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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 dwBufferStartand ends dwBufSizebytes 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

Header celog.h
Windows Embedded CE Windows CE .NET 4.0 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also

Other Resources