TAO/tao/Synch_Invocation.h

   1 // -*- C++ -*-
   2 //=============================================================================
   3 /**
   4  *  @file    Synch_Invocation.h
   5  *
   6  *  @author Balachandran Natarajan <bala@dre.vanderbilt.edu>
   7  */
   8 //=============================================================================
   9 #ifndef TAO_SYNCH_INVOCATION_H
  10 #define TAO_SYNCH_INVOCATION_H
  11 #include /**/ "ace/pre.h"
  12
  13 #include "tao/Remote_Invocation.h"
  14
  15 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  16 # pragma once
  17 #endif /* ACE_LACKS_PRAGMA_ONCE */
  18
  19 #include "tao/orbconf.h"
  20
  21 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  22 class ACE_Time_Value;
  23 ACE_END_VERSIONED_NAMESPACE_DECL
  24
  25 TAO_BEGIN_VERSIONED_NAMESPACE_DECL
  26
  27 class TAO_Operation_Details;
  28 class TAO_Synch_Reply_Dispatcher;
  29 class TAO_InputCDR;
  30 class TAO_Bind_Dispatcher_Guard;
  31
  32 namespace TAO
  33 {
  34   class Profile_Transport_Resolver;
  35   class Invocation_Retry_State;
  36
  37   /**
  38    * @class Synch_Twoway_Invocation
  39    *
  40    * @brief All the action for a synchronous twoway invocation happen
  41    * here.
  42    *
  43    * An object of this type is created by TAO::Invocation_Adapter
  44    * and invokes a method on this class. The method takes care of
  45    * creating and sending a request, waiting for a reply and
  46    * demarshalling the reply for the client.
  47    *
  48    */
  49   class TAO_Export Synch_Twoway_Invocation : public Remote_Invocation
  50   {
  51   public:
  52     /// Constructor used by TAO::Invocation_Adapter
  53     /**
  54      * @param otarget The original target on which this invocation
  55      * was started. This is there to be passed up to its parent
  56      * class.
  57      *
  58      * @param resolver The profile and transport holder.
  59      *
  60      * @param detail Operation details of the invocation on the target
  61      *
  62      * @param response_expected Flag to indicate whether the
  63      * operation encapsulated by @a op returns a response or not.
  64      */
  65     Synch_Twoway_Invocation (CORBA::Object_ptr otarget,
  66                              Profile_Transport_Resolver &resolver,
  67                              TAO_Operation_Details &detail,
  68                              bool response_expected = true);
  69
  70     /// Method used by the adapter to kickstart an invocation to the
  71     /// remote object.
  72     /**
  73      * There is a exception declaration in this method which ensures
  74      * that the exceptions propagated by the remote objects are
  75      * converted a CORBA exceptions for the clients. This method does
  76      * a bunch of things necessary to create and send the
  77      * invocation. This method is also nerve centre for the
  78      * interceptor invocation points.
  79      */
  80     Invocation_Status remote_twoway (ACE_Time_Value *max_wait_time);
  81
  82     /**
  83      * Indicate that retry state should be tracked and controlled
  84      * in the presence of exceptions.
  85      */
  86     void set_retry_state (Invocation_Retry_State *retry_state);
  87
  88   protected:
  89     /**
  90      * This method is selectively made virtual, so that inherited
  91      * classes can overload the  user exception handling type. For
  92      * example the DII needs a totally different method of
  93      * user exception exception handling
  94      */
  95     virtual Invocation_Status handle_user_exception (TAO_InputCDR &cdr);
  96
  97     /// Helper method used to handle location forwarded replies.
  98     Invocation_Status location_forward (TAO_InputCDR &cdr);
  99
 100     /// Helper method used to handle system exceptions from the remote
 101     /// objects.
 102     Invocation_Status handle_system_exception (TAO_InputCDR &cdr);
 103
 104     /// As the name suggests waits for a reply from the remote ORB.
 105     /**
 106      * This method returns an exception when there is an error.
 107      */
 108     Invocation_Status wait_for_reply (ACE_Time_Value *max_wait_time,
 109                                       TAO_Synch_Reply_Dispatcher &rd,
 110                                       TAO_Bind_Dispatcher_Guard &bd);
 111
 112     Invocation_Retry_State *retry_state_;
 113
 114   private:
 115     /// Helper method that checks the reply status of the
 116     /// replies and takes appropriate action.
 117     /**
 118      * This method returns an exception when there is an error.
 119      */
 120     Invocation_Status check_reply_status (TAO_Synch_Reply_Dispatcher &rd);
 121   };
 122
 123   /**
 124    * @class Synch_Oneway_Invocation
 125    *
 126    * @brief All the action for a synchronous oneway invocation happen
 127    * here.
 128    *
 129    * This class inherits from twoway invocation for the following
 130    * reasons
 131    *
 132    * - We deal with oneway invocation in more or less the same way as
 133    *   two but for waiting for the reply
 134    *
 135    * - For some SYNC_SCOPE policies namely SYNC_WITH_TARGET and
 136    *   SYNC_WITH_SERVER the invocation classes have to treat the
 137    *   invocation as a twoway invocation (more or less)
 138    */
 139   class TAO_Export Synch_Oneway_Invocation
 140     : public Synch_Twoway_Invocation
 141   {
 142   public:
 143     /// Constructor used by TAO::Invocation_Adapter
 144     /**
 145      * @param otarget The original target on which this invocation
 146      * was started. This is there to be passed up to its parent
 147      * class.
 148      *
 149      * @param resolver The profile and transport holder.
 150      *
 151      * @param detail Operation details of the invocation on the target
 152      */
 153     Synch_Oneway_Invocation (CORBA::Object_ptr otarget,
 154                              Profile_Transport_Resolver &resolver,
 155                              TAO_Operation_Details &detail);
 156
 157     /// Method used by the adapter to kickstart an oneway invocation
 158     /// to the remote object.
 159     Invocation_Status remote_oneway (ACE_Time_Value *max_wait_time);
 160   };
 161
 162   /**
 163    * @class Reply_Guard
 164    *
 165    * @brief A guard class used for storing and forwarding the reply
 166    *  status to the portable interceptors.
 167    */
 168   class TAO_Export Reply_Guard
 169   {
 170   public:
 171     Reply_Guard (Invocation_Base *s, Invocation_Status is);
 172
 173     /// The destructor calls Invocation_Base::invoke_status with the
 174     /// right invoke status, which is useful for PI's.
 175     ~Reply_Guard ();
 176
 177     /// Mutator to set the invocation status.
 178     void set_status (Invocation_Status s);
 179
 180   private:
 181     Reply_Guard (Reply_Guard const &);
 182     Reply_Guard & operator= (Reply_Guard const &);
 183
 184   private:
 185     Invocation_Base * const invocation_;
 186     Invocation_Status status_;
 187   };
 188 }
 189
 190 TAO_END_VERSIONED_NAMESPACE_DECL
 191
 192 #if defined (__ACE_INLINE__)
 193 # include "tao/Synch_Invocation.inl"
 194 #endif /* __ACE_INLINE__ */
 195
 196 #include /**/ "ace/post.h"
 197 #endif /*TAO_SYNCH_INVOCATION_H*/