The system call interface is a mechanism used by computer programs to interact with the operating system. It provides a set of functions or services that can be used to perform various operations, such as reading and writing files, managing processes, and controlling input/output devices. In some cases, the same system call interface may be used for both file and device manipulation. Its called Shared Systems Calls. While this approach has its advantages, it also has some disadvantages that should be considered.

Advantages of Shared System Calls:

  1. Simplified Code: Using the same system call interface for both files and devices can simplify the code needed to access these resources. This is because the same set of functions can be used for both tasks, which can make it easier for developers to write and maintain code.
  2. Consistent Interface: Having a consistent interface for file and device manipulation can make it easier for users to understand how to interact with different resources. This can reduce confusion and make it easier to use different programs and devices.
  3. Resource Sharing: Using the same system call interface for both files and devices can make it easier to share resources between different applications. For example, a device driver can use the same file system interface to access both files and devices, which can make it easier to share resources and avoid conflicts.

Disadvantages of Shared System Calls:

  1. Limited Functionality: Using the same system call interface for both files and devices can limit the functionality available for each type of resource. For example, some operations that are specific to devices, such as controlling hardware settings or accessing device-specific information, may not be available when using a file system interface.
  2. Performance Overhead: Using a general system call interface for both files and devices can introduce performance overhead, as the system call may have to perform additional checks to determine the type of resource being accessed. This can result in slower performance and increased resource usage.
  3. Complexity: Using the same system call interface for both files and devices can increase the complexity of the interface, as it must be designed to handle both types of resources. This can make the interface more difficult to understand and use, which can be a problem for novice users.

OS-2022

Q-1.

(a) Write are the functions of operating systems? write a note on multi programmed operating systems ?

(b) Distinguish between client server and peer to peer model of distributed systems .

Q-2.

(a) With a Neat Sketch, Describe the services that an Operating System provides to users, processes and other systems.

(b) What is meant by Storage Structure? Discuss Storage Hierarchy.

(c) Write the Advantages and Disadvantages of using the same system call interface for manipulating both Files and Devices.

Q-3.

(a) What are the criteria for evaluating the CPU scheduling algorithms? Why do we need it?

(b) Define process. Explain various steps involved in change of a process state with process state neat transition diagram.

Q-4.

(a) What is synchronization? Explain how semaphores can be used to deal with n-process critical problem.

(b) Define a thread. Give the benefits of multithreading. What resources are used when a thread is created?

Q-5.

(a) How dose deadlock avoidance differ from deadlock prevention? Write about deadlock avoidance algorithm in detail.

(b) Different between external fragmentation and internal fragmentation. How to solve the fragmentation using paging?

Q-6.

(a) What is the purpose of paging the page table? Consider the following page reference string 1,2,3,4,5,1,2,3,4,5 for a memory with three frames. How many page faults would LRU and FIFO replacement algorithm?

(b) What are the disadvantages of single contiguous memory allocation? Explain.

Q-7.

(a) Briefly explain about single-level, two-level and three Structured directories.

(b) What is disk scheduling? Explain the C-SCAN scheduling by giving an example.

Q-8.

(a) Interrupt and spooling.

(b) UNIX file system.

(c) Program and system threats.