text: /**
   *    Copyright (C) 2020-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/namespace_string.h"
  #include "mongo/db/operation_context.h"
  #include "mongo/db/repl/replica_set_aware_service.h"
  #include "mongo/db/service_context.h"
  #include "mongo/db/write_concern_options.h"
  
  namespace mongo {
  
  namespace recoverable_critical_section_util {
  
  bool inRecoveryMode(OperationContext* opCtx);
  
  }
  
  class RecoverableCriticalSectionService
      : public ReplicaSetAwareServiceShardSvr<RecoverableCriticalSectionService> {
  
  public:
      RecoverableCriticalSectionService() = default;
  
      static RecoverableCriticalSectionService* get(ServiceContext* serviceContext);
      static RecoverableCriticalSectionService* get(OperationContext* opCtx);
  
      /**
       * Acquires the collection critical section in the catch-up phase (i.e. blocking writes) for the
       * specified namespace and reason. It works even if the namespace's current metadata are
       * UNKNOWN.
       *
       * It adds a doc to config.collectionCriticalSections with with writeConcern write concern.
       *
       * Do nothing if the collection critical section is taken for that nss and reason, and will
       * invariant otherwise since it is the responsibility of the caller to ensure that only one
       * thread is taking the critical section.
       */
      void acquireRecoverableCriticalSectionBlockWrites(
          OperationContext* opCtx,
          const NamespaceString& nss,
          const BSONObj& reason,
          const WriteConcernOptions& writeConcern,
          const boost::optional<BSONObj>& additionalInfo = boost::none);
  
      /**
       * Advances the recoverable critical section from the catch-up phase (i.e. blocking writes) to
       * the commit phase (i.e. blocking reads) for the specified nss and reason. The recoverable
       * critical section must have been acquired first through
       * 'acquireRecoverableCriticalSectionBlockWrites' function.
       *
       * It updates a doc from config.collectionCriticalSections with writeConcern write concern.
       *
       * Do nothing if the collection critical section is already taken in commit phase.
       */
      void promoteRecoverableCriticalSectionToBlockAlsoReads(OperationContext* opCtx,
                                                             const NamespaceString& nss,
                                                             const BSONObj& reason,
                                                             const WriteConcernOptions& writeConcern);
      /**
       * Releases the recoverable critical section for the given nss and reason.
       *
       * It removes a doc from config.collectionCriticalSections with writeConcern write concern.
       *
       * Do nothing if the collection critical section is not taken for that nss and reason.
       */
      void releaseRecoverableCriticalSection(OperationContext* opCtx,
                                             const NamespaceString& nss,
                                             const BSONObj& reason,
                                             const WriteConcernOptions& writeConcern);
  
  
      /**
       * This method is called when we have to mirror the state on disk of the recoverable critical
       * section to memory (on startUp or on rollback).
       */
      void recoverRecoverableCriticalSections(OperationContext* opCtx);
  
  private:
      void onInitialDataAvailable(OperationContext* opCtx,
                                  bool isMajorityDataAvailable) override final {
          recoverRecoverableCriticalSections(opCtx);
      }
  
      void onStartup(OperationContext* opCtx) override final {}
      void onShutdown() override final {}
      void onStepUpBegin(OperationContext* opCtx, long long term) override final {}
      void onStepUpComplete(OperationContext* opCtx, long long term) override final {}
      void onStepDown() override final {}
      void onBecomeArbiter() override final {}
  };
  
  }  // namespace mongo
  