Process Control Block
Define the following:
1. Process is an instance of a program running in a computer. It is close in meaning to task, a term used in some operating systems. A process is also more than the program code, which is known as the text section.
2. Process Control Block is the representation of each process in the operating system. It is also called a task control block. This process control block contains many pieces of information associated with a specific process.
3. Thread is a basic unit of CPU utilization; it comprises a thread ID, a program counter, a register set, and a stack. It shares with other threads belonging to the same process its code section, data section, and other operating-system resources, such as open files and signals.
4. Process Scheduling embodies decision-making policies to determine the order in which active processes should compete for the use of processor.
5. Scheduler selects an available process (possibly from a set of available processes) for program execution of the CPU.
6. Buffering as reading and writing data from hard drive takes long time, so to improve the speed for data processing, the data next required by processor is stored in cache memory or CPU register.
7. Synchronization refers to one of two distinct but related concepts: synchronization of processes, and synchronization of data. Process synchronization refers to the idea that multiple processes are to join up or handshake at a certain point, in order to reach an agreement or commit to a certain sequence of action.
Enumeration:
1. 5 process states: New, Ready, Running, Blocked and Exit
New: A process has been created but has not yet been admitted to the pool of executable processes.
Ready: Process that are prepared to run if given an opportunity. That is, they are not waiting for anything except the CPU availability.
Running: The process that is currently executing.
Blocked: A process that cannot execute until a specified event such as an IO completion
1. Process is an instance of a program running in a computer. It is close in meaning to task, a term used in some operating systems. A process is also more than the program code, which is known as the text section.
2. Process Control Block is the representation of each process in the operating system. It is also called a task control block. This process control block contains many pieces of information associated with a specific process.
3. Thread is a basic unit of CPU utilization; it comprises a thread ID, a program counter, a register set, and a stack. It shares with other threads belonging to the same process its code section, data section, and other operating-system resources, such as open files and signals.
4. Process Scheduling embodies decision-making policies to determine the order in which active processes should compete for the use of processor.
5. Scheduler selects an available process (possibly from a set of available processes) for program execution of the CPU.
6. Buffering as reading and writing data from hard drive takes long time, so to improve the speed for data processing, the data next required by processor is stored in cache memory or CPU register.
7. Synchronization refers to one of two distinct but related concepts: synchronization of processes, and synchronization of data. Process synchronization refers to the idea that multiple processes are to join up or handshake at a certain point, in order to reach an agreement or commit to a certain sequence of action.
Enumeration:
1. 5 process states: New, Ready, Running, Blocked and Exit
New: A process has been created but has not yet been admitted to the pool of executable processes.
Ready: Process that are prepared to run if given an opportunity. That is, they are not waiting for anything except the CPU availability.
Running: The process that is currently executing.
Blocked: A process that cannot execute until a specified event such as an IO completion