server/dep/acelite/ace/Dynamic_Service_Dependency.h
2023-01-01 00:55:45 +00:00

70 lines
2.2 KiB
C++

// -*- C++ -*-
//=============================================================================
/**
* @file Dynamic_Service_Dependency.h
*
* $Id: Dynamic_Service_Dependency.h 80826 2008-03-04 14:51:23Z wotte $
*
* @author Iliyan Jeliazkov <iliyan@ociweb.com>
*/
//=============================================================================
#ifndef ACE_DYNAMIC_SERVICE_DEPENDENCY_H
#define ACE_DYNAMIC_SERVICE_DEPENDENCY_H
#include /**/ "ace/pre.h"
#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */
#include "ace/Dynamic_Service_Base.h"
#include "ace/Service_Object.h"
#include "ace/DLL.h"
ACE_BEGIN_VERSIONED_NAMESPACE_DECL
/**
* @class ACE_Dynamic_Service_Dependency
*
* @brief Provides a way to declare dependency on specific service,
* thus helping to avoid order of initialization issues with instances
* of an objects whose implementation code resides in dynamically loaded
* services.
*
* It is disastrous to have dynamically loadable services create and give away
* ownership of objects and then ending up being unloaded before all those
* instances have been deleted. Normally the code for such objects classes
* resides within the TEXT segment of the DLL, which implements the service.
* If a service gets removed, its DLL may be unmapped from memory and then
* any attempt to invoke a method on the said objects will cause SEGV.
*
* Such instances must contain a member of ACE_Dynamic_Service_Dependency
* initialized with the service they depend on.
* ACE_Dynamic_Service_Dependency's constructor and destructor are
* "magical" - they work by maintaining the underlying dynamic service's
* DLL reference count.
*/
class ACE_Export ACE_Dynamic_Service_Dependency
{
public:
ACE_Dynamic_Service_Dependency (const ACE_Service_Gestalt *cfg,
const ACE_TCHAR *principal);
ACE_Dynamic_Service_Dependency (const ACE_TCHAR *principal);
~ACE_Dynamic_Service_Dependency (void);
private:
void init (const ACE_Service_Gestalt *cfg, const ACE_TCHAR *principal);
private:
ACE_DLL tracker_;
};
ACE_END_VERSIONED_NAMESPACE_DECL
#include /**/ "ace/post.h"
#endif /* ACE_DYNAMIC_SERVICE_DEPENDENCY_H */