MPE/iX Intrinsics Reference Manual (32650-90905)

Chapter 2 29
Intrinsic Use
Additional Capabilities Required
Additional Capabilities Required
Most system intrinsics do not require additional capabilities to access operating system
features. However, if an intrinsic requires the operating system to check for an additional
capability at program load and/or run time, that capability must be assigned prior to
running the program.
Table 2-6. lists additional capabilities and the assignments required by some intrinsics.
NOTE A system manager or account manager must assign the capabilities to the
group where the program file resides or to the user running the program. You
must assign PH, DS, MR, and PM capabilities to the program file at link time
using the caplist parameter of the LINK command.
The operating system performs two capability checks prior to executing the program. The
checks must succeed before the program can run:
• At load time, the file system checks the user capability list against the account-level,
group-level, and file-level security provisions for the program file and all referenced
executable library (XL) files.
• At load time, the loader checks the program file's capability list against the capability
list for the group in which the program file resides. If the program is located in a
temporary file, the loader checks the program file's capability list against the capability
list for the user who is running the program. In this case, the capability must be
assigned to the user in addition to (or instead of) the group.
A third capability check occurs at run time when the program executes the code of an
intrinsic that requires a capability. The intrinsic checks either the program file (for DS,
MR, ND, PH, or PM) or the user (for LG, OP, or PS). If the operating system does not find
the correct capability, the program aborts.
Table 2-6. Additional Capabilities Required
Capability Required Assignment To
Data segment management (DS) The program file and the group in which that file resides
User logging (LG) The user running the program
Multiple RIN (MR) The program file and the group in which that file resides
Nonshareable device (ND) The user running the program
System supervisor (OP) The user running the program
Process handling (PH) The program file and the group in which that file resides
Privileged mode (PM) The program file and the group in which that file resides
Programmatic sessions (PS) The user running the program