Does Teachers Keep Students During Recess

Does the teacher keep students in during recess/lunch? Why? My cooperating teacher does keep students in for lunch and recess, usually every day. For homework, she has students record in their agenda what they need to do for the night, week, or weekend. When students return the next day, the teacher checks to see if they are ready to turn in any homework that is due. If students are missing homework, she gives them a one day grace period. If a student still has not turned in homework after this one day grace period, the student is to stay in for lunch and lunch recess. She does not allow them to finish their homework during this time. Another reason she keeps students in for lunch and lunch recess, is if students have not finished classwork.
She gives them the time during lunch, to work on any unfinished class work. I have only seen one student stay in for lunch related to behavior. This is not a usual occurrence.
How does the teacher handle interruptions during instruction….from students, other teachers, phone, knock on the door? Usually when a student interrupts the teacher during instruction, she reminds them they must raise their hand to speak, and that they must wait to do so until after she is speaking. She reminds students there is no talking while she is talking, and that they must only be listening. If other teachers come into the room to ask her a question or for other reasons, she usually stops what she is doing and puts her class on hold to speak to the teacher. If an interruption such as the phone ringing occurs, a student answers the phone and delivers the message to the teacher.