Processes (Prelims) Flashcards
It can be defined in different ways, depending on its actual composition or utilization.
Process
Basic definitions of process:
- Program in execution
- Entity that can be assigned to and executed on a processor
- Unity of activity that executes a sequence of instructions
- Environment that consists of a number of elements for executing a user-level program
This can be shared with other processes that are executing the same program
Program code
It is associated with the program code
Set of data
Two (2) essential elements of a process:
- program code
- set of data
It can execute multiple processes at a time, thus supporting thousands of processes on a single system
Kernel
What are the five (5) process state?
- New
- Ready
- Running
- Waiting
- Terminated
It is unique for each process
Identifier
It indicates the current activity of a process
Process State
Process is being created
New
Process is waiting to be assigned to a processor
Ready
The instructions are being executed
Running
The process is waiting for a particular event to occur
Waiting
It refers to the priority level relative to the other processes
Priority
The process has finished the execution
Terminated
It indicated the address of the next instruction to be executed for a particular process
Program counter
It contains pointer to program codes and data associated with the process, including any memory blocks shared with other processes
Memory pointer
These are the data present in a processor’s registers during process execution
Context Data
This includes different information associated with the input/output status of a process, such as the outstanding I/O requests and I/O devices assigned to the process
I/O status information
This includes different tracking information associated with the process, such as the amount of processor time, the clock time used, and time limits.
Accounting information
It is called to the elements of a process are stored in a data structure. The core concept is that it contains sufficient information to information, so it is possible interrupt a running process and later resume the operation as if no interruption occurred.
Process control block
