Question

Given the three thread states: running, runnable (i.e., ready), and blocked (i.e., waiting), state which of the six possible thread transitions are allowed, and which ones are not. Also, for each case, provide an example of how the transition occurs, or a reason why it cannot (as a justification for each of your answers). Assume Mesa-style scheduling.

Answer 1

Answer:

Ready-Running

Running-Ready

Running-Blocked

Blocked-Ready

Ready-Blocked

Blocked-Running

Explanation:

In monitor synchronisation, one of the scheduling approaches is the Mesa style scheduling.

The Mesa style scheduling in a Mesa monitor, the released thread due to a signal is also in the inactive state. Note that those inactive threads had the lock previously; but, they are unable to re-acquire it.

There are six ways it can carry out scheduling, they are as shown in the answer.

Please kindly check attachment for details and drawing.