Preventing infinite program loops
Processor protection deters infinite program loops that could affect availability. Inserting a timer prevents programs from being stuck in infinite loops, and never returning control to the operating system. The operating system timer can be fixed or variable. However, the system parameter for the timer should be set at a generally accepted practice range with instructions to interrupt the operating system timer considered a privileged authorization for incident prevention.
Reducing the risk of IT program manipulation
Lastly, user program protection dictates user access to shared user resources. Rather than include all necessary instructions in an application program, many programs simply reference other programs, or subroutines, that may be available in the program library. When a program makes a reference to subroutine, it is the operating system that calls the subroutine in from the library and makes it available to the requesting program.
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“View Part I of the Essential Operating System Protection Mechanisms series here”
Post Note: “Essential Operating System Protection Mechanisms – Part IV” was originally published through Suite101.com under the title “Essential Operating System Protection Mechanisms”