COP 4610 Lecture Notes - Lecture 2: Processor Register, Inetd, Program Counter
Document Summary
Have sufficient info to allow os to recreate the context to perfom the switch (using. Process = program and execution, stream of instruction executed in sqce which change machine state over time. A process can be defined by its state: it changes as instruction are being executed. Can be doing something or wait for some event. Technique used by os to allow multiple processes to execute at same time on single cpu. Cpu program counter (pc) allows first process to run for certain amount of time = few instructions executed. Then it does content-switch operation to run few instructions of process number 2 and so on Time slices are fairly short order of milisec. A given process is not running on cpu at all time. To make time slicing work : need to perfom context switches need memory to store this context : proces control block (pcb) used. (important data struct) ressources states listed above)