src/windhoos-suck-suck-suck-thank-you-cygnus.cc

   1 //
   2 // windhoos.cc
   3 //
   4 #ifdef _WIN32
   5
   6 #include <sys/types.h>
   7 #include <sys/mman.h>
   8 #include <winbase.h>
   9
  10 /*
  11 HANDLE CreateFileMapping(
  12     HANDLE hFile,       // handle to file to map
  13     LPSECURITY_ATTRIBUTES lpFileMappingAttributes,      // optional security attributes
  14     DWORD flProtect,    // protection for mapping object
  15     DWORD dwMaximumSizeHigh,    // high-order 32 bits of object size
  16     DWORD dwMaximumSizeLow,     // low-order 32 bits of object size
  17     LPCTSTR lpName      // name of file-mapping object
  18    );
  19
  20
  21 LPVOID MapViewOfFile(
  22     HANDLE hFileMappingObject,  // file-mapping object to map into address space
  23     DWORD dwDesiredAccess,      // access mode
  24     DWORD dwFileOffsetHigh,     // high-order 32 bits of file offset
  25     DWORD dwFileOffsetLow,      // low-order 32 bits of file offset
  26     DWORD dwNumberOfBytesToMap  // number of bytes to map
  27    );
  28
  29
  30 io.h:
  31 long _get_osfhandle( int filehandle );
  32 */
  33
  34 // cygnus's gnu-win32-b17.1 does not have _get_osfhandle
  35 // however, after some hacking, it turns out that:
  36
  37 static const int OSF_OFFSET_i = 72;
  38 static const int OSF_BASE_i = -3;
  39 static const int OSF_FACTOR_i = 8;
  40 // let-s hope bill doesn-t change his mind any time soon :-)
  41
  42 // so that, while waiting for cygnus's mmap, we can write:
  43
  44 // #define HAVE_GET_OSFHANDLE  // no we still cannot; works only with cl.exe
  45 long
  46 _get_osfhandle( int filedes_i )
  47 {
  48     return (long)( OSF_OFFSET_i + ( filedes_i + OSF_BASE_i ) * OSF_FACTOR_i );
  49 }
  50
  51 #ifdef HAVE_GET_OSFHANDLE
  52
  53 #include <iostream.h>
  54
  55 caddr_t
  56 mmap(caddr_t addr, size_t len, int prot, int flags, int fd, off_t offset)
  57 {
  58     (void)flags;
  59     (void)prot;
  60     (void)addr;
  61     HANDLE osf = (HANDLE)_get_osfhandle( fd );
  62     HANDLE file_handle = CreateFileMapping( osf, (void*)0, PAGE_READONLY,
  63         0, len, 0 );
  64     return (caddr_t)MapViewOfFile( file_handle, FILE_MAP_READ, 0, offset, len );
  65 }
  66
  67
  68 int
  69 munmap(caddr_t addr, size_t len)
  70 {
  71     (void)len;
  72     return UnmapViewOfFile( addr );
  73 }
  74
  75 #else // ! HAVE_GET_OSFHANDLE //
  76
  77 caddr_t
  78 mmap(caddr_t addr, size_t len, int prot, int flags, int fd, off_t offset)
  79 {
  80     (void)flags;
  81     (void)prot;
  82     (void)addr;
  83     (void)offset;
  84     char* ch_p = new char[ len ];
  85     if ( ch_p )
  86         read( fd, (void*)ch_p, len );
  87     return ch_p;
  88 }
  89
  90
  91 int
  92 munmap(caddr_t addr, size_t len)
  93 {
  94     (void)len;
  95     delete (char*)addr;
  96     return 0;
  97 }
  98
  99 #endif // !HAVE_GET_OSFHANDLE //
 100
 101
 102 #endif // _WIN32 //