PURPOSE: To ensure further higher system using efficiency and performance by synchronizing the execution of the elements of threads in a process.

CONSTITUTION: Before the execution of a thread, whether or not all elements related with the execution are prepared in a local cache related with the thread is decided. When they are all prepared, the execution is started, and otherwise, a pertinent resource is fetched from a main storage, and stored in a local cache 90 before the execution is started. In this case, there is possibility that while one instruction in the thread is executed, the instruction requests data. When such phenomenon occurs, whether or not the requested data are available must be judged. When the data are available, the result of the execution of the instruction is stored, and the execution of the thread is continued, and otherwise, the execution of the thread is interrupted, and the execution of another thread is started. The thread related with the interruption is stored in a special memory, and the arrival of the insufficient data being the cause of the interruption is waited.