Arguments

 

efn

   OpenVMS usage:ef_number
   type:         longword (unsigned)
   access:       read only
   mechanism:    by value
   Number of the event flag specified in the call to the system
   service whose completion status is to be checked by $SYNCH.
   The efn argument is a longword containing this number; however,
   $SYNCH uses only the low-order byte.
 

iosb

   OpenVMS usage:io_status_block
   type:         quadword (unsigned)
   access:       read only
   mechanism:    by 32- or 64-bit reference (Alpha and Integrity
                 servers)
   I/O status block specified in the call to the system service
   whose completion status is to be checked by $SYNCH. The iosb
   argument is the address of this quadword I/O status block.