Context switching method, device, program, recording medium, and central processing unit

摘要

In an application in which context switching often occurs such as in a real time OS, it is possible to significantly reduce the overhead caused by the context switching. The OS issues a Swap instruction and a context switch starts. The Swap instruction is issued together with a thread (i.e., context) ID to be replaced, to a thread control unit ( 9 ). The thread ID is used to uniquely identify threads stored in a context cache ( 8 ). The thread control unit ( 9 ) saves data from a register file ( 1 ) to the context cache ( 8 ) via a context-dedicated bus ( 12 ) and transmits data of a new thread from the context cache ( 8 ) to the register file ( 1 ). According to the thread ID received, the thread control unit ( 9 ) automatically interchanges the necessary number of data in the register file ( 1 ) and the data in the context cache ( 8 ).