D686 - Operating Systems - Chapter 4

single-threaded

A process or program that has only one thread of control (and so executes on only one core at a time).

multithreaded

A term describing a process or program with multiple threads of control, allowing multiple simultaneous execution points.

user thread

A thread running in user mode.

kernel threads

Threads running in kernel mode.

thread control block (TCB)

a data structure in an operating system that stores information about a thread, including its identifier, state, CPU information, priority, and pointers to related threads

thread ID

unique identifier assigned to a thread by the operating system

thread state

the current condition or status of a thread in the system (e.g., running, waiting, blocked)

register contents

the current values stored in the CPU registers used by the thread

thread priority

the assigned importance level of a thread, determining its scheduling order compared to other threads

multicore

refers to a CPU architecture that integrates multiple processing cores onto a single chip, or within a single system, enabling parallel execution of tasks

data parallelism

a computational technique where subsets of identical data are distributed across multiple processing cores, each core performing the same operation simultaneously on its subset of data

task parallelism

a computational approach where tasks or threads are distributed across multiple processing cores, with each task executing a unique operation independently, often on different or related data sets

fork()

a system call that creates a new process by duplicating the existing process

exec()

a system call that replaces the current process with a new program

signal

a way to alert a process about an event

default signal handler

the built-in handler for signals unless a process uses its own

pthread_kill()

a function in the POSIX threads (Pthreads) library used to send a signal to a specific thread within the same process

asynchronous procedure call (APC)

a function a thread sets to run when it gets a certain notice

thread cancellation

ending a thread before it finishes

pthread_cancel()

a function that requests the cancellation of a specific thread in Pthreads

What is the role of a process in a computer system?

Executing user and system tasks

Which state is a process when it is paused and is not currently being executed?

Waiting

How does a context switch impact CPU performance?

It temporarily suspends the current process to switch to another.

What is the purpose of scheduling queues in process management?

To manage the order of process execution

What is the result of a fork() system call in Unix?

Creation of a child process

Which mechanism allows processes to work together without interfering with each other?

Communication through interprocess mechanisms

Which method involves processes exchanging data by sending and receiving messages?

Message passing

How does synchronization ensure proper process execution?

By preventing simultaneous access to shared resources

Which type of thread is managed directly by the operating system?

Kernel-level

What is a significant advantage of using multithreading in applications?

It increases responsiveness and resource sharing.