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Diffstat (limited to 'TAO/examples/POA/Loader/Servant_Locator.h')
| -rw-r--r-- | TAO/examples/POA/Loader/Servant_Locator.h | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/TAO/examples/POA/Loader/Servant_Locator.h b/TAO/examples/POA/Loader/Servant_Locator.h new file mode 100644 index 00000000000..06396147ff5 --- /dev/null +++ b/TAO/examples/POA/Loader/Servant_Locator.h @@ -0,0 +1,117 @@ +// This may look like C, but it's really -*- C++ -*- +// $Id$ + +// ================================================================ +// +// = LIBRARY +// TAO/examples/POA/Loader +// +// = FILENAME +// Servant_Locator.h +// +// = DESCRIPTION +// Defines a ServantLocator class , used with a POA having +// a NON_RETAIN policy. +// +// = AUTHOR +// Kirthika Parameswaran <kirthika@cs.wustl.edu> +// +// ================================================================ + +#ifndef SERVANT_LOCATOR_H +#define SERVANT_LOCATOR_H + +#include "tao/PortableServer/PortableServer.h" +#include "tao/PortableServer/ServantLocatorC.h" +#include "tao/LocalObject.h" + +#include "tao/ORB.h" + +#include "ace/DLL.h" +#include "ace/SString.h" +#include "ace/Log_Msg.h" + +class ServantLocator : + public virtual PortableServer::ServantLocator, + public virtual TAO_Local_RefCounted_Object +{ + // = TITLE + // This class is used by a POA with USE_SERVANT_MANAGER and + // NON_RETAIN policy. + // + // = DESCRIPTION + // This class defines the Servant Locator interface of the Servant + // Manager. It is invoked when the POA has an USE_SERVANT_MANAGER + // policy and a servant_retention policy of NON_RETAIN type. +public: + typedef PortableServer::Servant + (*SERVANT_FACTORY) (const PortableServer::ObjectId &oid, + PortableServer::POA_ptr poa, + CORBA::ORB_ptr orb); + // This typedef is used to typecast the void* obtained when finding + // a symbol in the dll. Invoking the function pointer obtained would + // get a servant. + + typedef void + (*SERVANT_GARBAGE_COLLECTOR) (const PortableServer::ObjectId &oid, + PortableServer::POA_ptr, + PortableServer::Servant servant); + // This typedef is used to obtain the garbage_collection_function symbol + // in the dll. Invoking the function pointer obtained would then destroy + // the servant. + + ServantLocator (CORBA::ORB_ptr orb, + const char *dllname, + const char *factory_function, + const char *garbage_collection_function); + // Constructor. + + virtual PortableServer::Servant preinvoke (const PortableServer::ObjectId &oid, + PortableServer::POA_ptr adapter, + const char *operation, + PortableServer::ServantLocator::Cookie &the_cookie); + // This method is invoked by a POA whenever it receives a request + // for test object that is not currently active. When the POA is + // created using the NON_RETAIN policy the Active Object Map is not + // maintained, in other words, an association between the ObjectId + // and the servant is not maintained. Hence every client request the + // servant has to be loaded. Note the operation argument. This + // argument specifies the operation to be invoked on the + // servant. The cookie helps in marking the servant. This marking is + // useful while destroying the servant. + + virtual void postinvoke (const PortableServer::ObjectId &oid, + PortableServer::POA_ptr adapter, + const char *operation, + PortableServer::ServantLocator::Cookie the_cookie, + PortableServer::Servant the_servant); + // This method is invoked whenever a test servant completes a + // request. As the Servant Loactor interface is used when the POA + // doesnt maintain the Active Object Map, its necessary to get rid + // of the servant after the client request has been processed. The + // appropriate servant is destroyed by verifying the cookie.Again + // this method is invoked per client request. + +private: + ACE_CString dllname_; + // The name of the dll containing the servant. + + ACE_CString create_symbol_; + // The symbol which on getting invoked will give us the servant + // pointer. + + ACE_DLL dll_; + // The ACE_DLL object which performs the task of loading the dll + // and accessing it. + + SERVANT_FACTORY servant_supplier_; + // The function pointer of factory_function type. + + SERVANT_GARBAGE_COLLECTOR servant_garbage_collector_; + // The function pointer of garbage_collection_function type. + + CORBA::ORB_var orb_; + // A reference to the ORB. +}; + +#endif /* SERVANT_LOCATOR_H */ |