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Diffstat (limited to 'TAO/orbsvcs/orbsvcs/ESF/ESF_Proxy_RefCount_Guard.h')
-rw-r--r-- | TAO/orbsvcs/orbsvcs/ESF/ESF_Proxy_RefCount_Guard.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/TAO/orbsvcs/orbsvcs/ESF/ESF_Proxy_RefCount_Guard.h b/TAO/orbsvcs/orbsvcs/ESF/ESF_Proxy_RefCount_Guard.h new file mode 100644 index 00000000000..cac01eb47f4 --- /dev/null +++ b/TAO/orbsvcs/orbsvcs/ESF/ESF_Proxy_RefCount_Guard.h @@ -0,0 +1,79 @@ +// -*- C++ -*- + +/** + * @file ESF_Proxy_RefCount_Guard.h + * + * $Id$ + * + * @author Carlos O'Ryan (coryan@cs.wustl.edu) + * + * http://doc.ece.uci.edu/~coryan/EC/index.html + */ + +#ifndef TAO_ESF_PROXY_REFCOUNT_GUARD_H +#define TAO_ESF_PROXY_REFCOUNT_GUARD_H + +#include "tao/Basic_Types.h" + +#if !defined (ACE_LACKS_PRAGMA_ONCE) +# pragma once +#endif /* ACE_LACKS_PRAGMA_ONCE */ + +TAO_BEGIN_VERSIONED_NAMESPACE_DECL + +/** + * @class TAO_ESF_Proxy_RefCount_Guard + * + * @brief Reference count based guard. + * + * A common idiom used on event services is to increment a + * reference count before starting a long running operation. + * The system can then execute the operation without any risk of + * having the underlying object destroyed. The advantage of using + * a reference count is that no mutex or lock needs to be held + * while the operation is beign executed. + * This class implements that common idiom, but it also adds hooks + * to handle scenarios where more than one operation is performed + * while holding the reference count. + * + * @TODO: The type of lock could be parametric + */ +template<class EVENT_CHANNEL, class PROXY> +class TAO_ESF_Proxy_RefCount_Guard +{ +public: + /// Constructor + TAO_ESF_Proxy_RefCount_Guard (CORBA::ULong &refcount, + EVENT_CHANNEL *ec, + PROXY *proxy); + + /// Destructor + ~TAO_ESF_Proxy_RefCount_Guard (void); + +protected: + /// The reference count, if it gets to zero then the object must be + /// destroyed + CORBA::ULong &refcount_; + + /// The event channel used to destroy the proxy + EVENT_CHANNEL *event_channel_; + + /// The proxy whose lifetime is controlled by the reference count + PROXY *proxy_; +}; + +TAO_END_VERSIONED_NAMESPACE_DECL + +#if defined (__ACE_INLINE__) +#include "orbsvcs/ESF/ESF_Proxy_RefCount_Guard.inl" +#endif /* __ACE_INLINE__ */ + +#if defined (ACE_TEMPLATES_REQUIRE_SOURCE) +#include "orbsvcs/ESF/ESF_Proxy_RefCount_Guard.cpp" +#endif /* ACE_TEMPLATES_REQUIRE_SOURCE */ + +#if defined (ACE_TEMPLATES_REQUIRE_PRAGMA) +#pragma implementation ("ESF_Proxy_RefCount_Guard.cpp") +#endif /* ACE_TEMPLATES_REQUIRE_PRAGMA */ + +#endif /* TAO_ESF_PROXY_REFCOUNT_GUARD_H */ |