MAPHEADER

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Windows Embedded CE 6.0 R3

4/8/2010

This structures stores header information on a shared memory buffer.

Syntax

typedef struct _MAPHEADER {
    //
    // VERSION 1 DATA
    DWORD  dwBufSize;
    LPBYTE pWrite;
    LPBYTE pRead;
    BOOL   fSetEvent;
    BYTE   bReserved;
    DWORD  dwLostBytes;
    //
    // VERSION 2 DATA
    DWORD  dwVersion;
    DWORD  dwBufferStart;
    DWORD  dwWriteOffset;
    DWORD  dwReadOffset;
} MAPHEADER, *PMAPHEADER;

Members

• dwBufSize
  Size of the data buffer. This does not include the size of the header.

• pWrite
  Pointer to the next location to be written in the buffer.

  Valid for Version 1 of this structure. This pointer will be NULL for version 2 and later.

• pRead
  Pointer to the next location to read from.

  Valid for Version 1 of this structure. This pointer will be NULL for version 2 and later.

• fSetEvent
  Flag indicating whether the fill event can be set.

  The writer sets this value to FALSE; the reader sets this value to TRUE.

• bReserved
  Unused padding for DWORD alignment.

• dwLostBytes
  Total number of lost bytes.

  This value is set by the writer and only read by the reader.

• dwVersion
  Indicates the version of this structure.

• dwBufferStart
  Offset of buffer start from the beginning of the map.

  Valid for Version 2 of this structure.

• dwWriteOffset
  Offset of write pointer from the beginning of the map. The writer moves this pointer.

  Valid for Version 2 of this structure.

• dwReadOffset
  Offset of read pointer from the beginning of the map. The reader moves this pointer, followed by the data buffer. The data buffer starts at dwBufferStart and ends dwBufSize bytes beyond that.

  Valid for Version 2 of this structure.

Remarks

This structure specifies different members for different versions of Windows Mobile. Version 1 data applies to all versions of Windows Mobile.

Requirements

See Also

Other Resources