//////////////////////////////////////////////////////////////////////////////// // The Loki Library // Copyright (c) 2000 Andrei Alexandrescu // Copyright (c) 2000 Petru Marginean // Copyright (c) 2005 Joshua Lehrer // // Permission to use, copy, modify, distribute and sell this software for any // purpose is hereby granted without fee, provided that the above copyright // notice appear in all copies and that both that copyright notice and this // permission notice appear in supporting documentation. // The author makes no representations about the // suitability of this software for any purpose. It is provided "as is" // without express or implied warranty. //////////////////////////////////////////////////////////////////////////////// #ifndef LOKI_SCOPEGUARD_INC_ #define LOKI_SCOPEGUARD_INC_ // $Id$ #include // needed for calls to uncaught_exception. #include /// \defgroup ExceptionGroup Exception-safe code namespace Loki { //////////////////////////////////////////////////////////////// /// /// \class ScopeGuardImplBase /// \ingroup ExceptionGroup /// /// Base class used by all ScopeGuard implementations. All commonly used /// functions are in this class (e.g. - Dismiss and SafeExecute). /// /// See Andrei's and Petru Marginean's CUJ article /// http://www.cuj.com/documents/s=8000/cujcexp1812alexandr/alexandr.htm /// /// Changes to the original code by Joshua Lehrer: /// http://www.lehrerfamily.com/scopeguard.html //////////////////////////////////////////////////////////////// class ScopeGuardImplBase { public: enum ExceptionPolicy { AlwaysExecute = 0, CallIfNoException = 1, CallIfException = 2 }; ScopeGuardImplBase() throw() : dismissed_(false), exceptionPolicy_( AlwaysExecute ) {} void Dismiss() const throw() { dismissed_ = true; } void SetExceptionPolicy( ExceptionPolicy policy ) const throw() { exceptionPolicy_ = policy; } private: /// Copy-assignment operator is not implemented and private. ScopeGuardImplBase& operator =(const ScopeGuardImplBase&); protected: ~ScopeGuardImplBase() {} /// Copy-constructor takes over responsibility from other ScopeGuard. ScopeGuardImplBase(const ScopeGuardImplBase& other) throw() : dismissed_(other.dismissed_) , exceptionPolicy_( other.exceptionPolicy_ ) { other.Dismiss(); } template static void SafeExecute(J& j) throw() { if ( AlwaysExecute != j.exceptionPolicy_ ) { const bool anyThrown = ::std::uncaught_exception(); if ( anyThrown ) { if ( CallIfNoException == j.exceptionPolicy_ ) j.Dismiss(); } else if ( CallIfException == j.exceptionPolicy_ ) { j.Dismiss(); } } if (!j.dismissed_) { try { j.Execute(); } catch(...) {} } } mutable bool dismissed_; mutable ExceptionPolicy exceptionPolicy_; }; //////////////////////////////////////////////////////////////// /// /// \typedef typedef const ScopeGuardImplBase& ScopeGuard /// \ingroup ExceptionGroup /// //////////////////////////////////////////////////////////////// typedef const ScopeGuardImplBase& ScopeGuard; //////////////////////////////////////////////////////////////// /// /// \class ScopeGuardImpl0 /// \ingroup ExceptionGroup /// /// Implementation class for a standalone function or class static function /// with no parameters. ScopeGuard ignores any value returned from the /// call within the Execute function. /// /// This class has a single standalone helper function, MakeGuard which /// creates and returns a ScopeGuard. /// //////////////////////////////////////////////////////////////// template class ScopeGuardImpl0 : public ScopeGuardImplBase { public: static ScopeGuardImpl0 MakeGuard(F fun) { return ScopeGuardImpl0(fun); } ~ScopeGuardImpl0() throw() { SafeExecute(*this); } void Execute() { fun_(); } protected: ScopeGuardImpl0(F fun) : fun_(fun) {} F fun_; }; template inline ScopeGuardImpl0 MakeGuard(F fun) { return ScopeGuardImpl0::MakeGuard(fun); } //////////////////////////////////////////////////////////////// /// /// \class ScopeGuardImpl1 /// \ingroup ExceptionGroup /// /// Implementation class for a standalone function or class static function /// with one parameter. Each parameter is copied by value - use /// ::Loki::ByRef if you must use a reference instead. ScopeGuard ignores /// any value returned from the call within the Execute function. /// /// This class has a single standalone helper function, MakeGuard which /// creates and returns a ScopeGuard. /// //////////////////////////////////////////////////////////////// template class ScopeGuardImpl1 : public ScopeGuardImplBase { public: static ScopeGuardImpl1 MakeGuard(F fun, P1 p1) { return ScopeGuardImpl1(fun, p1); } ~ScopeGuardImpl1() throw() { SafeExecute(*this); } void Execute() { fun_(p1_); } protected: ScopeGuardImpl1(F fun, P1 p1) : fun_(fun), p1_(p1) {} F fun_; const P1 p1_; }; template inline ScopeGuardImpl1 MakeGuard(F fun, P1 p1) { return ScopeGuardImpl1::MakeGuard(fun, p1); } //////////////////////////////////////////////////////////////// /// /// \class ScopeGuardImpl2 /// \ingroup ExceptionGroup /// /// Implementation class for a standalone function or class static function /// with two parameters. Each parameter is copied by value - use /// ::Loki::ByRef if you must use a reference instead. ScopeGuard ignores /// any value returned from the call within the Execute function. /// /// This class has a single standalone helper function, MakeGuard which /// creates and returns a ScopeGuard. /// //////////////////////////////////////////////////////////////// template class ScopeGuardImpl2: public ScopeGuardImplBase { public: static ScopeGuardImpl2 MakeGuard(F fun, P1 p1, P2 p2) { return ScopeGuardImpl2(fun, p1, p2); } ~ScopeGuardImpl2() throw() { SafeExecute(*this); } void Execute() { fun_(p1_, p2_); } protected: ScopeGuardImpl2(F fun, P1 p1, P2 p2) : fun_(fun), p1_(p1), p2_(p2) {} F fun_; const P1 p1_; const P2 p2_; }; template inline ScopeGuardImpl2 MakeGuard(F fun, P1 p1, P2 p2) { return ScopeGuardImpl2::MakeGuard(fun, p1, p2); } //////////////////////////////////////////////////////////////// /// /// \class ScopeGuardImpl3 /// \ingroup ExceptionGroup /// /// Implementation class for a standalone function or class static function /// with three parameters. Each parameter is copied by value - use /// ::Loki::ByRef if you must use a reference instead. ScopeGuard ignores /// any value returned from the call within the Execute function. /// /// This class has a single standalone helper function, MakeGuard which /// creates and returns a ScopeGuard. /// //////////////////////////////////////////////////////////////// template class ScopeGuardImpl3 : public ScopeGuardImplBase { public: static ScopeGuardImpl3 MakeGuard(F fun, P1 p1, P2 p2, P3 p3) { return ScopeGuardImpl3(fun, p1, p2, p3); } ~ScopeGuardImpl3() throw() { SafeExecute(*this); } void Execute() { fun_(p1_, p2_, p3_); } protected: ScopeGuardImpl3(F fun, P1 p1, P2 p2, P3 p3) : fun_(fun), p1_(p1), p2_(p2), p3_(p3) {} F fun_; const P1 p1_; const P2 p2_; const P3 p3_; }; template inline ScopeGuardImpl3 MakeGuard(F fun, P1 p1, P2 p2, P3 p3) { return ScopeGuardImpl3::MakeGuard(fun, p1, p2, p3); } //////////////////////////////////////////////////////////////// /// /// \class ScopeGuardImpl4 /// \ingroup ExceptionGroup /// /// Implementation class for a standalone function or class static function /// with four parameters. Each parameter is copied by value - use /// ::Loki::ByRef if you must use a reference instead. ScopeGuard ignores /// any value returned from the call within the Execute function. /// /// This class has a single standalone helper function, MakeGuard which /// creates and returns a ScopeGuard. /// //////////////////////////////////////////////////////////////// template < typename F, typename P1, typename P2, typename P3, typename P4 > class ScopeGuardImpl4 : public ScopeGuardImplBase { public: static ScopeGuardImpl4< F, P1, P2, P3, P4 > MakeGuard( F fun, P1 p1, P2 p2, P3 p3, P4 p4 ) { return ScopeGuardImpl4< F, P1, P2, P3, P4 >( fun, p1, p2, p3, p4 ); } ~ScopeGuardImpl4() throw() { SafeExecute( *this ); } void Execute() { fun_( p1_, p2_, p3_, p4_ ); } protected: ScopeGuardImpl4( F fun, P1 p1, P2 p2, P3 p3, P4 p4 ) : fun_( fun ), p1_( p1 ), p2_( p2 ), p3_( p3 ), p4_( p4 ) {} F fun_; const P1 p1_; const P2 p2_; const P3 p3_; const P4 p4_; }; template < typename F, typename P1, typename P2, typename P3, typename P4 > inline ScopeGuardImpl4< F, P1, P2, P3, P4 > MakeGuard( F fun, P1 p1, P2 p2, P3 p3, P4 p4 ) { return ScopeGuardImpl4< F, P1, P2, P3, P4 >::MakeGuard( fun, p1, p2, p3, p4 ); } //////////////////////////////////////////////////////////////// /// /// \class ScopeGuardImpl5 /// \ingroup ExceptionGroup /// /// Implementation class for a standalone function or class static function /// with five parameters. Each parameter is copied by value - use /// ::Loki::ByRef if you must use a reference instead. ScopeGuard ignores /// any value returned from the call within the Execute function. /// /// This class has a single standalone helper function, MakeGuard which /// creates and returns a ScopeGuard. /// //////////////////////////////////////////////////////////////// template < typename F, typename P1, typename P2, typename P3, typename P4, typename P5 > class ScopeGuardImpl5 : public ScopeGuardImplBase { public: static ScopeGuardImpl5< F, P1, P2, P3, P4, P5 > MakeGuard( F fun, P1 p1, P2 p2, P3 p3, P4 p4, P5 p5 ) { return ScopeGuardImpl5< F, P1, P2, P3, P4, P5 >( fun, p1, p2, p3, p4, p5 ); } ~ScopeGuardImpl5() throw() { SafeExecute( *this ); } void Execute() { fun_( p1_, p2_, p3_, p4_, p5_ ); } protected: ScopeGuardImpl5( F fun, P1 p1, P2 p2, P3 p3, P4 p4, P5 p5 ) : fun_( fun ), p1_( p1 ), p2_( p2 ), p3_( p3 ), p4_( p4 ), p5_( p5 ) {} F fun_; const P1 p1_; const P2 p2_; const P3 p3_; const P4 p4_; const P5 p5_; }; template < typename F, typename P1, typename P2, typename P3, typename P4, typename P5 > inline ScopeGuardImpl5< F, P1, P2, P3, P4, P5 > MakeGuard( F fun, P1 p1, P2 p2, P3 p3, P4 p4, P5 p5 ) { return ScopeGuardImpl5< F, P1, P2, P3, P4, P5 >::MakeGuard( fun, p1, p2, p3, p4, p5 ); } //////////////////////////////////////////////////////////////// /// /// \class ObjScopeGuardImpl0 /// \ingroup ExceptionGroup /// /// Implementation class for a class per-instance member function with no /// parameters. ScopeGuard ignores any value returned from the call within /// the Execute function. /// /// This class has 3 standalone helper functions which create a ScopeGuard. /// One is MakeObjGuard, which is deprecated but provided for older code. /// The other two are MakeGuard overloads, one which takes a pointer to an /// object, and the other which takes a reference. /// //////////////////////////////////////////////////////////////// template class ObjScopeGuardImpl0 : public ScopeGuardImplBase { public: static ObjScopeGuardImpl0 MakeObjGuard(Obj& obj, MemFun memFun) { return ObjScopeGuardImpl0(obj, memFun); } ~ObjScopeGuardImpl0() throw() { SafeExecute(*this); } void Execute() { (obj_.*memFun_)(); } protected: ObjScopeGuardImpl0(Obj& obj, MemFun memFun) : obj_(obj), memFun_(memFun) {} Obj& obj_; MemFun memFun_; }; template inline ObjScopeGuardImpl0 MakeObjGuard(Obj& obj, MemFun memFun) { return ObjScopeGuardImpl0::MakeObjGuard(obj, memFun); } template inline ObjScopeGuardImpl0 MakeGuard(Ret(Obj2::*memFun)(), Obj1 &obj) { return ObjScopeGuardImpl0::MakeObjGuard(obj,memFun); } template inline ObjScopeGuardImpl0 MakeGuard(Ret(Obj2::*memFun)(), Obj1 *obj) { return ObjScopeGuardImpl0::MakeObjGuard(*obj,memFun); } //////////////////////////////////////////////////////////////// /// /// \class ObjScopeGuardImpl1 /// \ingroup ExceptionGroup /// /// Implementation class for a class per-instance member function with one /// parameter. The parameter is copied by value - use ::Loki::ByRef if you /// must use a reference instead. ScopeGuard ignores any value returned /// from the call within the Execute function. /// /// This class has 3 standalone helper functions which create a ScopeGuard. /// One is MakeObjGuard, which is deprecated but provided for older code. /// The other two are MakeGuard overloads, one which takes a pointer to an /// object, and the other which takes a reference. /// //////////////////////////////////////////////////////////////// template class ObjScopeGuardImpl1 : public ScopeGuardImplBase { public: static ObjScopeGuardImpl1 MakeObjGuard(Obj& obj, MemFun memFun, P1 p1) { return ObjScopeGuardImpl1(obj, memFun, p1); } ~ObjScopeGuardImpl1() throw() { SafeExecute(*this); } void Execute() { (obj_.*memFun_)(p1_); } protected: ObjScopeGuardImpl1(Obj& obj, MemFun memFun, P1 p1) : obj_(obj), memFun_(memFun), p1_(p1) {} Obj& obj_; MemFun memFun_; const P1 p1_; }; template inline ObjScopeGuardImpl1 MakeObjGuard(Obj& obj, MemFun memFun, P1 p1) { return ObjScopeGuardImpl1::MakeObjGuard(obj, memFun, p1); } template inline ObjScopeGuardImpl1 MakeGuard(Ret(Obj2::*memFun)(P1a), Obj1 &obj, P1b p1) { return ObjScopeGuardImpl1::MakeObjGuard(obj,memFun,p1); } template inline ObjScopeGuardImpl1 MakeGuard(Ret(Obj2::*memFun)(P1a), Obj1 *obj, P1b p1) { return ObjScopeGuardImpl1::MakeObjGuard(*obj,memFun,p1); } //////////////////////////////////////////////////////////////// /// /// \class ObjScopeGuardImpl2 /// \ingroup ExceptionGroup /// /// Implementation class for a class per-instance member function with two /// parameters. Each parameter is copied by value - use ::Loki::ByRef if you /// must use a reference instead. ScopeGuard ignores any value returned /// from the call within the Execute function. /// /// This class has 3 standalone helper functions which create a ScopeGuard. /// One is MakeObjGuard, which is deprecated but provided for older code. /// The other two are MakeGuard overloads, one which takes a pointer to an /// object, and the other which takes a reference. /// //////////////////////////////////////////////////////////////// template class ObjScopeGuardImpl2 : public ScopeGuardImplBase { public: static ObjScopeGuardImpl2 MakeObjGuard(Obj& obj, MemFun memFun, P1 p1, P2 p2) { return ObjScopeGuardImpl2(obj, memFun, p1, p2); } ~ObjScopeGuardImpl2() throw() { SafeExecute(*this); } void Execute() { (obj_.*memFun_)(p1_, p2_); } protected: ObjScopeGuardImpl2(Obj& obj, MemFun memFun, P1 p1, P2 p2) : obj_(obj), memFun_(memFun), p1_(p1), p2_(p2) {} Obj& obj_; MemFun memFun_; const P1 p1_; const P2 p2_; }; template inline ObjScopeGuardImpl2 MakeObjGuard(Obj& obj, MemFun memFun, P1 p1, P2 p2) { return ObjScopeGuardImpl2::MakeObjGuard(obj, memFun, p1, p2); } template inline ObjScopeGuardImpl2 MakeGuard(Ret(Obj2::*memFun)(P1a,P2a), Obj1 &obj, P1b p1, P2b p2) { return ObjScopeGuardImpl2::MakeObjGuard(obj,memFun,p1,p2); } template inline ObjScopeGuardImpl2 MakeGuard(Ret(Obj2::*memFun)(P1a,P2a), Obj1 *obj, P1b p1, P2b p2) { return ObjScopeGuardImpl2::MakeObjGuard(*obj,memFun,p1,p2); } //////////////////////////////////////////////////////////////// /// /// \class ObjScopeGuardImpl3 /// \ingroup ExceptionGroup /// /// Implementation class for a class per-instance member function with three /// parameters. Each parameter is copied by value - use ::Loki::ByRef if you /// must use a reference instead. ScopeGuard ignores any value returned /// from the call within the Execute function. /// /// This class has 3 standalone helper functions which create a ScopeGuard. /// One is MakeObjGuard, which is deprecated but provided for older code. /// The other two are MakeGuard overloads, one which takes a pointer to an /// object, and the other which takes a reference. /// //////////////////////////////////////////////////////////////// template < class Obj, typename MemFun, typename P1, typename P2, typename P3 > class ObjScopeGuardImpl3 : public ScopeGuardImplBase { public: static ObjScopeGuardImpl3< Obj, MemFun, P1, P2, P3 > MakeObjGuard( Obj & obj, MemFun memFun, P1 p1, P2 p2, P3 p3 ) { return ObjScopeGuardImpl3< Obj, MemFun, P1, P2, P3 >( obj, memFun, p1, p2, p3 ); } ~ObjScopeGuardImpl3() throw() { SafeExecute( *this ); } void Execute() { ( obj_.*memFun_ )( p1_, p2_, p3_ ); } protected: ObjScopeGuardImpl3( Obj & obj, MemFun memFun, P1 p1, P2 p2, P3 p3 ) : obj_( obj ), memFun_( memFun ), p1_( p1 ), p2_( p2 ), p3_( p3 ) {} Obj& obj_; MemFun memFun_; const P1 p1_; const P2 p2_; const P3 p3_; }; template < class Obj, typename MemFun, typename P1, typename P2, typename P3 > inline ObjScopeGuardImpl3< Obj, MemFun, P1, P2, P3 > MakeObjGuard( Obj & obj, MemFun memFun, P1 p1, P2 p2, P3 p3 ) { return ObjScopeGuardImpl3< Obj, MemFun, P1, P2, P3 >::MakeObjGuard( obj, memFun, p1, p2, p3 ); } template < typename Ret, class Obj1, class Obj2, typename P1a, typename P1b, typename P2a, typename P2b, typename P3a, typename P3b > inline ObjScopeGuardImpl3< Obj1, Ret( Obj2::* )( P1a, P2a, P3a ), P1b, P2b, P3b > MakeGuard( Ret( Obj2::*memFun )( P1a, P2a, P3a ), Obj1 & obj, P1b p1, P2b p2, P3b p3 ) { return ObjScopeGuardImpl3< Obj1, Ret( Obj2::* )( P1a, P2a, P3a ), P1b, P2b, P3b > ::MakeObjGuard( obj, memFun, p1, p2, p3 ); } template < typename Ret, class Obj1, class Obj2, typename P1a, typename P1b, typename P2a, typename P2b, typename P3a, typename P3b > inline ObjScopeGuardImpl3< Obj1, Ret( Obj2::* )( P1a, P2a, P3a ), P1b, P2b, P3b > MakeGuard( Ret( Obj2::*memFun )( P1a, P2a, P3a ), Obj1 * obj, P1b p1, P2b p2, P3b p3 ) { return ObjScopeGuardImpl3< Obj1, Ret( Obj2::* )( P1a, P2a, P3a ), P1b, P2b, P3b > ::MakeObjGuard( *obj, memFun, p1, p2, p3 ); } } // namespace Loki #define LOKI_CONCATENATE_DIRECT(s1, s2) s1##s2 #define LOKI_CONCATENATE(s1, s2) LOKI_CONCATENATE_DIRECT(s1, s2) #define LOKI_ANONYMOUS_VARIABLE(str) LOKI_CONCATENATE(str, __LINE__) #define LOKI_ON_BLOCK_EXIT ::Loki::ScopeGuard LOKI_ANONYMOUS_VARIABLE(scopeGuard) = ::Loki::MakeGuard #define LOKI_ON_BLOCK_EXIT_OBJ ::Loki::ScopeGuard LOKI_ANONYMOUS_VARIABLE(scopeGuard) = ::Loki::MakeObjGuard #endif // end file guardian