BPXYBRLK — Map byte range lock request for fcntl

                                                      
            BPXYBRLK   ,                                                        
** BPXYBRLK: External Byte Range Locking interface control block                
**  Used By: FCT                                                                
BRLK                 DSECT ,                                                    
L_TYPE               DS    H      Requested lock type:                          
F_RDLCK              EQU   1       Shared or read lock                          
F_WRLCK              EQU   2       Exclusive or write lock                      
F_UNLCK              EQU   3       Unlock                                       
L_WHENCE             DS    H      Flag for starting offset                      
L_START              DS    0CL8   Relative offset in bytes                      
L_START_H            DS    F      High word of relative offset                  
L_START_L            DS    F      Low word of relative offset                   
L_LEN                DS    0CL8   Size of lock in bytes                         
L_LEN_H              DS    F      High word of size of lock in bytes            
L_LEN_L              DS    F      Low word of size of lock in bytes             
L_PID                DS    F      Process ID of process holding lock            
BRLK#LENGTH          EQU   *-BRLK Length of this area                           
** BPXYBRLK End