Process

Process

1. A proccess consists of: state of execution, parts and temporary holding area and special hardware.

2. a process is the state of a program when executing loaded in memory

3. there are 3 types of state

   • text and data: static static when process first loads
   • heap: dynamically created during execution
   • stack: grows and shrinks

4. For the OS to know what the process is doing the CPU has to know where in the instruction sequence is, that is called the program counter.

5. A process control block (PCB) is a data structure that the OS maintains of everyone of the processes that it manages (program counter, stack pointer, CPU registers, memory mappings)

6. The PCB is works by having to process, P1 & P2 when P1 is running and P2 is idle, the CPU holds the information of P1 in PCPb P1. When P1 is idle and P2 is running CPU contains the information of P1 and adds the infromation of P2 in PCB.P2.

7. The context switch consists of switching the CPU from the context of one process (P1) to the context of another (P2).