US Patent 12019774 Exclusive control system and exclusive control method

Each of a plurality of terminals includes a process executor to set on a server an access right to define an exclusion period during which a first terminal can access a specific file while access thereto by a second terminal is restricted, and to execute an updating process to update the exclusion period before the exclusion period lapses; and a determiner to determine access to the specific file as being restricted if within the exclusion period defined by a second terminal, and to determine access to the specific file as being not restricted if outside the exclusion period.