Computer Science Processes and States

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Questions and Answers

What is the maximum number of elements that can be effectively used in the bounded buffer implementation described?

BUFFER_SIZE - 1 (correct)

BUFFER_SIZE + 1

BUFFER_SIZE / 2

BUFFER_SIZE

What occurs in the producer process when the buffer is full?

The producer continues producing without restriction.

The producer fills the buffer beyond its limit.

The producer overwrites the oldest item in the buffer.

The producer halts and waits. (correct)

In the consumer process, what condition leads to waiting?

When the inventory exceeds BUFFER_SIZE.

When the buffer is completely empty. (correct)

When the buffer is partially filled.

When more items are produced than consumed.

What is a major concern when processes use shared memory for communication?

Ensuring user processes synchronize their actions. Signup and view all the answers

How does the consumer retrieve the next item from the buffer?

By checking the 'out' pointer and retrieving the respective item. Signup and view all the answers

What is a process?

A program in execution. Signup and view all the answers

Which of the following states indicates that a process is being created?

New Signup and view all the answers

What essential information does a Process Control Block (PCB) not contain?

User input data Signup and view all the answers

Which of the following best describes the 'waiting' state of a process?

The process is waiting for some event to occur. Signup and view all the answers

What type of information is included in the accounting information of a PCB?

Clock time elapsed since start. Signup and view all the answers

Which part of a process contains dynamically allocated memory during runtime?

Heap Signup and view all the answers

In which state is a process when it is prepared to be executed but not currently running?

Ready Signup and view all the answers

How can a user initiate the execution of a program?

By GUI mouse clicks or command line entry. Signup and view all the answers

What does the term 'interprocess communication' refer to?

The mechanism for processes to communicate and synchronize. Signup and view all the answers

How many processes can a single program have running simultaneously?

Multiple, depending on the system. Signup and view all the answers

What is one of the main reasons for processes to cooperate?

To enable computation speedup Signup and view all the answers

Which interprocess communication model allows multiple processes to share a memory space?

Shared memory Signup and view all the answers

What distinguishes a cooperating process from an independent process?

Independent processes cannot be affected by others Signup and view all the answers

In the producer-consumer problem, what does a bounded buffer assume?

There is a fixed size for the buffer Signup and view all the answers

What is a benefit of using interprocess communication (IPC)?

It facilitates data exchange between cooperating processes Signup and view all the answers

Which of the following is NOT a reason for cooperating processes?

Security enhancement Signup and view all the answers

What type of renderer is created for each website opened to minimize the effect of security exploits?

New renderer Signup and view all the answers

Which of the following best describes the relationship between cooperating processes?

They can affect or be affected by each other Signup and view all the answers

What is a key characteristic of direct communication between processes?

Each process must name the other explicitly. Signup and view all the answers

In indirect communication, what is the main function of a mailbox?

To hold messages sent between processes. Signup and view all the answers

Which of the following statements about communication links is true?

Each pair of processes involved in direct communication has exactly one link. Signup and view all the answers

Which primitive operation is used to send a message to a mailbox?

send(A, message) Signup and view all the answers

What happens when multiple processes share the same mailbox?

Some processes may receive messages while others do not. Signup and view all the answers

What type of communication can involve multiple processes accessing a single link?

Indirect communication Signup and view all the answers

What is a distinguishing feature of automatic link establishment in direct communication?

The link is created when two processes begin communication. Signup and view all the answers

In the context of message passing, which scenario describes synchronous communication?

Sender waits for an acknowledgment from the receiver. Signup and view all the answers

What happens if a parent process terminates without invoking the wait() system call?

The child process becomes a zombie. Signup and view all the answers

What is a reason a parent process might terminate a child process using the abort() system call?

The task assigned to the child is no longer required. Signup and view all the answers

What does the wait() system call return?

Status information and the pid of the terminated process. Signup and view all the answers

In a multiprocess architecture like Google Chrome, what is the primary function of the browser process?

To handle user interface and I/O operations. Signup and view all the answers

What is meant by cascading termination in operating systems?

When a parent terminates, all its children and their descendants are also terminated. Signup and view all the answers

What is an orphan process?

A child process that is still running while its parent has terminated. Signup and view all the answers

Which of the following describes the function of the renderer process in Google Chrome?

It renders web pages and handles HTML structures. Signup and view all the answers

What occurs if a process becomes a zombie?

It waits indefinitely for the parent to retrieve its status. Signup and view all the answers

Study Notes

The Process Concept

A program in execution is a process. Processes have multiple parts: program code, current activity (program counter and registers), stack (for temporary data, function parameters, local variables), data section (for global variables), and heap (for memory dynamically allocated during runtime).
A program is a passive entity stored on disk, a process is active. An executable file must be loaded into memory to become a process.
Multiple processes can run the same program.

Process State

Processes transition between different states as they execute.
The process states are: new, running, waiting, ready, and terminated.
The new state is when a process is being created.
The running state is when the process is executing instructions.
The waiting state is when a process is waiting for an event to occur (e.g., I/O completion).
The ready state is when a process is waiting to be assigned to a processor.
The terminated state is when the process has finished execution.

Process Control Block (PCB)

The PCB stores information about each process.
This information includes the process state, program counter, CPU registers, CPU scheduling information, memory management information, accounting information, and I/O status information.

Process Termination

Processes can be terminated by the operating system or by the parent process.
The parent process can terminate a child process using the abort() system call.
Reasons for terminating a process include resource exhaustion, task completion, and parent process termination.
When a process terminates, its resources are deallocated by the operating system.
If a parent process terminates, its child processes may need to be terminated as well. This is called cascading termination.
A process that has terminated but is still waiting for its parent to collect its exit status is called a zombie process.
A process that has lost its parent is called an orphan process.
The wait() system call allows a parent process to wait for the termination of a child process and collect its exit status.

Multiprocess Architecture - Chrome Browser

The Google Chrome browser utilizes multiple processes to improve stability and security.
The browser process manages the user interface, disk and network I/O.
The renderer process renders web pages, dealing with HTML and JavaScript. Each website opened has its own renderer process, which runs in a sandbox to restrict disk and network I/O and minimize the impact of security exploits.
Plug-in processes also run separately, one for each type of plug-in.

Interprocess Communication (IPC)

IPC is a mechanism for processes to communicate with each other.
Two main models of IPC:
Shared memory allows processes to share a region of memory.
Message passing involves processes exchanging messages with each other.

Producer-Consumer Problem

A classic example of cooperating processes is the producer-consumer problem.
One or more producer processes generate data that is consumed by one or more consumer processes.
A buffer is used to store the data, and it can be either unbounded or bounded.

Bounded Buffer Solution

A bounded buffer solution restricts the buffer size to a fixed number of elements.
The producer process must wait when the buffer is full, and the consumer process must wait when the buffer is empty.
The solution can be implemented using shared memory.

Message Passing (cont.)

An implementation of message passing communication can be implemented using shared memory, a hardware bus, or a network.
The communication links themselves can be direct or indirect, synchronous or asynchronous, and automatic or explicit buffering.

Direct Communication

In direct communication, processes explicitly name each other when sending and receiving messages.
The send() primitive is for sending messages to a specific process.
The receive () primitive is for receiving messages from a specific process.
Direct communication links are typically bidirectional.

Indirect Communication

In indirect communication, processes communicate through mailboxes or ports.
Each mailbox has a unique ID, and processes can communicate only if they share a mailbox.
Links can be established by sharing mailboxes.

The Operating System

The operating system manages processes and provides resources for them.
It creates and terminates processes, schedules them for execution, and handles interprocess communication.

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Description

Explore the concept of processes in computer science, including the various components of a process and the different states it can be in during execution. This quiz will test your understanding of process management and the transitions between states such as new, running, waiting, ready, and terminated.