PURPOSE: To prevent a mutual interference between user programs, and to enable a parallel processing of a buffer controlling part by providing the two kinds of locks instead of dividing the buffer. and operating an exclusive control between the user programs by using these locks according to an access request.
CONSTITUTION: The access request to a page from a user programs 101 is exclusively controlled by local locks 205, so that the mutual interference can not be generated. The number of the local locks 205 is larger than that of the simultaneously traveling user programs 101, so that it is not necessary to wait for obtaining the local locks 205. And also, at the time of a reference request, the selection of frames 201 to be reloaded and the update of an LRU (Least Recently Used) chain or the like, are exclusively controlled by global lock 202, a time required for both processings is shorter than that required for reading the page from a file, and it is not necessary to wait for obtaining the global lock 202. Thus, the parallel control of the buffer controlling part can be attained.
HOZAI TAKASHI
KATAOKA RYOJI
