Which of the following statements about synchronous and asynchronous I/O is…
2009
Which of the following statements about synchronous and asynchronous I/O is NOT true?
- A.
An ISR is invoked on completion of I/O in synchronous I/O but not in asynchronous I/O
- B.
In both synchronous and asynchronous I/O, an ISR (Interrupt Service Routine) is invoked after completion of the I/O
- C.
A process making a synchronous I/O call waits until I/O is complete, but a process making an asynchronous I/O call does not wait for completion of the I/O
- D.
In the case of synchronous I/O, the process waiting for the completion of I/O is woken up by the ISR that is invoked after the completion of I/O
Attempted by 120 students.
Show answer & explanation
Correct answer: A
The correct answer identifies the false statement regarding I/O models. While synchronous I/O involves a process waiting for completion, asynchronous I/O also utilizes Interrupt Service Routines (ISRs) to signal when an operation is finished. Therefore, the statement claiming ISRs are not invoked in asynchronous I/O is incorrect, as ISRs serve as a completion signal mechanism in both models.