Task switching based on assigned time slot

A task switching apparatus for switching execution of a task assigned to a time slot by switching time slots in a processor, the task switching apparatus comprising:

• an assigning unit configured to assign, on a one-to-one basis, each of a plurality of first tasks to a corresponding one of first time slots among a plurality of time slots within a predetermined period, and assign a plurality of second tasks different from the plurality of first tasks to a single second time slot among the plurality of time slots within the predetermined period, the plurality of first tasks each having an assignment time, the plurality of second tasks each having a priority classification, and the single second time slot not for being assigned to any of the plurality of first tasks;
• a time slot switching unit configured to switch time slots when an execution time of a task reaches an assignment time;
• a task selecting unit configured to select a first task from the plurality of first tasks assigned to the first time slots when said time slot switching unit switches a current time slot to a time slot other than the second time slot, and to select at least one second task from the plurality of second tasks assigned to the second time slot when the current time slot is switched to the second time slot;
• and
• a processor which executes the programs,
• wherein said task selecting unit is configured to select the at least one second task from among the plurality of second tasks according to the priority classification,
• wherein the assigning unit is further configured to:
• determine if a task in a received request for adding a task is a type associated with the plurality of first tasks or the plurality of second tasks,
• if the task in the received request is associated with the plurality of first tasks, the task is assigned to one of the first time slots only if a determined total sum of assignment time for the plurality of first tasks including the task in the received request does not exceed the predetermined period,
• if the task in the received request is associated with the plurality of second tasks, the task is added to the single second time slot.