Can you explain Process & its States?

In computer science, a process is an independent, self-contained unit of execution that runs in its own address space. It is a program in execution, and multiple processes can run concurrently on a computer system. Each process has its own memory space, system resources, and state.

States of a Process:

The life cycle of a process is typically divided into several states. The exact terminology and number of states may vary slightly depending on the operating system, but the general concept remains consistent. Here are the common states:

• New: The process is being created but has not yet been admitted to the pool of executable processes. Resources are being allocated to the process.
• Ready: The process is prepared to run and is waiting for the CPU to be assigned to it. It is in the queue of processes that are ready to execute.
• Running: The process is being executed by the CPU. It is the active state where instructions are being executed.
• Blocked (Wait or Sleep): The process is temporarily inactive. It is waiting for an event to occur, such as user input, the completion of I/O operations, or the availability of a resource.
• Terminated: The process has finished its execution. In this state, the process is typically removed from the system, and its resources are deallocated.

State Transitions:

Processes can transition between these states based on events and system scheduling. Here are common state transitions:

• A new process moves to the ready state after initialization.
• A ready process moves to the running state when the CPU is assigned to it.
• A running process moves to the blocked state when it needs to wait for an event.
• A blocked process moves back to the ready state when the event it was waiting for occurs.
• A running process may move to the ready state when its time quantum (if using a time-sharing system) expires.
• A terminated process is removed from the system.

Process Control Block (PCB):

The operating system maintains information about each process in a data structure called the Process Control Block (PCB). The PCB contains details such as process state, program counter, registers, memory allocation, and other relevant information needed for the operating system to manage the process.

Understanding the states of a process and their transitions is crucial for designing efficient and responsive computer systems. The operating system's scheduler is responsible for managing these transitions and ensuring fair and effective utilization of system resources.

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