Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (S)
Guardian Procedure Calls Reference Manual—522629-013
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SEGMENT_USE_ Procedure
SEGMENT_USE_ Procedure
Summary
Syntax for C Programmers
Syntax for TAL Programmers
Parameters
Considerations
Example
Related Programming Manual
Summary
The SEGMENT_USE_ procedure selects a particular extended data segment to be
currently addressable by the calling process.
For selectable segments, the call to SEGMENT_USE_ must follow a call to
SEGMENT_ALLOCATE_ to make the selectable extended data segment accessible.
Although you can allocate multiple selectable extended data segments, you can
access only one at a time.
For flat segments, the call to SEGMENT_USE_ can follow a call to
SEGMENT_ALLOCATE_, but calling SEGMENT_USE_ is unnecessary because all of
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 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.