Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (C)
Guardian Procedure Calls Reference Manual—522629-013
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CHECKALLOCATESEGMENT Procedure
(Superseded by SEGMENT_ALLOCATE_CHKPT_
between processors. An error is returned from ALLOCATESEGMENT on the
backup.
•
Nonexisting temporary swap file
If a shared segment is being allocated (
pin-and-flags bits <3:2> not equal to
0), and a volume name only is supplied in the
file-name parameter, then the
complete file name of the temporary file created by CHECKALLOCATESEGMENT
is returned.
•
Swap file extent allocation
If an extensible segment is being created, then only one extent of the swap file is
allocated when CHECKALLOCATESEGMENT returns.
•
Segment sharing
Subject to security requirements, a process can share a segment with another
process running on the same processor. For example, process $X can share a
segment with any of the following processes on the same processor:
•
Any process that has the same process access ID (PAID)
•
Any process that has the same group ID, if $X is the group manager (n,255)
•
Any process, if $X is the super ID (255,255)
If processes are running in different processors, they can share a segment only if
the security requirements are met and the segment is a read-only segment.
Callers of [CHECK]ALLOCATESEGMENT can share segments with callers of
SEGMENT_ALLOCATE_[CHKPT_ ]. High-PIN callers can share segments with
low-PIN callers.
•
Sharing flat segments
A process cannot share a flat segment with a process that allocated a selectable
segment, because the segments reside in different parts of memory. (Similarly, a
process cannot share a selectable segment with a process that allocated a flat
segment.)