Arguments

 

efn

   OpenVMS usage:ef_number
   type:         longword (unsigned)
   access:       read only
   mechanism:    by value
   Number of any event flag in the cluster whose status is to be
   returned. The efn argument is a longword containing this number;
   however, $READEF uses only the low-order byte. Specifying an
   event flag within a cluster requests that $READEF return the
   status of all event flags in that cluster.

   There are two local event flag clusters, which are local to the
   process: cluster 0 and cluster 1. Cluster 0 contains event flag
   numbers 0 to 31, and cluster 1 contains event flag numbers 32 to
   63.

   There are two common event flag clusters: cluster 2 and cluster
   3. Cluster 2 contains event flag numbers 64 to 95, and cluster 3
   contains event flag numbers 96 to 127.
 

state

   OpenVMS usage:mask_longword
   type:         longword (unsigned)
   access:       write only
   mechanism:    by 32- or 64-bit reference (Alpha and Integrity
                 servers)
   State of all event flags in the specified cluster. The state
   argument is the 32- or 64-bit address (on Alpha and Integrity
   server systems) of a longword into which $READEF writes the state
   (set or clear) of the 32 event flags in the cluster.