Arguments

 

efn

   OpenVMS usage:ef_number
   type:         longword (unsigned)
   access:       read only
   mechanism:    by value
   Number of any event flag within the event flag cluster to be
   used. The efn argument is a longword containing this number;
   however, $WFLAND uses only the low-order byte. Specifying the
   number of an event flag within the cluster serves to identify the
   event flag cluster.

   There are two local event flag clusters: 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.
 

mask

   OpenVMS usage:mask_longword
   type:         longword (unsigned)
   access:       read only
   mechanism:    by value
   Event flags for which the process is to wait. The mask argument
   is a longword bit vector wherein a bit, when set, selects the
   corresponding event flag for which to wait.