_FAST_IO_SECTION_HEADER

struct _FAST_IO_SECTION_HEADER{
    FAST_IO_WRITE_UNION fast_io_write_union;
    ULONG read_in_progress_flag;
};

This structure serves as a shared section header for fast I/O

fast_io_write_union
Contains information regarding write operations into the shared memory.

read_in_progress_flag
Indicates is shared section is busy with read operation.

Available starting version 3.2.20. Fast I/O is supported for Windows Vista and later. WOW64 mode is not supported.