CSC3B CH 3 - Review Questions

Process

What are the four components of a process?

• Text section: program code itself

• Stack: temporary data (function parameters, return addresses, local variables)

• Data section: global variables

• Heap: contains memory dynamically allocated during run-time

Provide at least three possible states a process may be in.

• New - The process is being created

• Running - Instructions are being executed.

• Waiting - The process is waiting for some event to occur (such as an I/O completion or reception of a signal).

• Ready - The process is waiting to be assigned to a processor.

• Terminated - The process has finished execution.

What is a Process Control Block (PCB)?

is a data structure used to store many pieces of information associated with a specific process incl. process state, program counter and other details necessary for process management.

What is another term for process?

task/job

True or False? Most operating systems allow a process to have multiple threads.

TRUE, most modern operating systems have extended the process concept to allow a process to have multiple threads

What is the role of the process scheduler?

Process scheduler selects an available process (possibly from a set of several available processes) for program execution on the CPU.

What is the degree of multiprogramming?

The number of processes in memory at the same time.

What is the term that describes saving the state of one process, and restoring the state of another?

Context switch.

What is a process identifier (PID)?

is a unique integer numerical ID assigned by the operating system to each process for identification and management.

What system call creates a process on UNIX systems?

the fork() system call.

What system call creates a process on Windows systems?

Processes are created in the Windows API using the CreateProcess() function

What system call terminates a process on UNIX systems?

the exit() system call terminates a process.

What is the name of the process that UNIX and Linux systems assign as the new parent of orphan processes?

init process

What are the two fundamental models of interprocess communication?

shared memory and message passing.

What are the two system calls used with message-passing systems?

1. send(message)

2. receive(message)

True or False? Message passing is typically faster than shared memory

How must shared memory behave for a rendezvous to occur?