 Solution

In a cooperative scheduler, a permanently runnable background operating-system process that never yields can monopolize the CPU. The timer service, smoothing operating-system process, and display may then fail to run even when their messages are ready. Correct message passing alone does not supply process scheduling.

Use timer-driven scheduling preemption, so an interrupt can force a context switch without cooperation. To give the measurement and display work bounded response despite background computation, use priority scheduling with the background operating-system process below the responsive services, or an explicit reservation policy. Round-robin scheduling gives CPU access among a fixed finite runnable set, but meeting a particular deadline additionally requires bounded service execution and sufficient CPU capacity.