Question

Question 3 (1 points): Suppose a mouse controller is connected to the processor via the memory bus. Whenever a mouse button is pressed or released or the mouse is moved, the mouse controller adds an a record of that event to a small buffer it maintains and signals the processor to trigger an interrupt. Suppose a process on this system can make a system call that waits for a mouse click to occur. (That is, the system call only cares about mouse clicks that occur after the system call is started.) To implement this system call, what would be the best choice for the device driver? A. O the device driver should mark the process as not runnable from the system call handler and later, from its interrupt handler mark the process as runnable again B. O the device driver should write the address of the system call's return value into the mouse controller's buffer, then context switch to another process C. the device driver should read the device controller's buffer of events in a loop when it is called from the system call handler until it detects a mouse click in it

Answer 1

Date ........ MON TUE WED THU FRI SAT SUN OOOOOOO f Ans (a. Concept In question, interrupt driven TO (Mouse) TO devices Device generates generates (mouse click) Buffer get Data process that get Data from Buffer Device Controller place data in MM with the help of buses. AND malce system call Memory generate 17 Process make system call and device! driver will maok process not runnable 2) whenever event access, it will get stored in device buffer 37 Controller will get the data from buffer & place it in MM & generates interrupt. 4 By this interrupt process will be sunnabble again & get the dada " option is correct -