Which CPU scheduling method ensures a process runs to completion without interruption?

The method of CPU scheduling that guarantees a process runs to completion without interruption is nonpreemptive scheduling. In this approach, once a process is given control of the CPU, it will continue to execute until it either completes its task or voluntarily relinquishes control, such as by entering a waiting state for I/O operations. This ensures that processes are not interrupted by the scheduler and can complete their tasks without any context switching.

In contrast, preemptive scheduling allows the operating system to interrupt a currently running process in favor of another, which can lead to incomplete execution of certain tasks. Time-sharing and round-robin scheduling both involve dividing CPU time among processes, allowing for their interleaved execution, which also means processes can be interrupted before they finish. Thus, nonpreemptive scheduling is the only method that allows a process to run uninterrupted to completion.