iX V6.5 (30391-90011)

206 Chapter5

TurboIMAGE/XL Library Procedures

DBLOCK

2 The number of lock descriptors that were successfully

applied in the DBLOCK request. For successful locks in

modes 1 through 4 this will be 1.

3 If the return status is 20, this element contains 0 if the

database is locked, 1 if the data set or entries are locked.

4 Reserved: Contents undeﬁned.

5-10 Information about the procedure call and its results. Refer

to "Library Procedure Error Messages" in appendix A for a

complete description of this information.

NOTE

Concurrent processes running in a process-handling environment must have

MR capability if they call DBLOCK.

Discussion

The format of the array containing a list of lock descriptors is illustrated in Figure 5-2. and

applies only for locking modes 5 or 6. The number of lock descriptors (n) is a one-halfword

binary integer. Only the ﬁrst n lock descriptors are processed. If n is zero, DBLOCK returns

without taking any action. The format of a lock descriptor is illustrated in Figure 5-3., and

the lock descriptor ﬁelds are described in Table 5-16.

The shortest possible descriptor is 9 halfwords long consisting of the length ﬁeld and a dset

ﬁeld containing @. Although the dset ﬁeld only contains an at-sign, it must still be 8

halfwords long. The length of the entire descriptor array cannot exceed 4094 bytes.

Lock descriptors are sorted by data set number, then by value provided for the lock item.

TurboIMAGE/XL does not sort by item within the set, because more than one item per

data set constitutes a conﬂicting lock descriptor (TurboIMAGE/XL error −134).