Os Process Management Questions Medium
A process control block (PCB) is a data structure used by an operating system to manage and keep track of each individual process running on a computer system. It is also known as a task control block or a process descriptor.
The PCB contains various pieces of information about a process, including:
1. Process ID (PID): A unique identifier assigned to each process by the operating system.
2. Process state: Indicates the current state of the process, such as running, ready, blocked, or terminated.
3. Program counter (PC): Stores the address of the next instruction to be executed by the process.
4. CPU registers: Contains the values of all CPU registers at the time of process interruption, allowing the process to resume execution from where it left off.
5. Memory management information: Includes information about the memory allocated to the process, such as the base and limit registers, which define the memory range accessible to the process.
6. Process priority: Determines the relative importance of a process and helps the operating system schedule processes accordingly.
7. Parent process ID: Identifies the process that created the current process, establishing a hierarchical relationship between processes.
8. Open file descriptors: Keeps track of the files and devices opened by the process, including their current position and access mode.
9. Accounting information: Records statistics about the process, such as CPU usage, execution time, and memory usage.
10. Inter-process communication (IPC) information: Stores details about any communication channels or shared resources used by the process to interact with other processes.
The PCB is crucial for the operating system to manage and control processes effectively. It allows the operating system to switch between processes, allocate resources, schedule execution, and handle process synchronization and communication.