$IO_PERFORMW_(Alpha_and_Integrity_servers)

   On Alpha and Integrity server systems, starts a Fast I/O
   operation. The $IO_PERFORMW service completes synchronously;
   that is, it returns to the caller after performing the Fast I/O
   operation.

   In all other respects, $IO_PERFORMW is identical to $IO_PERFORM.
   For all other information about the IO_PERFORMW service, see the
   help for $IO_PERFORM.

   Format

     SYS$IO_PERFORMW  fandle ,chan ,iosadr ,bufadr ,buflen ,devdata

   C Prototype

     int sys$io_performw  (unsigned __int64 fandl, unsigned short

                          int chan, struct _iosa *iosadr, void

                          *bufadr, unsigned __int64 buflen, unsigned

                          __int64 devdata);