| 摘要 |
PURPOSE:To smoothly process the conflict for occupation of shared resources by keeping the occupation request of a high-level task process waiting until the temporary release enable timing in case said occupation request of the high-level process is produced while a low-level task process is occupying the resources. CONSTITUTION:A group 6 of processes having preference levels respectively and conflicts with the shared resources 7 calls three procedures for occupation of the resources 7. In these procedures a flag 1 and a reservation flag 2 are utilized for each preference level to perform the control of conflict. A resources occupation request procedure 3 waits until all flags 1 can be turned on and therefore can turn on the flag 2. A resources occupation release procedure 4 executes the procedure 3 and then only the processing where all flags 1 are turned on to successively turn off the flags 1. Then the flags 1 can be turned on by another processing via the procedure 3. In a resources occupation process a resources occupation continuation check procedure 5 is carried out as necessary and the occupation processing is continued a resources continuation enable state is decided. While the processing is impossible with resources as long as long as the resources are not occupied again by the procedure 3 when a resources continuation unable state is decided. Thus the processing of a high level has preference. |
