Patent ID: 8549526

Claim:
An access control apparatus that controls an I/O device to perform a file processing of access requests in a predetermined order, said access control apparatus comprising: a task input part which inputs access requests from multiple tasks to cause said I/O device to perform said file processing; a file priority management part which stores and manages information about file priorities, each file being assigned a file priority in correspondence with a processing priority; a file priority obtaining part which obtains a file priority corresponding to a file related to an access request among the access requests, from said file priority management part; a queue management part which includes multiple queues for which the processing priorities corresponding to the file priorities are set and causes the access request to be stored in any of the multiple queues corresponding to the file priority obtained by said file priority obtaining part; an access request sending part which obtains the access requests stored in the queues in an order based on the processing priorities set for the queues and sends the access requests to said I/O device on an access-target file side; and a task priority management part which stores and manages task information about task priorities indicating processing priorities of tasks, and wherein said file priority management part obtains file priorities corresponding to the task priorities from said task management part and stores the file priorities obtained in said file priority management part, wherein when receiving an access request from the task, said task priority management part stores a task priority of the task corresponding to the access request; said file priority management part determines a new current priority based on a current priority used currently, which is a file priority used when the access request stored in the queue is stored into the queue, the task priority and the file priority; and said queue management part moves the access request already stored in the queue to a queue corresponding to the new current priority determined by said file priority management part, and stores the access request which is not stored in the queue into the queue corresponding to the new current priority.