/*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <folly/synchronization/HazptrThreadPoolExecutor.h>

#include <folly/Singleton.h>
#include <folly/executors/CPUThreadPoolExecutor.h>

namespace {

struct HazptrTPETag {};
folly::Singleton<folly::CPUThreadPoolExecutor, HazptrTPETag> hazptr_tpe_([] {
  return new folly::CPUThreadPoolExecutor(1);
});

folly::Executor* get_hazptr_tpe() {
  auto ex = hazptr_tpe_.try_get();
  return ex ? ex.get() : nullptr;
}

} // namespace

namespace folly {

void enable_hazptr_thread_pool_executor() {
  if (FLAGS_folly_hazptr_use_executor) {
    default_hazptr_domain().set_executor(&get_hazptr_tpe);
  }
}

} // namespace folly