Abstract: In a multiprocessor system, a table is created for each multitask job in the main memory. The table contains a first memory field for storing a task count value "m", second memory fields respectively identified by successive task count values for storing data respectively indicating the execution start times of "m" simultaneously executed tasks, and third memory fields respectively identified by successive task count values for storing the run times of "m" or more simultaneously executed tasks. In response to the roll-in of a given task, the task count value is incremented by 1, and real time data indicated by a system timer is stored into the second memory field identified by the task count value, allowing the selected task to be processed. At the end of the processing of any task, a difference is derived between real time data indicated by the system timer and an execution start time stored in the second memory field identified by the task count value.

Abstract: In a multiprocessor system, a communication register is partitioned into groups of word storage locations and one of the groups is further partitioned into subgroups associated respectively with the processors. An access controller accesses any groups of the communication register when a system program is being processed and accesses one of the subgroup when a user program is being processed. A write controller is responsive to a test & set instruction of first occurrence from a common bus for assembling a lock work with a data word, a control field and a counter field containing a variable count. The control field of the lock word is set to a first binary state when it is assembled and reset to a second binary state when deassembled. In response to a load instruction from the common bus, either the data word from the bus or lock word is stored into a specified storage area of a communication register.