refers to an instance of a program that is being executed. A process contains the program code and its current activity, including the program counter, registers, and variables. Processes are fundamental to multitasking operating systems, as they allow multiple programs to run simultaneously

A process goes through various states during its execution. These states represent different stages of execution, ranging from being idle to actively using the CPU. Here are the common

A process is in the _____ state when it is being created. The operating system allocates resources (e.g., memory) for the process during this stage

The process is loaded into main memory and is ready to run, but it is waiting for the CPU to become available. Processes in the ready state are waiting for scheduling to get CPU time

Once a process is given the CPU, it moves to the _______ state. In this state, the process is actively executing instructions

A process moves to the _________ state if it cannot proceed until some event occurs, such as waiting for input/output (I/O) operations to complete. For example, if a process is waiting for user input, it becomes blocked until that input is provided.

Sometimes a process may be __________ from memory to free up space for other processes. The process is still ready or waiting, but it has been moved to secondary storage (like a hard drive). It remains inactive until it's swapped back into main memory.

Once the process has finished executing, it enters the ________ state. All resources used by the process (memory, files, etc.) are released, and the process is removed from the system's

After being created, the process is admitted into the ready queue

When the CPU scheduler selects the process for execution, it moves from ______-_____

If a process is preempted (interrupted to give another process CPU time), it returns to the ready state.

Once the event the process was waiting for occurs (e.g., I/O completes), the process moves back to the ready state

When a process finishes its execution, it transitions to the terminated state.

interact directly with the user, like applications that are currently being used

run without user interaction, often performing system maintenance or other tasks (e.g., a virus scan or system update)

A parent process creates one or more child processes. The child processes can execute independently, but the parent can control or monitor them.

is a process that has completed execution but still has an entry in the process table because its parent hasn't yet read its exit status. It is a defunct process that doesn't use resources, but it is still listed in the process table

occurs when two or more processes are stuck, each waiting for the other to release resources, resultibg in a cycle of dependency and none of the processes being able to proceed

what are the 4 causes of deadlock

only one process can cause a resource at a time

process holding resources are waiting for others

resources cannot be forcibly taken a process

a cycle processes exist where each is waiting for a resource held by another in a cycle

Methods in preventing deadlocks

allow resources to be shared by multiple processes

require processes to request all necessary resources at once or release held resources before requiring new ones

permit the system to forcibly take resources from process when needed

impose a total ordering on resource request to avoid circular dependencies between processes

2 types of deadlock detection

it represents the current allocation state of the resource and processes

uses graph to represents dependecies between process and waiting resources

4 Types of Deadlock Recovery

identifying and terminationg processes involved freeing up resources

complex method used to solved deadlock by identifying and selecting resource involved in deadlock, then suspending the process

real time system method that shifts process priorities to avoid deadlocks

database system method that resolves deadlocks by reverting transactions to a previous state

The process of handling a computer's memory resources effectively, involving allocation, tracking, and deallocation of memory space to optimize performance and system stability.

Small, fast storage locations in the CPU for temporary data.

Faster memory that stores frequently accessed data to speed up processing,

Volatile memory for active programs and data

Non-volatile storage (eg, HDD, SSD) for long-term data.

2 types of allocation

Allocating fixed blocks of memory for processes.

Allocating variable-sized memory blocks based on process needs.

Fragmentation (2)

Free memory is split into small, non-contiguous blocks

Allocated memory blocks may be larger than necessary

A technique that allows processes to use more memory than is physically available by utilizing disk space as an extension of RAM.

Moving processes between main memory and disk to optimize space and enable multitasking

Entire process swapped out

Only parts of a process swapped out

Prevents one process from accessing another process's memory space, ensuring stability and security.

An automatic memory management technique that identifies and reclaims memory from objects no longer in use, preventing memory leaks.

Associating a file or device directly with a portion of memory, allowing programs to interact with memory as if it were a file

The range of memory addresses that a process can use, typically isolated for protection and efficiency

A hardware component that translates virtual addresses to physical addresses and enforces memory protection.

Divides memory into fixed-size partitions for process allocation, leading to potential internal fragmentation

Allocates variable-sized partitions based on process requirements, reducing internal fragmentation but possibly causing external fragmentation

Divides memory into fixed-size pages, allowing non-contiguous allocation and eliminating external fragmentation.

Combines paging, and segmentation to allow larger processes to run systems with limited physical memory

Optimizes memory by moving processes in and out of memory, facilitating multitasking

Enables programs to read from and write to memory as if interacting with files, streamiining file operations

Automatically identifies and reclaims memory occupied by unreferenced objects, preventing leaks and managing memory efficiently

Allocates memory blocks that are powers of two, splitting larger blocks imo "buddies" when necessary.

Loads pages into memory only when required, reducing initial load time and optimizing memory usage.

Techniques aimed at managing the degree of multiprogramming and optimizing page usage to prevent excessive swapping that degrades performance

A technique to store frequently accessed data in a small, fast memory area to improve access speed.