PURPOSE: To prevent the deterioration of performance by once interrupting a transmission/reception operation so as to control the other application by a communication control part when a buffer is exhausted, and resuming an interrupted operation when the buffer can be acquired, eliminating an unneces sary CPU load and executing the high speed operation of the plural applications.
CONSTITUTION: The communication control part 12 informs a buffer management part 21 of a buffer acquirement request when data transmission/reception is requested. When the buffer management part 21 cannot acquire the buffer, an entry address is stored in a buffer acquirement request holding queue 22, the communication control part 12 is informed of the exhaustion of the buffer. The communication control part 12 sets the state flag of a control table 13 to be 'interrupted' and executes the other processing. When the buffer management part 21 can acquire the buffer, buffer acquirement is transferred to the communication control part 12 of the entry address in the buffer acquirement request holding queue 22, and the communication control part 12 uses the buffer so as to resume data transmission/reception.
ATSUMI NOBORU
YAMAGUCHI HIROYO
FUJITSU LTD