Assume That An Operating System Is Written For A Machine

Assume That An Operating System Is Written For a Machine Architectu

Assume that an operating system is written for a machine architecture that has the following attributes: (a) a single processor, with some fixed number M of CPU registers (b) base-limit register addressing (c) a fixed set of N peripheral devices at known bus addresses. The process scheduler uses information about how much processor time a process has had and how long it has been in existence to decide which process to run next. The operating system keeps track of which processes have created which other processes. Processes can signal each other as a means of synchronizing their respective behaviors. Signals are small integer values. Processes can share their executable code.

Design a pseudo-code structure for a Process Control Block (PCB) suitable for managing processes in such an operating system. Identify the necessary members of the PCB, their data types, and their roles in process management and synchronization.

Paper For Above instruction

The Process Control Block (PCB) is a fundamental data structure used by operating systems to maintain information about each process in the system. For the architecture described—a single processor with fixed register count, base-limit addressing, and a predefined set of peripheral devices—the PCB must include members that facilitate process scheduling, memory management, process creation and hierarchy tracking, inter-process communication, and synchronization.

Key Members of the PCB and Their Data Types

  • Process ID (PID): int
  • Process State: enum or int (e.g., NEW, READY, RUNNING, WAITING, TERMINATED)
  • Program Counter (PC): unsigned int or size_t
  • Register Set: array of M registers (e.g., int registers[M]) — stores the current CPU register states for context switching
  • Base Register Address: unsigned int
  • Limit Register Address: unsigned int
  • Process Creation Hierarchy: int parentPID, list of childPIDs
  • Execution Time and Age: double timeExecuted, age — used by the scheduler to decide process priority
  • Signals: list or array of int — small integers representing signals received for synchronization
  • Shared Code Pointer: void * or function pointer — points to the executable code shared among processes
  • I/O Device State: structure containing device-specific info — to manage peripheral devices with known bus addresses

This collection of members allows the operating system to effectively manage process execution, context switching, process creation, inter-process signaling, and sharing executable code under the described hardware architecture. Addressing constraints such as base-limit register addressing are accommodated through the stored base and limit addresses, enabling safe memory access for each process. The timing information supports scheduling policies that consider both CPU usage and process age, promoting fairness and efficiency in process execution.

References

  • Silberschatz, A., Galvin, P. B., & Gagne, G. (2018). Operating System Concepts (10th ed.). Wiley.
  • Tanenbaum, A. S., & Bos, H. (2014). Modern Operating Systems (4th ed.). Pearson.
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  • Arpaci-Dusseau, R. H., & Arpaci-Dusseau, A. C. (2018). Operating Systems: Three Easy Pieces. Arpaci-Dusseau Books.
  • Schimmel, R. (2012). Processes, Threads, and Concurrency. University of California.
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  • Silberschatz, A., & Galvin, P. B. (2002). Operating System Principles. Wiley.
  • Lea, D. (2013). Concurrent Programming in Java: Design Principles and Pattern. Addison-Wesley.
  • Gent, S., & Van de Van, S. (2017). Fundamentals of Operating Systems. Cambridge University Press.

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