172 lines
5.4 KiB
C++
172 lines
5.4 KiB
C++
//+---------------------------------------------------------------------------
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//
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// Microsoft Windows
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// Copyright (C) Microsoft Corporation, 1996 - 2002.
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//
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// File : SMem.hxx
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//
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// Contents : Shared memory (named + file based)
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//
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// Classes : CNamedSharedMem
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//
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// History: 22-Mar-94 t-joshh Created
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//
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//----------------------------------------------------------------------------
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#pragma once
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#include <secutil.hxx>
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//+---------------------------------------------------------------------------
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//
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// Class: CNamedSharedMem
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//
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// Purpose: Named shared memory
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//
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// History: 22-Mar-94 t-joshh Created
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//
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//----------------------------------------------------------------------------
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class CNamedSharedMem
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{
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public:
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CNamedSharedMem()
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: _hMap( 0 ),
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_pb( 0 )
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{
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}
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enum eNameType { AppendPid };
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~CNamedSharedMem()
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{
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if ( 0 != _pb )
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UnmapViewOfFile( _pb );
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if ( 0 != _hMap )
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CloseHandle( _hMap );
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}
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BYTE * GetPointer() { return _pb; }
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BYTE * Get() { return _pb; }
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BOOL Ok() { return ( 0 != _pb ); }
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void CreateForWriteFromRegKey( WCHAR const * pwszName,
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ULONG cb,
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WCHAR const * pwcRegKey )
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{
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Win4Assert( 0 == _hMap );
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Win4Assert( 0 == _pb );
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Win4Assert( 0 != pwcRegKey );
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_hMap = CreateFileMapping( INVALID_HANDLE_VALUE, // Map to page file
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0, // Security attributes
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PAGE_READWRITE, // Page-level protection
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0, // Size high
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cb, // size low
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pwszName ); // Name
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if ( 0 == _hMap )
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THROW( CException() );
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DWORD dwErr = CopyNamedDacls( pwszName, pwcRegKey );
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if ( NO_ERROR != dwErr )
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THROW( CException( HRESULT_FROM_WIN32( dwErr ) ) );
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_pb = (BYTE *) MapViewOfFile( _hMap, // Handle to map
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FILE_MAP_WRITE, // Access
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0, // Offset (high)
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0, // Offset (low)
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0 ); // Map all
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if ( 0 == _pb )
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{
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DWORD dwErr = GetLastError();
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CloseHandle( _hMap );
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_hMap = 0;
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THROW( CException( HRESULT_FROM_WIN32( dwErr ) ) );
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}
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}
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void CreateForWriteFromSA( WCHAR const * pwszName,
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ULONG cb,
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SECURITY_ATTRIBUTES & sa )
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{
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Win4Assert( 0 == _hMap );
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Win4Assert( 0 == _pb );
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_hMap = CreateFileMapping( INVALID_HANDLE_VALUE, // Map to page file
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&sa, // Security attributes
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PAGE_READWRITE, // Page-level protection
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0, // Size high
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cb, // size low
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pwszName ); // Name
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if ( 0 == _hMap )
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THROW( CException() );
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_pb = (BYTE *) MapViewOfFile( _hMap, // Handle to map
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FILE_MAP_WRITE, // Access
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0, // Offset (high)
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0, // Offset (low)
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0 ); // Map all
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if ( 0 == _pb )
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{
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DWORD dwErr = GetLastError();
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CloseHandle( _hMap );
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_hMap = 0;
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THROW( CException( HRESULT_FROM_WIN32( dwErr ) ) );
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}
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}
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BOOL OpenForRead( WCHAR const * pwszName )
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{
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Win4Assert( 0 == _hMap );
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Win4Assert( 0 == _pb );
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//
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// Note: you have to ask for PAGE_READWRITE even though we only want
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// PAGE_READ, otherwise you get ERROR_ACCESS_DENIED. I don't know
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// why, but since only a limited # of contexts have write access,
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// it should be OK.
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//
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_hMap = OpenFileMapping( PAGE_READWRITE, // Access
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FALSE, // Inherit
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pwszName ); // Name
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if ( 0 == _hMap )
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{
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if ( ERROR_FILE_NOT_FOUND == GetLastError() )
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return FALSE;
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THROW( CException() );
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}
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_pb = (BYTE *) MapViewOfFile( _hMap,
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FILE_MAP_READ, // Access
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0, // Offset (high)
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0, // Offset (low)
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0 ); // Map all
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if ( 0 == _pb )
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{
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DWORD dwErr = GetLastError();
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CloseHandle( _hMap );
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_hMap = 0;
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THROW( CException( HRESULT_FROM_WIN32( dwErr ) ) );
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}
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return TRUE;
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}
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private:
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HANDLE _hMap;
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BYTE * _pb;
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};
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