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

   1 //
   2 // windhoos.cc
   3 //
   4 // mmap() should work now (cygnus beta 18), but let's keep it here
   5 // for people using old cygnus releases
   6 #if 0 // def _WINDOWS32
   7
   8 #include <sys/types.h>
   9 #include <sys/mman.h>
  10 #include <winbase.h>
  11 #include "windhoos-suck-suck-suck-thank-you-cygnus.hh"
  12
  13 /*
  14 HANDLE CreateFileMapping(
  15     HANDLE hFile,       // handle to file to map
  16     LPSECURITY_ATTRIBUTES lpFileMappingAttributes,      // optional security attributes
  17     DWORD flProtect,    // protection for mapping object
  18     DWORD dwMaximumSizeHigh,    // high-order 32 bits of object size
  19     DWORD dwMaximumSizeLow,     // low-order 32 bits of object size
  20     LPCTSTR lpName      // name of file-mapping object
  21 );
  22
  23
  24 LPVOID MapViewOfFile(
  25     HANDLE hFileMappingObject,  // file-mapping object to map into address space
  26     DWORD dwDesiredAccess,      // access mode
  27     DWORD dwFileOffsetHigh,     // high-order 32 bits of file offset
  28     DWORD dwFileOffsetLow,      // low-order 32 bits of file offset
  29     DWORD dwNumberOfBytesToMap  // number of bytes to map
  30 );
  31
  32
  33 io.h:
  34 long _get_osfhandle(int filehandle);
  35 */
  36
  37 // cygnus's gnu-win32-b17.1 does not have _get_osfhandle
  38 // however, after some hacking, it turns out that:
  39
  40 static const int OSF_OFFSET_i = 72;
  41 static const int OSF_BASE_i = -3;
  42 static const int OSF_FACTOR_i = 8;
  43 // let-s hope bill doesn-t change his mind any time soon :-)
  44
  45 // so that, while waiting for cygnus's mmap, we can write:
  46
  47 // #define HAVE_GET_OSFHANDLE  // no we still cannot; works only with cl.exe
  48 long
  49 _get_osfhandle(int filedes_i)
  50 {
  51     return (long)(OSF_OFFSET_i + (filedes_i + OSF_BASE_i) * OSF_FACTOR_i);
  52 }
  53
  54 #ifdef HAVE_GET_OSFHANDLE
  55
  56 #include <iostream.h>
  57
  58 caddr_t
  59 mmap(caddr_t addr, size_t len, int prot, int flags, int fd, off_t offset)
  60 {
  61     (void)flags;
  62     (void)prot;
  63     (void)addr;
  64     HANDLE osf = (HANDLE)_get_osfhandle(fd);
  65     HANDLE file_handle = CreateFileMapping(osf, (void*)0, PAGE_READONLY,
  66         0, len, 0);
  67     return (caddr_t)MapViewOfFile(file_handle, FILE_MAP_READ, 0, offset, len);
  68 }
  69
  70
  71 int
  72 munmap(caddr_t addr, size_t len)
  73 {
  74     (void)len;
  75     return UnmapViewOfFile(addr);
  76 }
  77
  78 #else // ! HAVE_GET_OSFHANDLE //
  79
  80 caddr_t
  81 mmap(caddr_t addr, size_t len, int prot, int flags, int fd, off_t offset)
  82 {
  83     (void)flags;
  84     (void)prot;
  85     (void)addr;
  86     (void)offset;
  87     char* ch_p = new char[ len ];
  88     if (ch_p)
  89         read(fd, (void*)ch_p, len);
  90     return ch_p;
  91 }
  92
  93
  94 int
  95 munmap(caddr_t addr, size_t len)
  96 {
  97     (void)len;
  98     delete (char*)addr;
  99     return 0;
 100 }
 101
 102 #endif // !HAVE_GET_OSFHANDLE //
 103
 104
 105 #endif // _WINDOWS32 //