1 /*  START OF:       dm_lock_modes.incl.pl1                    *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  */
 2 
 3 /* DESCRIPTION:
 4 
 5      Hierarchical lock modes for Data Management control interval locking.  In
 6 addition to conventional read and write locks, intention locks are provided
 7 for finer locking granularity.
 8 */
 9 
10 /* HISTORY:
11 Written by Jeffrey D. Ives, 04/30/82.
12 Modified:
13 12/05/84 by Stanford S. Cox: Added Description.
14 */
15 /* format: style3,idind25 */
16 
17      dcl     LOCK_MODE_S            fixed bin static options (constant) init (2);
18      dcl     LOCK_MODE_X            fixed bin static options (constant) init (3);
19      dcl     LOCK_MODE_IS           fixed bin static options (constant) init (4);
20      dcl     LOCK_MODE_IX           fixed bin static options (constant) init (5);
21      dcl     LOCK_MODE_SIX          fixed bin static options (constant) init (6);
22 
23      dcl     LOCK_ENTIRE_FILE       fixed bin (27) static options (constant) init (-1);
24 
25      dcl     LOCK_MODE_NAMES (2:6)  char (3) int static options (constant)
26                                     init ("  S", "  X", " IS", " IX", "SIX");
27 
28 /*
29      S       Share                           Let others read it but not modify it.
30      X       Exclusive                       Let nobody else read or modify it.
31      IS      Intention Share                 I am only using S locks, because I am only reading CIs.
32      IX      Intention Exclusive             I am using S and X locks, because I am reading and modifying CIs.
33      SIX     Share with Intention Exclusive  I am reading control intervals, but only locking the ones I modify.
34 */
35 
36 /*  END OF:         dm_lock_modes.incl.pl1                    *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  *  */