Operating Systems Process Management

Study Notes

Process management is a crucial aspect of operating systems that deals with the creation, execution, and termination of processes.

Process: A program in execution, including the current activity, memory, and system resources.
Thread: A lightweight process that shares memory and resources with other threads within the same process.
Parent Process: A process that creates a new process.
Child Process: A process created by a parent process.

Newborn: A process is created and is being initialized.
Running: A process is currently executing instructions.
Waiting: A process is waiting for a resource or event to occur.
Ready: A process is waiting for the CPU to become available.
Zombie: A process that has finished execution but still has an entry in the process table.
Sleeping: A process that is waiting for a specific event or signal.

Scheduling Algorithms: Determine the order in which processes are executed by the CPU.
- First-Come-First-Served (FCFS): The process that arrives first is executed first.
- Shortest Job First (SJF): The process with the shortest burst time is executed first.
- Priority Scheduling: Processes are assigned a priority, and the highest priority process is executed first.
- Round Robin (RR): Each process is given a fixed time slice (time quantum) to execute before the next process is scheduled.

Synchronization: The coordination of processes to ensure that they access shared resources without conflicts.
Critical Section: A section of code that accesses shared resources and must be executed by only one process at a time.
Synchronization Mechanisms:
- Mutex: A lock that allows only one process to access a shared resource.
- Semaphore: A counter that limits the number of processes that can access a shared resource.
- Monitor: A high-level synchronization mechanism that provides a safe and efficient way to access shared resources.

Inter-Process Communication (IPC): The exchange of data or information between processes.
IPC Mechanisms:
- Pipes: A unidirectional communication channel between two processes.
- Message Queues: A buffer that stores messages sent between processes.
- Shared Memory: A shared region of memory that can be accessed by multiple processes.
- Sockets: A communication endpoint that allows processes to communicate over a network.

Process management deals with the creation, execution, and termination of processes in an operating system.

A process is a program in execution, including current activity, memory, and system resources.
A thread is a lightweight process that shares memory and resources with other threads within the same process.
A parent process creates a new process, and a child process is created by a parent process.

A newborn process is being initialized after creation.
A running process is currently executing instructions.
A waiting process is waiting for a resource or event to occur.
A ready process is waiting for the CPU to become available.
A zombie process has finished execution but still has an entry in the process table.
A sleeping process is waiting for a specific event or signal.

Scheduling algorithms determine the order in which processes are executed by the CPU.
First-Come-First-Served (FCFS) scheduling executes the process that arrives first.
Shortest Job First (SJF) scheduling executes the process with the shortest burst time first.
Priority Scheduling executes the process with the highest priority first.
Round Robin (RR) scheduling gives each process a fixed time slice (time quantum) to execute before the next process is scheduled.

Synchronization coordinates processes to access shared resources without conflicts.
A critical section is a section of code that accesses shared resources and must be executed by only one process at a time.
Mutex is a lock that allows only one process to access a shared resource.
Semaphore is a counter that limits the number of processes that can access a shared resource.
Monitor is a high-level synchronization mechanism that provides a safe and efficient way to access shared resources.

Inter-Process Communication (IPC) is the exchange of data or information between processes.
Pipes are a unidirectional communication channel between two processes.
Message Queues are a buffer that stores messages sent between processes.
Shared Memory is a shared region of memory that can be accessed by multiple processes.
Sockets are a communication endpoint that allows processes to communicate over a network.