depsgraph_registry.cc

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/* SPDX-FileCopyrightText: 2019 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#include <memory>
#include <mutex>
 
#include "intern/depsgraph_registry.hh"
 
#include "BLI_utildefines.h"
 
#include "intern/depsgraph.hh"
 
namespace blender::deg {
 
/* Global registry for dependency graphs associated with a main database.
 *
 * Threads may add or remove depsgraphs for different mains concurrently
 * (for example for preview rendering), but not the same main. */
 
/* Use pointer for map value to ensure span returned by get_all_registered_graphs
 * remains unchanged as other mains are added or removed. */
using GraphSetPtr = std::unique_ptr<VectorSet<Depsgraph *>>;
struct GraphRegistry {
  Map<Main *, GraphSetPtr> map;
  std::mutex mutex;
};
 
static GraphRegistry &get_graph_registry()
{
  static GraphRegistry graph_registry;
  return graph_registry;
}
 
void register_graph(Depsgraph *depsgraph)
{
  GraphRegistry &graph_registry = get_graph_registry();
  Main *bmain = depsgraph->bmain;
 
  std::lock_guard<std::mutex> lock{graph_registry.mutex};
  graph_registry.map
      .lookup_or_add_cb(bmain, []() { return std::make_unique<VectorSet<Depsgraph *>>(); })
      ->add_new(depsgraph);
}
 
void unregister_graph(Depsgraph *depsgraph)
{
  Main *bmain = depsgraph->bmain;
  GraphRegistry &graph_registry = get_graph_registry();
 
  std::lock_guard<std::mutex> lock{graph_registry.mutex};
  GraphSetPtr &graphs = graph_registry.map.lookup(bmain);
  graphs->remove(depsgraph);
 
  /* If this was the last depsgraph associated with the main, remove the main entry as well. */
  if (graphs->is_empty()) {
    graph_registry.map.remove(bmain);
  }
}
 
Span<Depsgraph *> get_all_registered_graphs(Main *bmain)
{
  GraphRegistry &graph_registry = get_graph_registry();
  std::lock_guard<std::mutex> lock{graph_registry.mutex};
  GraphSetPtr *graphs = graph_registry.map.lookup_ptr(bmain);
  if (graphs) {
    return **graphs;
  }
  return {};
}
 
}  // namespace blender::deg