Step 1: Define multiprogramming and uni-processor.
- A uni-processor system has only one central processing unit (CPU).
- Multiprogramming is a technique that allows the CPU to execute multiple programs concurrently. It aims to keep the CPU busy as much as possible by having it work on another program when the current one is waiting for an I/O operation.
Step 2: Analyze how multiprogramming works on a uni-processor system.
Since there is only one CPU, it can only execute one instruction at a time. To run multiple programs concurrently, the operating system uses scheduling to rapidly switch the CPU's execution between different programs (processes). This is known as time-sharing or context switching. It creates the illusion that multiple programs are running simultaneously.
Step 3: Evaluate the options.
(A) This describes multiprocessing, not multiprogramming on a uni-processor system.
(B) This accurately describes how multiprogramming is achieved on a single CPU: dividing the CPU's time among different programs.
(C) This is false. Multiprogramming is a core concept designed for uni-processor systems.
(D) This is a contradiction in terms. A uni-processor system has only one processor.
Consider a system with the following: - \(\mathbb{P} = \{ P_1, P_2, P_3, P_4 \}\) consists of all active processes in an operating system. - \(\mathbb{R} = \{ R_1, R_2, R_3, R_4 \}\) consists of single instances of distinct types of resources in the system.
The resource allocation graph has the following assignment and claim edges: Assignment edges: \[ R_1 \to P_1, \quad R_2 \to P_2, \quad R_3 \to P_3, \quad R_4 \to P_4 \] (The assignment edge \( R_1 \to P_1 \) means resource \( R_1 \) is assigned to process \( P_1 \), and so on for others.)
Claim edges: \[ P_1 \to R_2, \quad P_2 \to R_3, \quad P_3 \to R_1, \quad P_2 \to R_4, \quad P_4 \to R_2 \] (The claim edge \( P_1 \to R_2 \) means process \( P_1 \) is waiting for resource \( R_2 \), and so on for others.)
Which of the following statement(s) is/are CORRECT?