IDMS programs: system-mode or user-mode

Products

• IDMS

Issue/Introduction

All programs running in an IDMS address space run in system-mode or user-mode. This is an important distinction for the understanding of storage protection. This article documents which programs are system-mode and which are user-mode.

Environment

Release: All supported releases.

Resolution

Display the program definition at the ENTER NEXT TASK CODE: prompt.  If it says Type NUCLEUS, it is system-mode, anything else is user-mode.

Examples:

DCMT D PRO *.IDMSDBMS
  Program Name IDMSDBMS            Ddname          CDMSLIB
  Type         NUCLEUS             Type            LOADLIB
  Language     ASM                 Dictname

DCMT D PRO *.ADSOMAIN                                     
  Program Name ADSOMAIN            Ddname          CDMSLIB
  Type         PROGRAM             Type            LOADLIB

IDMSDBMS is a system-mode program. ADSOMAIN is a user-mode program.

User-written programs generally run in user-mode except for some particular types of program which can be invoked by an IDMS system-mode program. Whether or not such user-written programs run in system-mode is typically specified where the entity that invokes that program is defined.

Examples of these programs are:
SQL-invoked routines such as table procedures, procedures and functions.
User exits.

Database procedures always run in system-mode.