CIS 390 Midterm Flashcards

Vocabulary flashcards for CIS 390 Midterm review.

fork() command in C++

When fork() is called, it creates a copy of the parent process. It returns 0 to the child process and the child's PID to the parent process.

fork() return to a Child

Returns 0.

fork() return to a Parent

Returns the child's PID.

fork() return on fail

Returns a negative number, likely -1.

wait() function

Waits for a child process to finish before continuing.

Variables before fork()

Available to both parent and child, but modifications in one process do not affect the other due to separate memory spaces.

Number of children: fork(); fork();

Four children will be created.

Data structure of a pipe

A structure that allows a child or parent to read and write data.

Index of the reading end in a pipe

When the parent process receives data from the child process

Variable type for a pipe

An int array of size 2.

Reading from an empty pipe

The program waits or stalls until data is put into the pipe.

Multiple processes reading from a pipe

False. Only one is able to read.

Transferring data back and forth using a single pipe

False.

Writing multiple data types into a pipe

It can cause confusion.

Closing pipes

To prevent processes from waiting indefinitely for data, stops processes.

CFS

Short for Central Focus Scheduling. Niceness values (-20 to 19) affect process scheduling, with higher values being 'better' for non-real-time tasks.

Niceness: Higher or Lower?

lower niceness is better.

Real Time Process Scheduling Types

FIFO (First In, First Out) and RR (Round Robin). FIFO runs until blocked or forced to stop. RR is similar to FIFO but gives time slices.

Priority of Scheduler Types

Real-time (RR) takes priority.

Signal Received

Acts as an interrupt to the process.

Catching Signals (SIGINT, SIGTERM)

To inform the user where the process has reached.

Generic Signal Without a Catch

The process gets killed.

Blocking or Catching Signals

True, some signals cannot be blocked or caught.

Function to Send a Signal in C

kill function.

Pointer

A variable that stores the memory address of another variable.

Pointer Code

int n = 2; int *nPtr = &n; *nPtr = *nPtr * 2;

Data Structures using Pointers

It may be faster.

fork() command in C++

When fork() is called, it creates a copy of the parent process. It returns 0 to the child process and the child's PID to the parent process.

fork() return to a Child

Returns 0.

fork() return to a Parent

Returns the child's PID.

fork() return on fail

Returns a negative number, likely -1.

wait() function

Waits for a child process to finish before continuing.

Variables before fork()

Available to both parent and child, but modifications in one process do not affect the other due to separate memory spaces.

Number of children: fork(); fork();

Four children will be created.

Data structure of a pipe

A structure that allows a child or parent to read and write data.

Index of the reading end in a pipe

When the parent process receives data from the child process

Variable type for a pipe

An int array of size 2.

Reading from an empty pipe

The program waits or stalls until data is put into the pipe.

Multiple processes reading from a pipe

False. Only one is able to read.

Transferring data back and forth using a single pipe

False.

Writing multiple data types into a pipe

It can cause confusion.

Closing pipes

To prevent processes from waiting indefinitely for data, stops processes.

CFS

Short for Central Focus Scheduling. Niceness values (-20 to 19) affect process scheduling, with higher values being 'better' for non-real-time tasks.

Niceness: Higher or Lower?

Higher niceness is better.

Real Time Process Scheduling Types

FIFO (First In, First Out) and RR (Round Robin). FIFO runs until blocked or forced to stop. RR is similar to FIFO but gives time slices.

Priority of Scheduler Types

Real-time (RR) takes priority.

Signal Received

Acts as an interrupt to the process.

Catching Signals (SIGINT, SIGTERM)

To inform the user where the process has reached.

Generic Signal Without a Catch

The process gets killed.

Blocking or Catching Signals

True, some signals cannot be blocked or caught.

Function to Send a Signal in C

kill function.

Pointer

A variable that stores the memory address of another variable.

Pointer Code

int n = 2; int *nPtr = &n; *nPtr = *nPtr * 2;

Data Structures using Pointers

It may be faster.

Data Structures using Pointers

It may be faster.

Real Time Process Scheduling Types

FIFO (First In, First Out) and RR (Round Robin). FIFO runs until blocked or forced to stop. RR is similar to FIFO but gives time slices.

Fork() returns to child

Returns 0 to the child process

Function to sena a signal in C

kill function

The process gets killed

Generic signak without a catch

False

Multiple process reading from a pipe is ?

Higher niceness is better

Niceness: Higher or Lower?