Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (S)
Guardian Procedure Calls Reference Manual—522629-013
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SEGMENT_ALLOCATE_ Procedure
SEGMENT_ALLOCATE_ Procedure
Summary
Syntax for C Programmers
Syntax for TAL Programmers
Parameters
Considerations
Examples
Related Programming Manual
Summary
The SEGMENT_ALLOCATE_ procedure allocates an extended data segment for use
by the calling process. This procedure can create read/write segments, read-only
segments, and extensible segments.
The SEGMENT_ALLOCATE_ procedure can also be used to share selectable
extended data segments or flat extended data segments allocated by other processes
(subject to the normal security requirements).
For selectable segments, the call to SEGMENT_ALLOCATE_ must be followed by a
call to the SEGMENT_USE_ procedure to make the selectable extended data segment
accessible. Although you can allocate multiple selectable segments, you can access
only one at a time. For flat segments, the call to SEGMENT_ALLOCATE_ can be
followed by a call to SEGMENT_USE_, but calling SEGMENT_USE_ is unnecessary
because all the flat segments allocated by a process are always accessible to the
process.
Flat segments and selectable segments are supported on native processors that use
D30 or later versions of the HP NonStop™ operating system. Selectable segments are
supported on all systems.
Syntax for C Programmers
Note. In the TNS/E environment the CEXTDECS file uses the int data type for 32-bit values.
This is a change from the TNS and TNS/R environments where CEXTDECS uses the long
data type for 32-bit values.