Buffering device and control method thereof

A control method executed by a buffering device of data units, the control method comprising:

• holding, in a first holding unit, information on a write number and information on a read number for each of a plurality of grouping criteria, each of the grouping criteria including a priority of the data units as one grouping parameter;
• holding at least one of the data units in a second holding unit, each of the data units corresponding to any of the plurality of grouping criteria;
• forming a holding address, which causes the second holding unit to hold the written data units, based on the information on the write number of the grouping criteria corresponding to the written data units;
• and
• forming an output address of the second holding unit, in which the read data units are held, based on the information on the read number of the grouping criteria corresponding to the read data units.

A computer readable storage medium causing to a buffering device of data units to perform a processing, the medium comprising:

• holding, in a first holding unit, information on a write number and information on a read number for each of a plurality of grouping criteria, each of the grouping criteria including a priority of the data units as one grouping parameter;
• holding at least one of the data units in a second holding unit, each of the data units corresponding to any of the plurality of grouping criteria;
• forming a holding address, which causes the second holding unit to hold the written data units, based on information on a write number for the grouping criteria corresponding to the written data units;
• and
• forming an output address of the second holding unit, in which the read data units are held, based on information on a read number for the grouping criteria corresponding to the read data units.