Operating Systems Processes: The Process model c Process: an executing program, including the current values of the program counter, register, and variables One program counter Process Four program counters A B C B D DcBA D Time g Multiprogramming of 4 programs Conceptual model of 4 independent, sequential processes g Only one program active at any instant Gao Haichang, Software School, Xidian UniversityOperating Systems Gao Haichang , Software School, Xidian University 4 Processes: The Process Model  Multiprogramming of 4 programs  Conceptual model of 4 independent, sequential processes  Only one program active at any instant Process: an executing program, including the current values of the program counter, register, and variables