Function FindOrCreateBackwardPassScope

oneflow/core/framework/scope_util.cpp:136–151

extern const std::string kBackwardPass;
Maybe<Scope> FindOrCreateBackwardPassScope(const std::shared_ptr<Scope>& scope) {
  auto* storage = BackwardPassScopeStorage::Global();
  auto& scopes = storage->get();
  std::lock_guard<std::mutex> lock(storage->mutex);
  auto it = scopes.find(JUST(scope->symbol_id()));
  if (it != scopes.end()) { return it->second; }
  auto scope_proto = JUST((scope->MakeChildScopeProto()));
  scope_proto->set_calculation_pass_name(kBackwardPass);
  std::shared_ptr<Scope> backward_pass_scope;
  JUST(PhysicalRun([&](InstructionsBuilder* builder) -> Maybe<void> {
    backward_pass_scope = JUST(builder->GetScopeSymbol(*scope_proto));
    return Maybe<void>::Ok();
  }));
  scopes.emplace(JUST(scope->symbol_id()), backward_pass_scope);
  return backward_pass_scope;
}

void ClearAllBackwardPassScope() {
  auto* storage = BackwardPassScopeStorage::Global();