TAO/tao/CSD_Framework/CSD_Strategy_Base.h

   1 // -*- C++ -*-
   2
   3 //=============================================================================
   4 /**
   5  *  @file    CSD_Strategy_Base.h
   6  *
   7  *  @author  Tim Bradley <bradley_t@ociweb.com>
   8  */
   9 //=============================================================================
  10
  11 #ifndef TAO_CSD_FW_CUSTOM_SERVANT_DISPATCHING_STRATEGY_H
  12 #define TAO_CSD_FW_CUSTOM_SERVANT_DISPATCHING_STRATEGY_H
  13
  14 #include /**/ "ace/pre.h"
  15
  16 #include "tao/CSD_Framework/CSD_FW_Export.h"
  17
  18 #include "tao/PortableServer/PortableServer.h"
  19 #include "tao/PortableServer/Servant_Upcall.h"
  20 #include "tao/PortableServer/Servant_Base.h"
  21 #include "tao/TAO_Server_Request.h"
  22 #include "tao/LocalObject.h"
  23
  24
  25 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  26 # pragma once
  27 #endif /* ACE_LACKS_PRAGMA_ONCE */
  28
  29 #include "tao/CSD_Framework/CSD_FrameworkC.h"
  30
  31 TAO_BEGIN_VERSIONED_NAMESPACE_DECL
  32
  33 class TAO_Root_POA;
  34 namespace PortableServer
  35 {
  36   class POAManager;
  37 }
  38
  39 namespace TAO
  40 {
  41   namespace CSD
  42   {
  43     /**
  44     * @class Strategy_Base
  45     *
  46     * @brief Base class for all Custom Servant Dispatching Strategies.
  47     *
  48     * This class serves as the base class for all "custom" strategies that
  49     * perform servant dispatching.  An instance of (a subclass of) this class
  50     * can be applied to a POA object.  Any servant requests for the POA will
  51     * be "dispatched" to this strategy object.
  52     *
  53     */
  54     class TAO_CSD_FW_Export Strategy_Base
  55       : public CSD_Framework::Strategy,
  56         public ::CORBA::LocalObject
  57     {
  58     public:
  59       /// Result Type for dispatching method(s).
  60       enum DispatchResult
  61       {
  62         // The request dispatching has been handled.
  63         DISPATCH_HANDLED,
  64
  65         // The request dispatching has been rejected.
  66         DISPATCH_REJECTED,
  67
  68         // Defer to "default" dispatching strategy (use the caller's thread).
  69         DISPATCH_DEFERRED
  70       };
  71
  72       /// Virtual Destructor.
  73       virtual ~Strategy_Base();
  74
  75       /// This method is invoked to "attach" this strategy object to
  76       /// the supplied POA.  Returns true for success, and false for failure.
  77       CORBA::Boolean apply_to(PortableServer::POA_ptr poa );
  78
  79     protected:
  80       /// Default Constructor.
  81       Strategy_Base();
  82
  83       /// Subclass provides implementation to dispatch a remote request.
  84       virtual DispatchResult dispatch_remote_request_i
  85                             (TAO_ServerRequest&              server_request,
  86                               const PortableServer::ObjectId& object_id,
  87                               PortableServer::POA_ptr         poa,
  88                               const char*                     operation,
  89                               PortableServer::Servant         servant) = 0;
  90
  91       /// Subclass provides implementation to dispatch a collocated request.
  92       virtual DispatchResult dispatch_collocated_request_i
  93                           (TAO_ServerRequest&              server_request,
  94                           const PortableServer::ObjectId& object_id,
  95                           PortableServer::POA_ptr         poa,
  96                           const char*                     operation,
  97                           PortableServer::Servant         servant) = 0;
  98
  99       /// Event - The POA has been activated.
 100       virtual bool poa_activated_event_i(TAO_ORB_Core& orb_core) = 0;
 101
 102       /// Event - The POA has been deactivated.
 103       virtual void poa_deactivated_event_i() = 0;
 104
 105       /// Event - A servant has been activated.
 106       virtual void servant_activated_event_i
 107                                   (PortableServer::Servant servant,
 108                                    const PortableServer::ObjectId& oid);
 109
 110       /// Event - A servant has been deactivated.
 111       virtual void servant_deactivated_event_i
 112                                   (PortableServer::Servant servant,
 113                                   const PortableServer::ObjectId& oid);
 114
 115     private:
 116       /// Only our friend, the proxy, is allowed to invoke our private operations.
 117       /// This allows us to not pollute the public interface of the CSD Strategy_Base
 118       /// subclasses with methods that should never be called (except by the
 119       /// proxy, of course).
 120       friend class Strategy_Proxy;
 121
 122       /// This CSD Strategy_Base has been asked to dispatch a (collocated or remote)
 123       /// request.
 124       void dispatch_request(TAO_ServerRequest& server_request,
 125                             ::TAO::Portable_Server::Servant_Upcall& upcall);
 126
 127       /// Event - The POA has been activated. This happens when the POA_Manager
 128       ///         is activated.
 129       bool poa_activated_event(TAO_ORB_Core& orb_core);
 130
 131       /// Event - The POA has been deactivated.  This happens when the
 132       ///         POAManager is deactivated, or when the POA is destroyed.
 133       void poa_deactivated_event();
 134
 135       /// Event - A servant has been activated.
 136       void servant_activated_event(PortableServer::Servant servant,
 137                                   const PortableServer::ObjectId& oid);
 138
 139       /// Event - A servant has been deactivated.  This also occurs when
 140       ///         the POA is destroyed.
 141       void servant_deactivated_event(PortableServer::Servant servant,
 142                                      const PortableServer::ObjectId& oid);
 143
 144       /// The POA to which this strategy has been applied.
 145       ::PortableServer::POA_var poa_;
 146
 147       /// This flag indicates that the POA is currently active (true) or
 148       /// currently inactive (false).
 149       bool poa_activated_;
 150     };
 151   }
 152 }
 153
 154 TAO_END_VERSIONED_NAMESPACE_DECL
 155
 156 #if defined (__ACE_INLINE__)
 157 # include "tao/CSD_Framework/CSD_Strategy_Base.inl"
 158 #endif /* __ACE_INLINE__ */
 159
 160 #include /**/ "ace/post.h"
 161
 162 #endif /* TAO_CSD_FW_CUSTOM_SERVANT_DISPATCHING_STRATEGY_H */