text: /**
   *    Copyright (C) 2021-present MongoDB, Inc.
   *
   *    This program is free software: you can redistribute it and/or modify
   *    it under the terms of the Server Side Public License, version 1,
   *    as published by MongoDB, Inc.
   *
   *    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
   *    Server Side Public License for more details.
   *
   *    You should have received a copy of the Server Side Public License
   *    along with this program. If not, see
   *    <http://www.mongodb.com/licensing/server-side-public-license>.
   *
   *    As a special exception, the copyright holders give permission to link the
   *    code of portions of this program with the OpenSSL library under certain
   *    conditions as described in each individual source file and distribute
   *    linked combinations including the program with the OpenSSL library. You
   *    must comply with the Server Side Public License in all respects for
   *    all of the code used other than as permitted herein. If you modify file(s)
   *    with this exception, you may extend this exception to your version of the
   *    file(s), but you are not obligated to do so. If you do not wish to do so,
   *    delete this exception statement from your version. If you delete this
   *    exception statement from all source files in the program, then also delete
   *    it in the license file.
   */
  
  #pragma once
  
  #include "mongo/db/service_context.h"
  #include "mongo/s/concurrency/locker_mongos.h"
  
  namespace mongo {
  
  /**
   * ServiceContext hook that ensures OperationContexts are created with a valid
   * Locker instance. Intended for use in mongos.
   */
  class LockerMongosClientObserver : public ServiceContext::ClientObserver {
  public:
      LockerMongosClientObserver() = default;
      ~LockerMongosClientObserver() = default;
  
      void onCreateClient(Client* client) final {}
  
      void onDestroyClient(Client* client) final {}
  
      void onCreateOperationContext(OperationContext* opCtx) final {
          opCtx->setLockState(std::make_unique<LockerMongos>());
      }
  
      void onDestroyOperationContext(OperationContext* opCtx) final {}
  };
  
  }  // namespace mongo
  