Questions and Answers
What is a process?
An executing program that can launch other processes and be launched by other processes.
What are the main components of a process?
Code, data, stack, heap, and the process control block.
Which of the following are process states? (Select all that apply)
The kernel operates in low memory.
Signup and view all the answers
What is a job queue?
Signup and view all the answers
What is a ready queue?
Signup and view all the answers
What are device queues?
Signup and view all the answers
What is the function of a long-term scheduler?
Signup and view all the answers
Describe an I/O bound process.
Signup and view all the answers
Describe a CPU bound process.
Signup and view all the answers
What is the role of the short-term scheduler?
Signup and view all the answers
What is a context switch?
Signup and view all the answers
How is a process created?
Signup and view all the answers
What are the ways a process can terminate?
Signup and view all the answers
What does the fork
system call do?
Signup and view all the answers
What does the execv
function do?
Signup and view all the answers
What is the purpose of the exit
system call?
Signup and view all the answers
What does the wait
system call do?
Signup and view all the answers
What is the key difference between independent and cooperating processes?
Signup and view all the answers
Why do we use cooperating processes?
Signup and view all the answers
What is Inter-Process Communication (IPC)?
Signup and view all the answers
How do message-passing systems work?
Signup and view all the answers
What operations does IPC provide?
Signup and view all the answers
Study Notes
Process Overview
- A process is an executing program, distinct and capable of launching or being launched by other processes.
- Key components within a process include code, data, stack, heap, and a Process Control Block (PCB) containing process state, priority, accounting information, program counter, registers, and open files.
Process States
- New: The process is being created.
- Running: Instructions are currently being executed.
- Waiting (Blocked): The process awaits an event.
- Ready: The process is poised for CPU assignment.
- Terminated: The process has completed execution.
Memory Allocation
- Kernel memory operates at high levels, while user memory functions at lower levels.
Queues in Process Management
- Job Queue: Contains all processes in the system.
- Ready Queue: Includes processes in memory, ready for execution.
- Device Queues: Holds processes waiting for I/O devices.
Scheduling
- Long-term Scheduler (Job Scheduler): Decides which processes enter the ready queue, invoked infrequently; controls multiprogramming balance.
- I/O Bound Process: Prioritizes I/O operations over computations, exhibiting many short CPU bursts.
- CPU Bound Process: Focuses on computations, characterized by few long CPU bursts.
- Short-term Scheduler (CPU Scheduler): Determines the next process for execution and allocates CPU resources frequently.
Context and Process Management
- Context Switch: Involves switching from one process to another, managed by the scheduler (dispatcher).
-
Process Creation: Initiated through system calls like
fork()
, user commands, or batch jobs. - Process Termination: Can occur normally via main exit, with errors, or through external termination commands.
System Calls for Process Management
- fork(): Creates a new process that is an exact copy of the calling process, with distinct memory images post-call; the parent receives the child's process ID while the child receives 0.
-
execv(): Replaces the calling process's memory with a new program specified by
programName
, using the argument vectorargv
. - exit(): Causes a process to terminate, returning a code to the parent if the parent waits for the child’s termination.
- wait(): Makes a calling process pause until its created processes exit, retrieving the exit code.
Process Types
- Independent Process: Operates without influencing or being influenced by other processes.
- Cooperating Process: Interacts with other processes, potentially affecting their execution.
Advantages of Cooperating Processes
- Facilitate information sharing, enhance computational efficiency, promote modular design, and increase convenience.
Inter-Process Communication (IPC)
- IPC mechanisms enable processes to communicate and synchronize actions, including:
- Shared Memory Systems: Allow processes to share a designated memory region.
- Message-Passing Systems: Enable processes to exchange messages for collaboration without shared variables.
Message Passing
- In message-passing systems, processes communicate distinctly through message exchanges instead of shared data variables.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on key concepts of processes in systems programming with this comprehensive flashcard quiz. Explore definitions, states, and components related to processes in computing. Perfect for reviewing systems study materials and preparing for exams.