Process Management:

Process management is a fundamental aspect of operating systems that involves the management of processes, which are instances of executing programs. Here's an overview:

Process Definition: A process is a program in execution. It includes the program counter, register set and memory space. Processes may also have associated resources such as open files, network connections, and allocated memory.

1. Process Creation:

2. Fork: In Unix-like systems, the fork() system call is used to create a new process, which is a copy of the parent process. After forking, the child process can execute a different program using the exec() family of system calls.

3. 
   

4. Spawn: In Windows, the spawn() or Create Process() function is used to create a new process. Similar to fork(), the child process can start executing a different program than the parent.

5. 
   

6. Process Termination:

   • Exit Status: When a process terminates, it returns an exit status to the operating system. This status indicates whether the process was completed successfully or encountered an error.
   • Zombie Process: If a parent process does not wait for its child process to terminate and collect its exit status, the child process becomes a zombie process, occupying system resources until it is reaped by the parent process.

7. 
   

8. Process Scheduling:

   • Preemptive Scheduling: In preemptive scheduling, the operating system can interrupt the currently running process and allocate the CPU to another process based on priority or time quantum.
   • Non-preemptive Scheduling: In non-preemptive scheduling, a process relinquishes the CPU only after completing its execution or voluntarily yielding control to the operating system.

9. 
   

10. CPU Scheduling Algorithms:

    • First-Come, First-Served (FCFS): Processes are executed in the order they arrive.
    • Shortest Job Next (SJN): The process with the shortest CPU burst time is selected next.
    • Round Robin (RR): Each process is assigned a fixed time slice (time quantum) and executed cyclically.
    • Priority Scheduling: Processes are executed based on priority levels assigned to them.
    • Multi-Level Queue Scheduling: Processes are divided into different queues based on priority, and each queue has its own scheduling algorithm.

11. 
    

12. Inter-Process Communication (IPC):

    • Shared Memory: Processes can communicate by sharing a portion of memory.
    • Message Passing: Processes exchange messages through system-provided message queues.
    • Pipes: A unidirectional communication channel between two processes.
    • Sockets: Communication between processes over a network.

13. 
    

14. Concurrency and Synchronization:

    • Critical Section: A segment of code that must be executed atomically to prevent race conditions.
    • Mutexes: Mutual exclusion locks used to protect critical sections.
    • Semaphores: A synchronization primitive used for signaling between processes.
    • Monitors: High-level synchronization constructs that encapsulate data and procedures to ensure mutual exclusion.

Process management is a complex and critical aspect of operating systems, involving various mechanisms and algorithms to efficiently utilize system resources, provide fairness, and ensure stability and responsiveness. Operating systems implement sophisticated techniques to manage processes effectively in multi-tasking environments.