Portable electronic device

A portable electronic device comprising:

• a first memory which stores an operating system program;
• a second memory which stores an application program;
• a third memory which stores a file;
• a channel management unit which causes the operating system program to manage a plurality of channels to access the file stored in the third memory;
• an access order management unit which manages, as an access order, an order that each channel managed by the channel management unit has set the file stored in the third memory in a current state;
• an access order updating unit which, if a first channel managed by the channel management unit cancels the current state of the file stored in the third memory, excludes the first channel from an access order management target for the file and moves up the access orders of all channels next to the first channel;
• a providing unit which provides, to the application program which is going to access the file stored in the third memory, data representing the access order of each channel for the file;
• and
• an access control unit which controls access to the file via a channel to which the operating system program has assigned the application program which has received the data representing the access order from the providing unit.