OS 2021 A1 Batch Quiz 2

A system call that never returns on success is _________

• Fork()
• Execl()
• Getpid()
• Vfork()

A process executes the code. How many processes are newly created main(){ fork (); fork (); fork ();}

• 7
• 4
• 8
• 3

A thread is usually defined as a ‘light weight process’ because an operating system (OS) maintains smaller data structures for a thread than for a process. In relation to this, which of the followings is TRUE?

• The OS does not maintain a separate stack for each thread
• On per thread basis, the OS maintains only scheduling and accounting information.
• On per-thread basis, the OS maintains CPU register state and stack
• On per-thread basis, the OS does not maintain virtual memory state

Which header file is required to invoke wait system call

• <sys/types.h>

• <unistd.h>

• <stdlib.h>

• <sys/wait.h>

Kernel mode is also known as

• Privileged mode
• System mode
• Supervisor mode
• All of the above

Microkernels use _____ for communication.

• message passing
• shared memory
• system calls
• virtualization

Which of the following is FASLE

• Vfork uses copy-on-write to save resources
• Dual Mode Operation is to ensure protection and security of the System
• Real-time systems use priority based scheduling
• A hard real-time system meets response requirements under all conditions

Which of the multithreading model, the entire process does not blocks when a thread makes blocking system call

• Many to one
• Many-to-many
• One to many
• None of the above

Following fork() system call, parent or the child process calls_______, which replaces the process code with new program code.

• execle
• wait
• exit
• vfork

A child process created using fork system call shares with parent process which of the following

• Heap
• Stack
• Shared memory
• None of the above