ACE/ace/Service_Object.h

   1 /* -*- C++ -*- */
   2
   3 //=============================================================================
   4 /**
   5  *  @file    Service_Object.h
   6  *
   7  *  @author Douglas C. Schmidt <d.schmidt@vanderbilt.edu>
   8  */
   9 //=============================================================================
  10
  11 #ifndef ACE_SERVICE_OBJECT_H
  12 #define ACE_SERVICE_OBJECT_H
  13 #include /**/ "ace/pre.h"
  14
  15 #include "ace/Shared_Object.h"
  16 #include "ace/Svc_Conf_Tokens.h"
  17
  18 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  19 # pragma once
  20 #endif /* ACE_LACKS_PRAGMA_ONCE */
  21
  22 #include "ace/Event_Handler.h"
  23 #include "ace/DLL.h"
  24
  25 #include "ace/Service_Gestalt.h"
  26
  27 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  28
  29 #define ACE_Component ACE_Service_Object
  30
  31 /**
  32  * @class ACE_Service_Object
  33  *
  34  * @brief Provide the abstract base class common to all service
  35  * implementations.
  36  *
  37  * Classes that inherit from ACE_Service_Objects are capable
  38  * of being registered with the ACE_Reactor (due to the
  39  * ACE_Event_Handler, as well as being dynamically linked by
  40  * the ACE_Service_Config (due to the ACE_Shared_Object).
  41  */
  42 class ACE_Export ACE_Service_Object
  43   : public ACE_Event_Handler,
  44     public ACE_Shared_Object
  45 {
  46 public:
  47   /// Constructor.
  48   ACE_Service_Object (ACE_Reactor * = 0);
  49
  50   /// Destructor.
  51   virtual ~ACE_Service_Object ();
  52
  53   /// Temporarily disable a service without removing it completely.
  54   virtual int suspend ();
  55
  56   /// Re-enable a previously suspended service.
  57   virtual int resume ();
  58
  59   /// Declare the dynamic allocation hooks.
  60   ACE_ALLOC_HOOK_DECLARE;
  61 };
  62
  63 // Forward decl.
  64 class ACE_Service_Type_Impl;
  65
  66 /**
  67  * @class ACE_Service_Type
  68  *
  69  * @brief Keeps track of information related to the various
  70  * ACE_Service_Type_Impl subclasses.
  71  *
  72  * This class acts as the interface of the "Bridge" pattern.
  73  */
  74 class ACE_Export ACE_Service_Type
  75 {
  76 public:
  77   enum
  78   {
  79     /// Delete the payload object.
  80     DELETE_OBJ = 1,
  81
  82     /// Delete the enclosing object.
  83     DELETE_THIS = 2
  84   };
  85
  86   enum
  87     {
  88       SERVICE_OBJECT = ACE_SVC_OBJ_T,
  89       MODULE = ACE_MODULE_T,
  90       STREAM = ACE_STREAM_T,
  91       INVALID_TYPE = -1
  92     };
  93
  94   ACE_Service_Type (const ACE_TCHAR *n,
  95                     ACE_Service_Type_Impl *o,
  96                     const ACE_DLL &dll,
  97                     bool active);
  98   ACE_Service_Type (const ACE_TCHAR *n,
  99                     ACE_Service_Type_Impl *o,
 100                     ACE_SHLIB_HANDLE handle,
 101                     bool active);
 102   ~ACE_Service_Type ();
 103
 104   const ACE_TCHAR *name () const;
 105   void name (const ACE_TCHAR *);
 106
 107   const ACE_Service_Type_Impl *type () const;
 108   void type (const ACE_Service_Type_Impl *, bool active = true);
 109
 110   /// Is this just a stub for the real thing?
 111   bool is_forward_declaration () const;
 112
 113   int suspend () const;
 114   int resume () const;
 115   bool active () const;
 116   void active (bool turnon);
 117
 118   /// Calls @c fini on @c type_
 119   int fini ();
 120
 121   /// Check if the service has been fini'ed.
 122   bool fini_called () const;
 123
 124   /// Dump the state of an object.
 125   void dump () const;
 126
 127   /// Get to the DLL's implentation
 128   const ACE_DLL & dll () const;
 129
 130   /// Sets the DLL
 131   void dll (const ACE_DLL&);
 132
 133   /// Declare the dynamic allocation hooks.
 134   ACE_ALLOC_HOOK_DECLARE;
 135
 136 private:
 137   /// Humanly readible name of svc.
 138   const ACE_TCHAR *name_;
 139
 140   /// Pointer to C++ object that implements the svc.
 141   const ACE_Service_Type_Impl *type_;
 142
 143   /// ACE_DLL representing the shared object file (non-zero if
 144   /// dynamically linked).
 145   mutable ACE_DLL dll_;
 146
 147   /// true if svc is currently active, otherwise false.
 148   bool active_;
 149
 150   /// true if @c fini on @c type_ has already been called, otherwise false.
 151   bool fini_already_called_;
 152 };
 153
 154 /**
 155  * @class ACE_Service_Object_Ptr
 156  *
 157  * @brief This is a smart pointer that holds onto the associated
 158  * ACE_Service_Object * until the current scope is left, at
 159  * which point the object's fini() hook is called and the
 160  * service_object_ gets deleted.
 161  *
 162  * This class is similar to the Standard C++ Library class
 163  * auto_ptr. It is used in conjunction with statically linked
 164  * ACE_Service_Objects, as shown in the ./netsvcs/server/main.cpp example.
 165  */
 166 class ACE_Export ACE_Service_Object_Ptr
 167 {
 168 public:
 169   /// Acquire ownership of the @a so.
 170   ACE_Service_Object_Ptr (ACE_Service_Object *so);
 171
 172   /// Release the held ACE_Service_Object by calling its fini() hook.
 173   ~ACE_Service_Object_Ptr ();
 174
 175   /// Smart pointer to access the underlying ACE_Service_Object.
 176   ACE_Service_Object *operator-> ();
 177
 178 private:
 179   /// Holds the service object until we're done.
 180   ACE_Service_Object *service_object_;
 181 };
 182
 183 ACE_END_VERSIONED_NAMESPACE_DECL
 184
 185 #if defined (__ACE_INLINE__)
 186 #include "ace/Service_Object.inl"
 187 #endif /* __ACE_INLINE__ */
 188
 189 #include /**/ "ace/post.h"
 190 #endif /* ACE_SERVICE_OBJECT_H */