TAO/tests/POA/On_Demand_Loading/Servant_Manager.cpp

   1
   2 //=============================================================================
   3 /**
   4  *  @file     Servant_Manager.cpp
   5  *
   6  *   Implementation of the helper class for the ServantActivator_i
   7  *   and the ServantLocator_i.
   8  *
   9  *  @author  Kirthika Parameswaran <kirthika@cs.wustl.edu>
  10  */
  11 //=============================================================================
  12
  13
  14 #include "Servant_Manager.h"
  15 #include "tao/debug.h"
  16
  17 // Initialization.
  18 ServantManager_i::ServantManager_i (CORBA::ORB_ptr orb)
  19   : orb_ (CORBA::ORB::_duplicate (orb))
  20 {
  21 }
  22
  23 // Destruction.
  24 ServantManager_i::~ServantManager_i ()
  25 {
  26 }
  27
  28 // This method loads the dynamically linked DLL which is the servant
  29 // and returns the servant object which is then used for other
  30 // operations in the DLL.
  31
  32 PortableServer::Servant
  33 ServantManager_i::obtain_servant (const ACE_TCHAR *str,
  34                                   PortableServer::POA_ptr poa)
  35 {
  36   // The string format is <dllname:factory_function> that must be
  37   // parsed.
  38   this->parse_string (str);
  39
  40   // Create the DLL object.
  41   ACE_DLL *dll = 0;
  42
  43   ACE_NEW_RETURN (dll,
  44                   ACE_DLL,
  45                   0);
  46
  47   // Obtain the ObjectId from the string argument.
  48
  49   PortableServer::ObjectId_var oid =
  50     PortableServer::string_to_ObjectId (ACE_TEXT_ALWAYS_CHAR (str));
  51
  52   if (TAO_debug_level > 0)
  53     ACE_DEBUG ((LM_DEBUG,
  54                 "before bind\n"));
  55   // Make an HASH_MAP entry by binding the object_id and the DLL
  56   // object associated with it together.
  57   if (this->servant_map_.bind (oid.in (),
  58                                dll) == -1)
  59     ACE_ERROR_RETURN ((LM_ERROR,
  60                        "%p\n",
  61                        "Bind failed"),
  62                       0);
  63   // Now that the dll name is available we open the dll.
  64   if (dll->open (dllname_.c_str ()) == -1)
  65     ACE_ERROR_RETURN ((LM_ERROR,
  66                        "%p",
  67                        dll->error ()),
  68                       0);
  69
  70   // The next step is to obtain the symbol for the function that will
  71   // create the servant object and return it.
  72
  73   // Cannot go from void* to function pointer directly. Cast the void*
  74   // to long first.
  75   void *symbol = dll->symbol (create_symbol_.c_str ());
  76   intptr_t function = reinterpret_cast<intptr_t> (symbol);
  77
  78   SERVANT_FACTORY servant_creator =
  79     reinterpret_cast<SERVANT_FACTORY> (function);
  80
  81   // Checking whether it is possible to create the servant.
  82   if (servant_creator == 0)
  83     ACE_ERROR_RETURN ((LM_ERROR,
  84                        "%p",
  85                        dll->error ()),
  86                       0);
  87
  88   // Now create and return the servant using the <servant_creator>
  89   // factory function.
  90   return (*servant_creator) (this->orb_.in (),
  91                              poa);
  92 }
  93
  94 // The objectID is in a format of dllname:factory_function which has
  95 // to be parsed and separated into tokens to be used.
  96
  97 void
  98 ServantManager_i::parse_string (const ACE_TCHAR *s)
  99 {
 100   // The format of the objectid is <dll:factory_function>.  This
 101   // string is parsed to obtain the dll name and the function name
 102   // which will create trhe servant and return it to us.
 103
 104   ACE_TString str (s);
 105
 106   ACE_TString::size_type index = str.find (':');
 107   // On error, npos is returned.
 108   if (index == ACE_CString::npos)
 109     ACE_ERROR ((LM_ERROR,
 110                 "Required character absent!\n"));
 111
 112   // The index gives us the location which is equivalent to the size
 113   // of the dllname_ string.
 114   this->dllname_ = str.substr (0, index);
 115
 116   // Obtain the substring from the offset which is one greater than
 117   // the location of ':'.
 118   this->create_symbol_ = str.substr (index + 1);
 119
 120   if (TAO_debug_level > 0)
 121     ACE_DEBUG ((LM_DEBUG,
 122                 "the servant dll:%s\n the factory_function:%s\n",
 123                 this->dllname_.c_str (),
 124                 this->create_symbol_.c_str ()));
 125 }
 126
 127 // This method returns an ObjectId when given a DLL name and the
 128 // factory function to be invoked in the DLL.  The format of the
 129 // ObjectId is libname:factory_function.
 130
 131 PortableServer::ObjectId_var
 132 ServantManager_i::create_dll_object_id (const char *libname,
 133                                         const char *factory_function)
 134 {
 135   ACE_CString format_string = libname;
 136   format_string += ":";
 137   format_string += factory_function;
 138
 139   ACE_DEBUG ((LM_DEBUG,
 140               "format-string is %C\n",
 141               format_string.c_str ()));
 142   // The object ID is created.
 143   PortableServer::ObjectId_var oid =
 144     PortableServer::string_to_ObjectId (format_string.c_str ());
 145   return oid;
 146 }
 147
 148 // This method destroys the servant and its caretaking DLL object.
 149
 150 void
 151 ServantManager_i::destroy_servant (PortableServer::Servant servant,
 152                                    const PortableServer::ObjectId &oid)
 153 {
 154   // The servant is destroyed.
 155   delete servant;
 156
 157   // Since the servant is no more the DLL object associated with it
 158   // has to be destroyed too.
 159
 160   ACE_DLL *dll = 0;
 161
 162   // Since the servant is no more the DLL object associated with it
 163   // has to be destroyed too.
 164
 165   if (this->servant_map_.unbind (oid,
 166                                  dll) == -1)
 167     ACE_ERROR ((LM_ERROR,
 168                 "%p\n",
 169                 "Unbind failed!\n"));
 170   delete dll;
 171 }
 172