TurboIMAGE/XL Database Management System Reference Manual MPE/iX V6.5 (30391-90011)

Appendix B 639
Results of Multiple Access
B Results of Multiple Access
When opening a database with DBOPEN, TurboIMAGE/XL returns information in the
status array describing the results of the procedure call. Figure B-1., “Actions Resulting
from Multiple Access of Databases.” can be used to interpret these results when multiple
processes are using the database.
Each box in Figure B-1. is associated with a requested mode or TurboIMAGE/XL utility
routine identified at the far left of the row in which the box appears. It is also associated
with a possible current access mode or utility routine identified at the top of the column in
which the box appears. The contents of the boxes can be used to determine the results of a
DBOPEN call.
If access is granted, condition code CCE is returned and the first element of the status
array contains a zero. The boxes containing G represent this situation.
If access is not granted, and the reason relates to current database activity, the results are
like those shown in the other boxes. Two types of situations can occur:
• If the first two elements of the status array contain −1 and 0, respectively, the third
element of status will contain a single number. This number is the MPE/iX failure code
returned from the FCHECK intrinsic. See the MPE/iX Intrinsic Reference Manual for
MPE/iX failure code meanings. If that number is 48, 90, or 91, the failure occurred
because current access to the database does not permit it to be opened in the requested
mode. Find the boxes in the requested mode row which contain a number equal to the
third status element. The possible modes and utility routines which other processes
could be using are the ones which label the columns containing these boxes. For
example, if the third status element contains 48 and the requested mode is 2, the
possible current modes are 1 and 5.
To find an alternate mode for accomplishing the task, look down the columns containing
these boxes for one containing a G. If the requested mode labeling the row in which the
G resides can be used, try opening the database with that mode. In the example above,
alternate modes would be 1 or 5 because these rows contain G in columns 1 and 5.
If the box with contents matching the third status element is in a column associated
with a utility, usually the only choice is to wait until execution terminates. When
DBSTORE is being run, it is possible to open the database with mode 6 or 8.
• If the first element in the status array contains −32, the failure occurred because the
root file could be opened but not with the necessary AOPTIONS. This value can also be
returned in situations not related to multiple access. See appendix A in this manual
and the description of the AOPTIONS parameter of the FOPEN intrinsic in the MPE/iX
Intrinsics Reference Manual. Use the same technique described above to determine the
possible current modes or other activity and to select a course of action. For example, if
the requested mode is 2 and the first element of status equals −32, possible current
modes are 4 and 8, and the DBSTORE utility could be executing.
The messages enclosed in quotes are printed when the situation represented by the row