Patent ID: 7327484

Claim:
A data processing apparatus comprising: a data reception section for receiving data; a data storage section for storing the data received by said data reception section; a processing section for processing the data stored in said data storage section; a nullification section for nullifying the data stored in said data storage section; a history storage section for storing a usage history; a setting section for setting up that prority should be imparted to either the processing to be performed by said processing section onto not-yet-processed data or the nullification to be performed by said nullification section onto already-processed data depending on the contents of the usage history stored in said history storage section; an execution section for performing with priority either the processing of not-yet-processed data or the nullification of already-processed data, depending on the setting result of said setting section; a priority instruction reception section for receiving a priority instruction for imparting priority to either the processing of not-yet-processed data or the nullification of already-processed data, wherein, in response to the priority instruction received by said priority instruction reception section, said execution section performs with priority either the processing of not-yet-processed data or the nullification of already-processed data; wherein said history storage section stores, as a usage history, which of the processing of not-yet-processed data and the nullification of already-processed data has been performed with priority in response to the priority instruction; and wherein, depending on a result of comparison between the number of times of imparting priority to the nullification of already-processed data and the number of times of imparting priority to the processing of not-yet-processed data which are stored as the usage history, said setting section sets up that priority should be imparted to either the processing of not-yet-processed data or the nullification of already-processed data.