Source code of Windows XP (NT5)
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//+-------------------------------------------------------------------------
//
// Copyright (C) 1992, Microsoft Corporation.
//
// File: safepnt.hxx
//
// Contents: Safe pointers to interfaces and to memory
//
// Classes:
//
// Functions:
//
// History: 03-Mar-93 KevinRo Created
// 07-Jul-94 MikeSe Rationalised with smartp.hxx
// 19-Jul-94 KirtD Added SAFE_XXX_HANDLE
// 03-Aug-93 DrewB/AdamS Added Set/Attach/Detach
// 16-Oct-93 DrewB Added non-Cairo support
//
// Notes:
//
// This file contains a set of macros that define safe pointers to various
// classes of memory. Memory that is reference counted (such as interfaces),
// memory allocated using MemAlloc/MemFree, and memory allocated from
// the local heap. The classes handle both pointers to structures and memory
// by having versions that include the -> operator, or not.
//
//--------------------------------------------------------------------------
#ifndef _SAFEPNT_HXX_
#define _SAFEPNT_HXX_
#include <except.hxx>
#include <debnot.h>
//+-------------------------------------------------------------------------
//
// The basic usage for all of these macros is:
//
// SAFE_xxx_PTR( NameOfSafePointerClass, TypeOfDataPointedTo)
//
// Each invocation of such macro declares a new class of the specified name
// whose only member variable is a pointer (called the captured pointer)
// to the specified type, and whose behaviour is largely indistiguishable from
// a regular pointer to that type, except that it is leak-free (if used
// correctly).
//
// For example, SAFE_INTERFACE_PTR( SafeUnknown, IUnknown)
// SAFE_HEAP_MEMPTR( SafeWCHARPtr, WCHAR )
//
// The captured pointer is generally acquired during construction of the
// safe pointer class, and acquisition may include invoking an operation on
// the captured pointer.
//
// In addition, the pointer may be captured by being the output of a function
// call. This is the only intended purpose of the & operator provided by
// the safe pointer class.
//
// When the safe pointer instance go out of scope (either normally or as
// the result of an exception), the captured pointer is "freed" by invoking
// an appropriate operation on it.
//
// The captured pointer may be passed on elsewhere using the Transfer method
// in which case destruction of the safe pointer becomes a nop. In particular
// this can be used to tranfer the captured pointer from one safe pointer to
// another, viz:
//
// sp1.Transfer ( &sp2 );
//
// The Transfer method is implemented in such a way that an exception on the
// output pointer will not result in a leak.
//
// Safe pointers are intended to be used as resource containers. To that end,
// the list of operators available is intentionally short. However, based on
// experience, safe pointers can be used in most places that a normal
// pointer would be used. The exception is that safe pointers do not allow
// for arithmetic operations. For example:
//
// SpWCHARPtr spwz(new WCHAR[10]);
//
// spwz++; // Not allowed, since the pointer would change.
//
// wcscpy(spwz,L"Test"); // This is OK
//
//--------------------------------------------------------------------------
//+-------------------------------------------------------------------------
//
// Macro: SAFE_INTERFACE_PTR
//
// Purpose: Safe pointer to any interface that supports AddRef/Release
//
// Notes: This works for classes that define AddRef/Release, or for
// Cairole interfaces. It is not necessary that the class
// be a derivative of IUnknown, so long as it supports
// AddRef and Release methods which have the same semantics as
// those in IUnknown.
//
// The constructor takes a parameter which specifies whether
// the captured pointer should be AddRef'd, defaulting to TRUE.
//
// The Copy function creates a valid additional copy of
// the captured pointer (following the AddRef/Release protocol)
// so can be used to hand out copies from a safe pointer declared
// as a member of some other class.
//
//--------------------------------------------------------------------------
#define SAFE_INTERFACE_PTR(SpName,SpType) \
class SpName INHERIT_UNWIND_IF_CAIRO \
{ \
INLINE_UNWIND(SpName) \
public: \
\
inline SpName ( SpType * pinter=NULL,BOOL fInc=TRUE) \
: _p ( pinter ) \
{ \
if (fInc && (_p != NULL)) \
{ \
_p->AddRef(); \
} \
END_CONSTRUCTION (SpName) \
} \
\
inline ~##SpName () \
{ \
if (_p != NULL) \
{ \
_p->Release(); \
_p = NULL; \
} \
} \
\
inline void Transfer ( SpType **pxtmp) \
{ \
*pxtmp = _p; \
_p = NULL; \
} \
inline void Copy ( SpType **pxtmp) \
{ \
*pxtmp = _p; \
if (_p != NULL) \
_p->AddRef(); \
} \
inline void Set(SpType* p, BOOL fInc = TRUE) \
{ \
if (_p) \
{ \
_p->Release(); \
} \
_p = p; \
if (fInc && _p) \
{ \
_p->AddRef(); \
} \
} \
inline void Attach(SpType* p) \
{ \
Win4Assert(_p == NULL); \
_p = p; \
} \
inline void Detach(void) \
{ \
_p = NULL; \
} \
\
inline SpType * operator-> () { return _p; } \
inline SpType& operator * () { return *_p; } \
inline operator SpType *() { return _p; } \
inline SpType ** operator &() \
{ \
Win4Assert ( _p == NULL ); \
return &_p; \
} \
\
inline SpType *Self(void) { return _p; } \
\
private: \
SpType * _p; \
inline void operator = (const SpName &) {;} \
inline SpName ( const SpName &){;} \
};
//+-------------------------------------------------------------------------
//
// Macro: TRANSFER_INTERFACE
//
// Purpose: Transfers a specific interface from a safe object to an
// interface pointer. Simple Transfer doesn't always work right
// for safe objects that implement multiple interfaces; this
// macro must be used
//
// Usage:
// IStorage *pstg;
// SafeFoo sfoo;
// TRANSFER_INTERFACE(sfoo, IStorage, &pstg)
//
//--------------------------------------------------------------------------
#define TRANSFER_INTERFACE(smart, iface, ppiface) \
(*(ppiface) = (iface *)((smart).Self()), (smart).Detach())
//+-------------------------------------------------------------------------
//
// Macro: SAFE_MEMALLOC_PTR
//
// Purpose: Pointer to memory created by MemAlloc. Supports the
// -> operator. Can point to a structure.
//
//--------------------------------------------------------------------------
// Cairo only
#if WIN32 == 300
#define SAFE_MEMALLOC_PTR(SpName,SpType) \
class SpName INHERIT_UNWIND_IF_CAIRO \
{ \
INLINE_UNWIND(SpName) \
public: \
inline SpName ( SpType * pinter=NULL) \
: _p ( pinter ) \
{ \
END_CONSTRUCTION (SpName) \
} \
\
inline ~##SpName () \
{ \
MemFree(_p); \
_p = NULL; \
} \
inline void Transfer ( SpType **pxtmp) \
{ \
*pxtmp = _p; \
_p = NULL; \
} \
inline void Set(SpType* p) \
{ \
MemFree(_p); \
_p = p; \
} \
inline void Attach(SpType* p) \
{ \
Win4Assert(_p == NULL); \
_p = p; \
} \
inline void Detach(void) \
{ \
_p = NULL; \
} \
\
inline SpType * operator-> () { return _p; } \
inline SpType & operator * () { return *_p; } \
inline operator SpType *() { return _p; } \
inline SpType ** operator &() \
{ \
Win4Assert ( _p == NULL ); \
return &_p; \
} \
\
private: \
SpType * _p; \
inline void operator = (const SpName &) {;} \
inline SpName ( const SpName &){;} \
};
//+-------------------------------------------------------------------------
//
// Macro: SAFE_MEMALLOC_MEMPTR
//
// Purpose: Pointer to memory created by MemAlloc. This class does
// not supply a -> operator. Therefore, structure or class
// members are not available.
//
//--------------------------------------------------------------------------
#define SAFE_MEMALLOC_MEMPTR(SpName,SpType) \
class SpName INHERIT_UNWIND_IF_CAIRO \
{ \
INLINE_UNWIND(SpName) \
public: \
inline SpName ( SpType * pinter=NULL) \
: _p ( pinter ) \
{ \
END_CONSTRUCTION (SpName) \
} \
\
inline ~##SpName () \
{ \
MemFree(_p); \
_p = NULL; \
} \
inline void Transfer ( SpType **pxtmp) \
{ \
*pxtmp = _p; \
_p = NULL; \
} \
inline void Set(SpType* p) \
{ \
MemFree(_p); \
_p = p; \
} \
inline void Attach(SpType* p) \
{ \
Win4Assert(_p == NULL); \
_p = p; \
} \
inline void Detach(void) \
{ \
_p = NULL; \
} \
\
inline SpType & operator * () { return *_p; } \
inline operator SpType *() { return _p; } \
inline SpType ** operator &() \
{ \
Win4Assert ( _p == NULL ); \
return &_p; \
} \
\
private: \
SpType * _p; \
inline void operator = (const SpName &) {;} \
inline SpName ( const SpName &){;} \
};
#endif // Cairo
//+-------------------------------------------------------------------------
//
// Macro: SAFE_COMEMALLOC_PTR
//
// Purpose: Pointer to memory created by COMEMALLOC. Supports the
// -> operator. Can point to a structure.
//
//--------------------------------------------------------------------------
#define SAFE_COMEMALLOC_PTR(SpName,SpType) \
class SpName INHERIT_UNWIND_IF_CAIRO \
{ \
INLINE_UNWIND(SpName) \
public: \
inline SpName ( SpType * pinter=NULL) \
: _p ( pinter ) \
{ \
END_CONSTRUCTION (SpName) \
} \
\
inline ~##SpName () \
{ \
CoMemFree(_p); \
_p = NULL; \
} \
inline void Transfer ( SpType **pxtmp) \
{ \
*pxtmp = _p; \
_p = NULL; \
} \
inline void Set(SpType* p) \
{ \
CoMemFree(_p); \
_p = p; \
} \
inline void Attach(SpType* p) \
{ \
Win4Assert(_p == NULL); \
_p = p; \
} \
inline void Detach(void) \
{ \
_p = NULL; \
} \
\
inline SpType * operator-> () { return _p; } \
inline SpType & operator * () { return *_p; } \
inline operator SpType *() { return _p; } \
inline SpType ** operator &() \
{ \
Win4Assert ( _p == NULL ); \
return &_p; \
} \
\
private: \
SpType * _p; \
inline void operator = (const SpName &) {;} \
inline SpName ( const SpName &){;} \
};
//+-------------------------------------------------------------------------
//
// Macro: SAFE_COMEMALLOC_MEMPTR
//
// Purpose: Pointer to memory created by COMEMALLOC. This class does
// not supply a -> operator. Therefore, structure or class
// members are not available.
//
//--------------------------------------------------------------------------
#define SAFE_COMEMALLOC_MEMPTR(SpName,SpType) \
class SpName INHERIT_UNWIND_IF_CAIRO \
{ \
INLINE_UNWIND(SpName) \
public: \
inline SpName ( SpType * pinter=NULL) \
: _p ( pinter ) \
{ \
END_CONSTRUCTION (SpName) \
} \
\
inline ~##SpName () \
{ \
CoMemFree(_p); \
_p = NULL; \
} \
inline void Transfer ( SpType **pxtmp) \
{ \
*pxtmp = _p; \
_p = NULL; \
} \
inline void Set(SpType* p) \
{ \
CoMemFree(_p); \
_p = p; \
} \
inline void Attach(SpType* p) \
{ \
Win4Assert(_p == NULL); \
_p = p; \
} \
inline void Detach(void) \
{ \
_p = NULL; \
} \
\
inline SpType & operator * () { return *_p; } \
inline operator SpType *() { return _p; } \
inline SpType ** operator &() \
{ \
Win4Assert ( _p == NULL ); \
return &_p; \
} \
\
private: \
SpType * _p; \
inline void operator = (const SpName &) {;} \
inline SpName ( const SpName &){;} \
};
//+-------------------------------------------------------------------------
//
// Macro: SAFE_HEAP_PTR
//
// Purpose: Pointer to memory created by operator new. Supports the
// -> operator. Can point to a structure.
//
//--------------------------------------------------------------------------
#define SAFE_HEAP_PTR(SpName,SpType) \
class SpName INHERIT_UNWIND_IF_CAIRO \
{ \
INLINE_UNWIND(SpName) \
public: \
inline SpName ( SpType * pinter=NULL) \
: _p ( pinter ) \
{ \
END_CONSTRUCTION (SpName) \
} \
\
inline ~##SpName () \
{ \
delete _p; \
_p = NULL; \
} \
inline void Transfer ( SpType **pxtmp) \
{ \
*pxtmp = _p; \
_p = NULL; \
} \
inline void Set(SpType* p) \
{ \
delete _p; \
_p = p; \
} \
inline void Attach(SpType* p) \
{ \
Win4Assert(_p == NULL); \
_p = p; \
} \
inline void Detach(void) \
{ \
_p = NULL; \
} \
\
inline SpType * operator-> () { return _p; } \
inline SpType & operator * () { return *_p; } \
inline operator SpType *() { return _p; } \
inline SpType ** operator &() \
{ \
Win4Assert ( _p == NULL ); \
return &_p; \
} \
\
private: \
SpType * _p; \
inline void operator = (const SpName &) {;} \
inline SpName ( const SpName &){;} \
};
//+-------------------------------------------------------------------------
//
// Macro: SAFE_HEAP_MEMPTR
//
// Purpose: Pointer to memory created by operator new. This class does
// not supply a -> operator. Therefore, structure or class
// members are not available.
//
//--------------------------------------------------------------------------
#define SAFE_HEAP_MEMPTR(SpName,SpType) \
class SpName INHERIT_UNWIND_IF_CAIRO \
{ \
INLINE_UNWIND(SpName) \
public: \
inline SpName ( SpType * pinter=NULL) \
: _p ( pinter ) \
{ \
END_CONSTRUCTION (SpName) \
} \
\
inline ~##SpName () \
{ \
delete _p; \
_p = NULL; \
} \
inline void Transfer ( SpType **pxtmp) \
{ \
*pxtmp = _p; \
_p = NULL; \
} \
inline void Set(SpType* p) \
{ \
delete _p; \
_p = p; \
} \
inline void Attach(SpType* p) \
{ \
Win4Assert(_p == NULL); \
_p = p; \
} \
inline void Detach(void) \
{ \
_p = NULL; \
} \
\
inline SpType & operator * () { return *_p; } \
inline operator SpType *() { return _p; } \
inline SpType ** operator &() \
{ \
Win4Assert ( _p == NULL ); \
return &_p; \
} \
\
private: \
SpType * _p; \
inline void operator = (const SpName &) {;} \
inline SpName ( const SpName &){;} \
};
//+-------------------------------------------------------------------------
//
// Macro: SAFE_XXX_HANDLE
//
// Purpose: Smart resource to a WIN 32, WIN 32 Find or NT HANDLE.
//
// Usage: SAFE_WIN32_HANDLE(XWIN32Handle)
// SAFE_WIN32FIND_HANDLE(XWIN32FindHandle)
// SAFE_NT_HANDLE(XNtHandle)
//
//--------------------------------------------------------------------------
#ifdef WIN32
#define SAFE_WIN32_HANDLE(ShName) \
\
class ShName INHERIT_UNWIND_IF_CAIRO \
{ \
INLINE_UNWIND(ShName) \
public: \
\
inline ShName (HANDLE handle = NULL) \
: _handle(handle) \
{ \
END_CONSTRUCTION(ShName) \
} \
\
inline ~##ShName () \
{ \
if ((_handle != INVALID_HANDLE_VALUE) && (_handle != NULL)) \
{ \
CloseHandle(_handle); \
} \
} \
\
inline void Transfer(HANDLE *phandle) \
{ \
*phandle = _handle; \
_handle = NULL; \
} \
inline void Set(HANDLE h) \
{ \
if (_handle != INVALID_HANDLE_VALUE && _handle != NULL) \
{ \
CloseHandle(_handle); \
} \
_handle = h; \
} \
inline void Attach(HANDLE h) \
{ \
Win4Assert(_handle == NULL); \
_handle = h; \
} \
inline void Detach(void) \
{ \
_handle = NULL; \
} \
\
inline operator HANDLE () \
{ \
return(_handle); \
} \
\
inline HANDLE operator= (HANDLE handle) \
{ \
Set(handle); \
return(_handle); \
} \
\
inline BOOL operator==(HANDLE handle) \
{ \
if (_handle == handle) \
{ \
return(TRUE); \
} \
return(FALSE); \
} \
\
inline HANDLE *operator&() \
{ \
Win4Assert((_handle==NULL) || (_handle==INVALID_HANDLE_VALUE));\
return(&_handle); \
} \
\
private: \
\
HANDLE _handle; \
\
inline VOID operator= (const ShName &) {;} \
inline ShName (const ShName &) {;} \
\
};
#define SAFE_WIN32FIND_HANDLE(ShName) \
\
class ShName INHERIT_UNWIND_IF_CAIRO \
{ \
INLINE_UNWIND(ShName) \
public: \
\
inline ShName (HANDLE handle = NULL) \
: _handle(handle) \
{ \
END_CONSTRUCTION(ShName) \
} \
\
inline ~##ShName () \
{ \
if ((_handle != INVALID_HANDLE_VALUE) && (_handle != NULL)) \
{ \
FindClose(_handle); \
} \
} \
\
inline void Transfer(HANDLE *phandle) \
{ \
*phandle = _handle; \
_handle = NULL; \
} \
inline void Set(HANDLE h) \
{ \
if (_handle != INVALID_HANDLE_VALUE && _handle != NULL) \
{ \
FindClose(_handle); \
} \
_handle = h; \
} \
inline void Attach(HANDLE h) \
{ \
Win4Assert(_handle == NULL); \
_handle = h; \
} \
inline void Detach(void) \
{ \
_handle = NULL; \
} \
\
inline operator HANDLE () \
{ \
return(_handle); \
} \
\
inline HANDLE operator= (HANDLE handle) \
{ \
Set(handle); \
return(_handle); \
} \
\
inline BOOL operator==(HANDLE handle) \
{ \
if (_handle == handle) \
{ \
return(TRUE); \
} \
return(FALSE); \
} \
\
inline HANDLE *operator&() \
{ \
Win4Assert((_handle==NULL) || (_handle==INVALID_HANDLE_VALUE));\
return(&_handle); \
} \
\
private: \
\
HANDLE _handle; \
\
inline VOID operator= (const ShName &) {;} \
inline ShName (const ShName &) {;} \
\
};
#endif // WIN32
// Only available on NT platforms
#if WIN32 == 100 || WIN32 == 300
#define SAFE_NT_HANDLE(ShName) \
\
class ShName INHERIT_UNWIND_IF_CAIRO \
{ \
INLINE_UNWIND(ShName) \
public: \
\
inline ShName (HANDLE handle = NULL) \
: _handle(handle) \
{ \
END_CONSTRUCTION(ShName) \
} \
\
inline ~##ShName () \
{ \
if ((_handle != INVALID_HANDLE_VALUE) && (_handle != NULL)) \
{ \
NtClose(_handle); \
} \
} \
\
inline void Transfer(HANDLE *phandle) \
{ \
*phandle = _handle; \
_handle = NULL; \
} \
inline void Set(HANDLE h) \
{ \
if (_handle != INVALID_HANDLE_VALUE && _handle != NULL) \
{ \
NtClose(_handle); \
} \
_handle = h; \
} \
inline void Attach(HANDLE h) \
{ \
Win4Assert(_handle == NULL); \
_handle = h; \
} \
inline void Detach(void) \
{ \
_handle = NULL; \
} \
\
inline operator HANDLE () \
{ \
return(_handle); \
} \
\
inline HANDLE operator= (HANDLE handle) \
{ \
Set(handle); \
return(_handle); \
} \
\
inline BOOL operator==(HANDLE handle) \
{ \
if (_handle == handle) \
{ \
return(TRUE); \
} \
return(FALSE); \
} \
\
inline HANDLE *operator&() \
{ \
Win4Assert((_handle==NULL) || (_handle==INVALID_HANDLE_VALUE));\
return(&_handle); \
} \
\
private: \
\
HANDLE _handle; \
\
inline VOID operator= (const ShName &) {;} \
inline ShName (const ShName &) {;} \
\
};
#define SAFE_NT_HANDLE_NO_UNWIND(ShName) \
\
class ShName \
{ \
public: \
\
inline ShName (HANDLE handle = NULL) \
: _handle(handle) \
{ \
} \
\
inline ~##ShName () \
{ \
if ((_handle != INVALID_HANDLE_VALUE) && (_handle != NULL)) \
{ \
NtClose(_handle); \
} \
} \
\
inline void Transfer(HANDLE *phandle) \
{ \
*phandle = _handle; \
_handle = NULL; \
} \
inline void Set(HANDLE h) \
{ \
if (_handle != INVALID_HANDLE_VALUE && _handle != NULL) \
{ \
NtClose(_handle); \
} \
_handle = h; \
} \
inline void Attach(HANDLE h) \
{ \
Win4Assert(_handle == NULL); \
_handle = h; \
} \
inline void Detach(void) \
{ \
_handle = NULL; \
} \
\
inline operator HANDLE () \
{ \
return(_handle); \
} \
\
inline HANDLE operator= (HANDLE handle) \
{ \
Set(handle); \
return(_handle); \
} \
\
inline BOOL operator==(HANDLE handle) \
{ \
if (_handle == handle) \
{ \
return(TRUE); \
} \
return(FALSE); \
} \
\
inline HANDLE *operator&() \
{ \
Win4Assert((_handle==NULL) || (_handle==INVALID_HANDLE_VALUE));\
return(&_handle); \
} \
\
private: \
\
HANDLE _handle; \
\
inline VOID operator= (const ShName &) {;} \
inline ShName (const ShName &) {;} \
\
};
#endif // NT platforms
//+-------------------------------------------------------------------------
//
// UNWINDABLE_WRAPPER allows you to declare an unwindable wrapper class
// for an existing class to make it exception safe
//
// class Foo;
// UNWINDABLE_WRAPPER(SafeCFoo, CFoo);
//
// UNWINDABLE_WRAPPER_ARGS is an alternate form that allows arguments to
// the constructor
//
// class Foo;
// Foo::Foo(int foo);
// UNWINDABLE_WRAPPER_ARGS(SafeCFoo, CFoo, (int foo), (foo));
//
//--------------------------------------------------------------------------
// Cairo only
#if WIN32 == 300
#define UNWINDABLE_WRAPPER(UwName, Class) \
class UwName : INHERIT_UNWIND, public Class \
{ \
INLINE_UNWIND(UwName) \
public: \
inline UwName(void) \
{ \
END_CONSTRUCTION(UwName); \
} \
inline ~##UwName(void) \
{ \
} \
}
#define UNWINDABLE_WRAPPER_ARGS(UwName, Class, CtorDecl, CtorArgs) \
class UwName : INHERIT_UNWIND, public Class \
{ \
INLINE_UNWIND(UwName) \
public: \
inline UwName CtorDecl : Class CtorArgs \
{ \
END_CONSTRUCTION(UwName); \
} \
inline ~##UwName(void) \
{ \
} \
}
#endif // Cairo only
#endif // _SAFEPNT_HXX_