Hardware and Operating System SAP R/3 Basis ... - SAP Techies

Introduction To SAP R/3 Basis
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The task handler coordinates activity within a dialog work process. It activates
the screen processor or the ABAP processor (which control the screen flow
logic and process ABAP statements, respectively) and executes the roll-in and
the roll-out of the user context.
The memory management system differentiates between main memory areas
that are available exclusively to a work process, and memory areas that can be
used by all work processes. The memory space used exclusively by a work
process stores session-specific data that must be kept longer than the duration
of a work step. This data is automatically made available to the process at the
start of a dialog step (rolled-in) and saved at the end of the dialog step (rolledout).
This data characterizes users (user context), such as their authorizations,
administration information and additional data for the ABAP and dialog
processor. Also it contains data collected by the system in the preceding dialog
steps in the running transaction (see following slide). Additional memory areas
used by all processes in shared memory include areas for the factory calendar,
screen, table, and program buffers.
Understanding a User Context
A user context is memory that is allocated to contain the characteristics of a
user that is logged on the R/3 system. It holds information needed by R/3
about the user, such as:
The user's current settings
The user's authorizations
The names of the programs the user is currently running
When a user logs on, a user context is allocated for that logon. When they
log off, it is freed. It is used during program processing, and its importance
is described further in the following sections.
Understanding a Roll Area
A roll area is memory that is allocated by a work process for an instance of
a program. It holds information needed by R/3 about the program's
execution, such as:
The values of the variables
The dynamic memory allocations
The current program pointer
Compiled By: Ashwin Vavaiya 16 of 44