
,
240 graph
->components
->len
- 1) = NULL
;
241 g_ptr_array_set_size(graph
->components
,
242 graph
->components
->len
- 1);
244 /* NOTE: Resizing the ptr_arrays invokes the destruction of the elements. */
247 BT_PUT(upstream_component
);
248 BT_PUT(downstream_component
);
253 enum bt_component_status
get_component_port_counts(
254 struct bt_component
*component
, uint64_t *input_count
,
255 uint64_t *output_count
)
257 enum bt_component_status ret
;
259 switch (bt_component_get_class_type(component
)) {
260 case BT_COMPONENT_CLASS_TYPE_SOURCE
:
261 ret
= bt_component_source_get_output_port_count(component
,
263 if (ret
!= BT_COMPONENT_STATUS_OK
) {
267 case BT_COMPONENT_CLASS_TYPE_FILTER
:
268 ret
= bt_component_filter_get_output_port_count(component
,
270 if (ret
!= BT_COMPONENT_STATUS_OK
) {
273 ret
= bt_component_filter_get_input_port_count(component
,
275 if (ret
!= BT_COMPONENT_STATUS_OK
) {
279 case BT_COMPONENT_CLASS_TYPE_SINK
:
280 ret
= bt_component_sink_get_input_port_count(component
,
282 if (ret
!= BT_COMPONENT_STATUS_OK
) {
290 ret
= BT_COMPONENT_STATUS_OK
;
296 struct bt_port
*get_input_port(struct bt_component
*component
, int index
)
298 struct bt_port
*port
= NULL
;
300 switch (bt_component_get_class_type(component
)) {
301 case BT_COMPONENT_CLASS_TYPE_FILTER
:
302 port
= bt_component_filter_get_input_port_at_index(component
,
305 case BT_COMPONENT_CLASS_TYPE_SINK
:
306 port
= bt_component_sink_get_input_port_at_index(component
,
316 struct bt_port
*get_output_port(struct bt_component
*component
, int index
)
318 struct bt_port
*port
= NULL
;
320 switch (bt_component_get_class_type(component
)) {
321 case BT_COMPONENT_CLASS_TYPE_SOURCE
:
322 port
= bt_component_source_get_output_port_at_index(component
,
325 case BT_COMPONENT_CLASS_TYPE_FILTER
:
326 port
= bt_component_filter_get_output_port_at_index(component
,
335 enum bt_graph_status
bt_graph_add_component_as_sibling(struct bt_graph
*graph
,
336 struct bt_component
*origin
,
337 struct bt_component
*new_component
)
339 uint64_t origin_input_port_count
= 0;
340 uint64_t origin_output_port_count
= 0;
341 uint64_t new_input_port_count
= 0;
342 uint64_t new_output_port_count
= 0;
343 enum bt_graph_status status
= BT_GRAPH_STATUS_OK
;
344 struct bt_graph
*origin_graph
= NULL
;
345 struct bt_graph
*new_graph
= NULL
;
346 struct bt_port
*origin_port
= NULL
;
347 struct bt_port
*new_port
= NULL
;
348 struct bt_port
*upstream_port
= NULL
;
349 struct bt_port
*downstream_port
= NULL
;
350 struct bt_connection
*origin_connection
= NULL
;
351 struct bt_connection
*new_connection
= NULL
;
354 if (!graph
|| !origin
|| !new_component
) {
355 status
= BT_GRAPH_STATUS_INVALID
;
359 if (bt_component_get_class_type(origin
) !=
360 bt_component_get_class_type(new_component
)) {
361 status
= BT_GRAPH_STATUS_INVALID
;
365 origin_graph
= bt_component_get_graph(origin
);
366 if (!origin_graph
|| (origin_graph
!= graph
)) {
367 status
= BT_GRAPH_STATUS_INVALID
;
371 new_graph
= bt_component_get_graph(new_component
);
373 status
= BT_GRAPH_STATUS_ALREADY_IN_A_GRAPH
;
377 if (get_component_port_counts(origin
, &origin_input_port_count
,
378 &origin_output_port_count
) != BT_COMPONENT_STATUS_OK
) {
379 status
= BT_GRAPH_STATUS_INVALID
;
382 if (get_component_port_counts(new_component
, &new_input_port_count
,
383 &new_output_port_count
) != BT_COMPONENT_STATUS_OK
) {
384 status
= BT_GRAPH_STATUS_INVALID
;
388 if (origin_input_port_count
!= new_input_port_count
||
389 origin_output_port_count
!= new_output_port_count
) {
390 status
= BT_GRAPH_STATUS_INVALID
;
394 /* Replicate input connections. */
395 for (port_index
= 0; port_index
< origin_input_port_count
; port_index
++) {
396 uint64_t connection_count
, connection_index
;
398 origin_port
= get_input_port(origin
, port_index
);
400 status
= BT_GRAPH_STATUS_ERROR
;
401 goto error_disconnect
;
403 new_port
= get_input_port(new_component
, port_index
);
405 status
= BT_GRAPH_STATUS_ERROR
;
406 goto error_disconnect
;
409 if (bt_port_get_connection_count(origin_port
, &connection_count
) !=
411 status
= BT_GRAPH_STATUS_ERROR
;
412 goto error_disconnect
;
415 for (connection_index
= 0; connection_index
< connection_count
;
416 connection_index
++) {
417 origin_connection
= bt_port_get_connection(origin_port
,
419 if (!origin_connection
) {
420 goto error_disconnect
;
423 upstream_port
= bt_connection_get_output_port(
425 if (!upstream_port
) {
426 goto error_disconnect
;
429 new_connection
= bt_graph_connect(graph
, upstream_port
,
431 if (!new_connection
) {
432 goto error_disconnect
;
435 BT_PUT(upstream_port
);
436 BT_PUT(origin_connection
);
437 BT_PUT(new_connection
);
443 /* Replicate output connections. */
444 for (port_index
= 0; port_index
< origin_output_port_count
; port_index
++) {
445 uint64_t connection_count
, connection_index
;
447 origin_port
= get_output_port(origin
, port_index
);
449 status
= BT_GRAPH_STATUS_ERROR
;
450 goto error_disconnect
;
452 new_port
= get_output_port(new_component
, port_index
);
454 status
= BT_GRAPH_STATUS_ERROR
;
455 goto error_disconnect
;
458 if (bt_port_get_connection_count(origin_port
, &connection_count
) !=
460 status
= BT_GRAPH_STATUS_ERROR
;
461 goto error_disconnect
;
464 for (connection_index
= 0; connection_index
< connection_count
;
465 connection_index
++) {
466 origin_connection
= bt_port_get_connection(origin_port
,
468 if (!origin_connection
) {
469 goto error_disconnect
;
472 downstream_port
= bt_connection_get_input_port(
474 if (!downstream_port
) {
475 goto error_disconnect
;
478 new_connection
= bt_graph_connect(graph
, new_port
,
480 if (!new_connection
) {
481 goto error_disconnect
;
484 BT_PUT(downstream_port
);
485 BT_PUT(origin_connection
);
486 BT_PUT(new_connection
);
492 bt_put(origin_graph
);
496 bt_put(upstream_port
);
497 bt_put(downstream_port
);
498 bt_put(origin_connection
);
499 bt_put(new_connection
);
502 /* Destroy all connections of the new component. */
507 enum bt_component_status
bt_graph_consume(struct bt_graph
*graph
)
509 struct bt_component
*sink
;
510 enum bt_component_status status
;
514 status
= BT_COMPONENT_STATUS_INVALID
;
518 if (g_queue_is_empty(graph
->sinks_to_consume
)) {
519 status
= BT_COMPONENT_STATUS_END
;
523 current_node
= g_queue_pop_head_link(graph
->sinks_to_consume
);
524 sink
= current_node
->data
;
525 status
= bt_component_sink_consume(sink
);
526 if (status
!= BT_COMPONENT_STATUS_END
) {
527 g_queue_push_tail_link(graph
->sinks_to_consume
, current_node
);
531 /* End reached, the node is not added back to the queue and free'd. */
532 g_queue_delete_link(graph
->sinks_to_consume
, current_node
);
534 /* Don't forward an END status if there are sinks left to consume. */
535 if (!g_queue_is_empty(graph
->sinks_to_consume
)) {
536 status
= BT_GRAPH_STATUS_OK
;
543 enum bt_graph_status
bt_graph_run(struct bt_graph
*graph
,
544 enum bt_component_status
*_component_status
)
546 enum bt_component_status component_status
;
547 enum bt_graph_status graph_status
= BT_GRAPH_STATUS_OK
;
550 graph_status
= BT_GRAPH_STATUS_INVALID
;
555 component_status
= bt_graph_consume(graph
);
556 if (component_status
== BT_COMPONENT_STATUS_AGAIN
) {
558 * If AGAIN is received and there are multiple sinks,
559 * go ahead and consume from the next sink.
561 * However, in the case where a single sink is left,
562 * the caller can decide to busy-wait and call
563 * bt_graph_run continuously until the source is ready
564 * or it can decide to sleep for an arbitrary amount of
567 if (graph
->sinks_to_consume
->length
> 1) {
568 component_status
= BT_COMPONENT_STATUS_OK
;
571 } while (component_status
== BT_COMPONENT_STATUS_OK
);
573 if (_component_status
) {
574 *_component_status
= component_status
;
577 if (g_queue_is_empty(graph
->sinks_to_consume
)) {
578 graph_status
= BT_GRAPH_STATUS_END
;
579 } else if (component_status
== BT_COMPONENT_STATUS_AGAIN
) {
580 graph_status
= BT_GRAPH_STATUS_AGAIN
;
582 graph_status
= BT_GRAPH_STATUS_ERROR
;