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blender-archive/source/blender/depsgraph/intern/builder/deg_builder_cycle.cc

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/*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* The Original Code is Copyright (C) 2015 Blender Foundation.
* All rights reserved.
*
* Contributor(s): Sergey Sharybin
*
* ***** END GPL LICENSE BLOCK *****
*/
/** \file blender/depsgraph/intern/builder/deg_builder_cycle.cc
* \ingroup depsgraph
*/
#include "intern/builder/deg_builder_cycle.h"
// TOO(sergey): Use some wrappers over those?
#include <cstdio>
#include <cstdlib>
#include "BLI_utildefines.h"
#include "BLI_stack.h"
#include "util/deg_util_foreach.h"
#include "intern/nodes/deg_node.h"
#include "intern/nodes/deg_node_component.h"
#include "intern/nodes/deg_node_operation.h"
#include "intern/depsgraph.h"
namespace DEG {
void deg_graph_detect_cycles(Depsgraph *graph)
{
enum {
/* Not is not visited at all during traversal. */
NODE_NOT_VISITED = 0,
/* Node has been visited during traversal and not in current stack. */
NODE_VISITED = 1,
/* Node has been visited during traversal and is in current stack. */
NODE_IN_STACK = 2,
};
struct StackEntry {
OperationDepsNode *node;
StackEntry *from;
DepsRelation *via_relation;
};
BLI_Stack *traversal_stack = BLI_stack_new(sizeof(StackEntry),
"DEG detect cycles stack");
foreach (OperationDepsNode *node, graph->operations) {
bool has_inlinks = false;
foreach (DepsRelation *rel, node->inlinks) {
if (rel->from->type == DEG_NODE_TYPE_OPERATION) {
has_inlinks = true;
}
}
if (has_inlinks == false) {
StackEntry entry;
entry.node = node;
entry.from = NULL;
entry.via_relation = NULL;
BLI_stack_push(traversal_stack, &entry);
node->tag = NODE_IN_STACK;
}
else {
node->tag = NODE_NOT_VISITED;
}
node->done = 0;
}
while (!BLI_stack_is_empty(traversal_stack)) {
StackEntry *entry = (StackEntry *)BLI_stack_peek(traversal_stack);
OperationDepsNode *node = entry->node;
bool all_child_traversed = true;
for (int i = node->done; i < node->outlinks.size(); ++i) {
DepsRelation *rel = node->outlinks[i];
if (rel->to->type == DEG_NODE_TYPE_OPERATION) {
OperationDepsNode *to = (OperationDepsNode *)rel->to;
if (to->tag == NODE_IN_STACK) {
printf("Dependency cycle detected:\n");
printf(" '%s' depends on '%s' through '%s'\n",
to->full_identifier().c_str(),
node->full_identifier().c_str(),
rel->name);
StackEntry *current = entry;
while (current->node != to) {
BLI_assert(current != NULL);
printf(" '%s' depends on '%s' through '%s'\n",
current->node->full_identifier().c_str(),
current->from->node->full_identifier().c_str(),
current->via_relation->name);
current = current->from;
}
/* TODO(sergey): So called russian roulette cycle solver. */
rel->flag |= DEPSREL_FLAG_CYCLIC;
}
else if (to->tag == NODE_NOT_VISITED) {
StackEntry new_entry;
new_entry.node = to;
new_entry.from = entry;
new_entry.via_relation = rel;
BLI_stack_push(traversal_stack, &new_entry);
to->tag = NODE_IN_STACK;
all_child_traversed = false;
node->done = i;
break;
}
}
}
if (all_child_traversed) {
node->tag = NODE_VISITED;
BLI_stack_discard(traversal_stack);
}
}
BLI_stack_free(traversal_stack);
}
} // namespace DEG