InitializeFastIo

Available since: Windows Packet Filter 3.2.20

The InitializeFastIo function maps a shared memory section (FAST_IO_SECTION) between the user-mode application and ndisrd.sys for packet transfer using a shared section header and an array of packet buffers.

Syntax

BOOL WINAPI InitializeFastIo(
    _In_ HANDLE           hOpen,
    _In_ PFAST_IO_SECTION pFastIo,
    _In_ DWORD            dwSize
);

Remarks

Fast I/O makes captured packets available in user-allocated shared memory. The application reads the packet array using the section header and synchronization flags; see the official fastio_packet_filter.h example. dwSize must be at least sizeof(FAST_IO_SECTION), and Windows Vista or later is required. Because Fast I/O relies on direct memory mapping, WOW64 mode is not supported. The unsorted packet APIs also reject WOW64. Applications running under WOW64 should use the ordinary per-adapter ReadPacket/ReadPackets and SendPacket(s) APIs, which perform the required structure and handle conversions.