| 摘要 |
PURPOSE:To make the assignment and the revervation of input/output devices efficient, by generating queue structures for every level of respective tasks in accordance with their state and ranking tasks in these queue and changing this ranking. CONSTITUTION:Lower-level tasks 2 and 2' consisting of tasks for interpreting user programs, middle-level tasks 3 and 3' which control input/output devices 5 and 5', and a high-level task 1 which controls the state of these low-level and middle-level tasks are controlled by an operating system OS 4. Respective tasks are registered in an execution queue (E.Q) or ready queue (R.Q) for every level, and ranks of execution waiting tasks which are ranked and registered in the R.Q in the FIFO system are changed by a rank changing means. Commands issued to waiting middle-level tasks are registered in a command execution list, and commands issued to executing or execution waiting middle-tasks are registered in a command start list. Consequently, input/output devices are used efficiently. |
