TransportClient.h

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/*
 *
 *
 * Distributed under the OpenDDS License.
 * See: http://www.opendds.org/license.html
 */

#ifndef OPENDDS_DCPS_TRANSPORT_CLIENT_H
#define OPENDDS_DCPS_TRANSPORT_CLIENT_H

#include "dds/DCPS/dcps_export.h"
#include "TransportConfig_rch.h"
#include "TransportImpl.h"
#include "DataLinkSet.h"

#include "dds/DCPS/AssociationData.h"
#include "dds/DCPS/ReactorInterceptor.h"
#include "dds/DCPS/Service_Participant.h"
#include "dds/DCPS/PoolAllocator.h"
#include "dds/DCPS/PoolAllocationBase.h"
#include "dds/DCPS/DiscoveryListener.h"

#include "ace/Time_Value.h"
#include "ace/Event_Handler.h"
#include "ace/Reverse_Lock_T.h"

// Forward definition of a test-friendly class in the global name space
class DDS_TEST;

namespace OpenDDS {
namespace DCPS {

class EntityImpl;
class TransportInst;
class AssocationInfo;
class ReaderIdSeq;
class WriterIdSeq;
class SendStateDataSampleList;
class SendStateDataSampleListIterator;

/**
 * @brief Mix-in class for DDS entities which directly use the transport layer.
 *
 * DataReaderImpl and DataWriterImpl are TransportClients.  The TransportClient
 * class manages the TransportImpl objects that represent the available
 * communication mechanisms and the DataLink objects that represent the
 * currently active communication channels to peers.
 */
class OpenDDS_Dcps_Export TransportClient {
public:
  // Used by TransportImpl to complete associate() processing:
  void use_datalink(const RepoId& remote_id, const DataLink_rch& link);

  // values for flags parameter of transport_assoc_done():
  enum { ASSOC_OK = 1, ASSOC_ACTIVE = 2 };

protected:
  TransportClient();
  virtual ~TransportClient();


  // Local setup:

  void enable_transport(bool reliable, bool durable);
  void enable_transport_using_config(bool reliable, bool durable,
                                     const TransportConfig_rch& tc);

  bool swap_bytes() const { return swap_bytes_; }
  bool cdr_encapsulation() const { return cdr_encapsulation_; }
  const TransportLocatorSeq& connection_info() const { return conn_info_; }

  // Managing associations to remote peers:

  bool associate(const AssociationData& peer, bool active);
  void disassociate(const RepoId& peerId);
  void stop_associating();
  void stop_associating(const GUID_t* repos, CORBA::ULong length);
  void send_final_acks();

  // Discovery:
  void register_for_reader(const RepoId& participant,
                           const RepoId& writerid,
                           const RepoId& readerid,
                           const TransportLocatorSeq& locators,
                           OpenDDS::DCPS::DiscoveryListener* listener);

  void unregister_for_reader(const RepoId& participant,
                             const RepoId& writerid,
                             const RepoId& readerid);

  void register_for_writer(const RepoId& participant,
                           const RepoId& readerid,
                           const RepoId& writerid,
                           const TransportLocatorSeq& locators,
                           DiscoveryListener* listener);

  void unregister_for_writer(const RepoId& participant,
                             const RepoId& readerid,
                             const RepoId& writerid);

  // Data transfer:

  bool send_response(const RepoId& peer,
                     const DataSampleHeader& header,
                     ACE_Message_Block* payload); // [DR]

  void send(SendStateDataSampleList send_list, ACE_UINT64 transaction_id = 0);

  SendControlStatus send_w_control(SendStateDataSampleList send_list,
                                   const DataSampleHeader& header,
                                   ACE_Message_Block* msg,
                                   const RepoId& destination);

  SendControlStatus send_control(const DataSampleHeader& header,
                                 ACE_Message_Block* msg);

  SendControlStatus send_control_to(const DataSampleHeader& header,
                                    ACE_Message_Block* msg,
                                    const RepoId& destination);

  bool remove_sample(const DataSampleElement* sample);
  bool remove_all_msgs();

  virtual void add_link(const DataLink_rch& link, const RepoId& peer);

  void on_notification_of_connection_deletion(const RepoId& peerId);

private:

  // Implemented by derived classes (DataReaderImpl/DataWriterImpl)
  virtual bool check_transport_qos(const TransportInst& inst) = 0;
  virtual const RepoId& get_repo_id() const = 0;
  virtual DDS::DomainId_t domain_id() const = 0;
  virtual Priority get_priority_value(const AssociationData& data) const = 0;
  virtual void transport_assoc_done(int /*flags*/, const RepoId& /*remote*/) {}

  // transport_detached() is called from TransportImpl when it shuts down
  friend class TransportImpl;
  void transport_detached(TransportImpl* which);

  // helpers
  typedef ACE_Guard<ACE_Thread_Mutex> Guard;
  void use_datalink_i(const RepoId& remote_id,
                      const DataLink_rch& link,
                      Guard& guard);
  TransportSendListener* get_send_listener();
  TransportReceiveListener* get_receive_listener();

  //helper for initiating connection, called by PendingAssoc objects
  //allows PendingAssoc to temporarily release lock_ to allow
  //TransportImpl to access Reactor if needed
  bool initiate_connect_i(TransportImpl::AcceptConnectResult& result,
                          const TransportImpl_rch impl,
                          const TransportImpl::RemoteTransport& remote,
                          const TransportImpl::ConnectionAttribs& attribs_,
                          Guard& guard);

  void send_i(SendStateDataSampleList send_list, ACE_UINT64 transaction_id);

  // A class, normally provided by an unit test, who needs access to a client's
  // privates.
  friend class ::DDS_TEST;

  typedef OPENDDS_MAP_CMP(RepoId, DataLink_rch, GUID_tKeyLessThan) DataLinkIndex;
  typedef OPENDDS_VECTOR(TransportImpl_rch) ImplsType;

  struct PendingAssoc : ACE_Event_Handler, public PoolAllocationBase {
    bool active_, removed_;
    ImplsType impls_;
    CORBA::ULong blob_index_;
    AssociationData data_;
    TransportImpl::ConnectionAttribs attribs_;

    PendingAssoc()
      : active_(false), removed_(false), blob_index_(0)
    {}

    bool initiate_connect(TransportClient* tc, Guard& guard);
    int handle_timeout(const ACE_Time_Value& time, const void* arg);
  };

  typedef OPENDDS_MAP_CMP(RepoId, PendingAssoc*, GUID_tKeyLessThan) PendingMap;

  class PendingAssocTimer : public ReactorInterceptor {
  public:
    PendingAssocTimer(ACE_Reactor* reactor,
                      ACE_thread_t owner)
      : ReactorInterceptor(reactor, owner)
    { }

    void schedule_timer(TransportClient* transport_client, PendingAssoc* pend)
    {
      ScheduleCommand c(this, transport_client, pend);
      execute_or_enqueue(c);
    }

    void cancel_timer(TransportClient* transport_client, PendingAssoc* pend)
    {
      CancelCommand c(this, transport_client, pend);
      execute_or_enqueue(c);
    }

    void delete_pending_assoc(PendingAssoc* pend)
    {
      DeleteCommand c(pend);
      // Always defer.
      enqueue(c);
    }

    virtual bool reactor_is_shut_down() const
    {
      return TheServiceParticipant->is_shut_down();
    }

  private:
    ~PendingAssocTimer()
    { }

    class CommandBase : public Command {
    public:
      CommandBase(PendingAssocTimer* timer,
                  TransportClient* transport_client,
                  PendingAssoc* assoc)
        : timer_ (timer)
        , transport_client_ (transport_client)
        , assoc_ (assoc)
      { }
    protected:
      PendingAssocTimer* timer_;
      TransportClient* transport_client_;
      PendingAssoc* assoc_;
    };
    struct ScheduleCommand : public CommandBase {
      ScheduleCommand(PendingAssocTimer* timer,
                      TransportClient* transport_client,
                      PendingAssoc* assoc)
        : CommandBase (timer, transport_client, assoc)
      { }
      virtual void execute()
      {
        if (timer_->reactor()) {
          timer_->reactor()->schedule_timer(assoc_, transport_client_, transport_client_->passive_connect_duration_);
        }
      }
    };
    struct CancelCommand : public CommandBase {
      CancelCommand(PendingAssocTimer* timer,
                    TransportClient* transport_client,
                    PendingAssoc* assoc)
        : CommandBase (timer, transport_client, assoc)
      { }
      virtual void execute()
      {
        if (timer_->reactor()) {
          timer_->reactor()->cancel_timer(assoc_);
        }
      }
    };
    struct DeleteCommand : public CommandBase {
      DeleteCommand(PendingAssoc* assoc)
        : CommandBase (0, 0, assoc)
      { }
      virtual void execute()
      {
        delete assoc_;
      }
    };
  };
  PendingAssocTimer* pending_assoc_timer_;

  // Associated Impls and DataLinks:

  ImplsType impls_;
  PendingMap pending_;
  DataLinkSet links_;
  DataLinkIndex links_waiting_for_on_deleted_callback_;

  /// These are the links being used during the call to send(). This is made a member of the
  /// class to minimize allocation/deallocations of the data link set.
  DataLinkSet send_links_;

  DataLinkIndex data_link_index_;

  // Used to allow sends to completed as a transaction and block
  // multi-threaded writers from proceeding to send data
  // on two thread simultaneously, which could cause out-of-order data.
  ACE_Thread_Mutex send_transaction_lock_;
  ACE_UINT64 expected_transaction_id_;
  ACE_UINT64 max_transaction_id_seen_;

  //max_transaction_tail_ will always be the tail of the
  //max transaction that has been observed or 0 if this is
  //the first transaction or a transaction after the expected
  //value was met and thus reset to 0 indicating the samples were
  //sent up to max_transaction_id_
  DataSampleElement* max_transaction_tail_;

  // Configuration details:

  bool swap_bytes_, cdr_encapsulation_, reliable_, durable_;

  ACE_Time_Value passive_connect_duration_;

  TransportLocatorSeq conn_info_;

  //Seems to protect accesses to impls_, pending_, links_, data_link_index_
  ACE_Thread_Mutex lock_;

  typedef ACE_Reverse_Lock<ACE_Thread_Mutex> Reverse_Lock_t;
  Reverse_Lock_t reverse_lock_;

  RepoId repo_id_;
};

}
}

#endif

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