Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (S)
Guardian Procedure Calls Reference Manual—522629-013
14-27
SEGMENT_DEALLOCATE_CHKPT_ Procedure
flags input
INT:value
specifies whether dirty pages must be written to the swap file. A dirty page is a
page in memory that has been updated but not written to the swap file. Valid
values are:
<0:14> Reserved (specify 0)
<15> 1 Indicates that dirty pages in memory are not to be written to the swap
file.
0 Indicates that dirty pages in memory are to be written to the swap file.
The default is 0.
error-detail output
INT .EXT:ref:1
returns additional information associated with some errors. See
error for details.
If
error is 4, error-detail returns one of the following values:
1
segment-id is out of range.
2
segment-id is in range but not allocated by the caller.
3 Segment is currently in use by the system. It might be in this state
because an outstanding nowait I/O operation using a buffer within the
segment has not been completed by a call to AWAITIOX.
30 No message-system control blocks are available.
31 There is no room in the process file segment (PFS) for a message buffer in
either the backup or the primary.
201 Unable to send to the backup.
Considerations
•
The segment need not be allocated by the primary process at the time of the call to
SEGMENT_DEALLOCATE_CHKPT_.
•
flags parameter
If the swap file associated with an extended data segment is not a temporary file,
all of the modified pages of the segment are written to the file before it is closed by
the last process using it. This is also true for a swap file that was created as a
temporary file but was later renamed. (A program might use this method to keep
its temporary file.) However, if the extended segment is large and if there are a
large number of modified (“dirty”) pages, it might take a long time to deallocate the
file. If
flags.<15> is set to 1, the modified pages are not written to the swap file,
even if it is a permanent file. This option is recommended when the swap file has