Boots – shoes – and leggings
Patent
1989-09-28
1991-05-14
Heckler, Thomas M.
Boots, shoes, and leggings
3642817, 3642316, 3642865, 3642543, 3642463, 3642713, G06F 946
Patent
active
050161660
ABSTRACT:
The system of the present invention provides for the synchronization of access devices connected through the system's memory management unit and is particularly useful in a multi-tasking computer system in which multiple processes access the same device. In the method and apparatus of the present invention, devices that are connected to the system through the MMU are controlled using the page fault mechanism of the MMU and the page fault handler in each segment. Addresses are allocated in the process address space for each process to provide for the addressing of the devices and device queues connected through the MMU, such that one device or one device queue is mapped into one segment of each process address space that will access the device. The "valid bits" associated with each page in a segment are turned on/off by the process or operating system in order to control the device. If the valid bits are off and an attempt is made to access at the address a page fault occurs and the page fault mechanism invokes the page fault handler of the corresponding segment. The page fault mechanism of the MMU and the page fault handler of each segment are then utilized to determine the reason the page fault occurred with respect to a particular process and to perform steps to synchronize access to the device.
REFERENCES:
patent: 4104718 (1978-08-01), Poublan et al.
patent: 4224664 (1980-09-01), Trinchieri
patent: 4394725 (1983-07-01), Bienvenu et al.
patent: 4439830 (1984-03-01), Chueh
patent: 4480304 (1984-10-01), Carr et al.
patent: 4604694 (1986-08-01), Hough
Blasgen et al., "System R: An Architechural Overview", IBM Systems Journal, vol. 20, No. 1 (1981) pp. 41-62.
Astrahan et al., "System R: Relational Approach to Data Base Management" AMC Transactions on Data Base Systems, vol. 1, No. 2 (Jun. 1976), pp. 97-137.
Gray/Watson, "A Shared Segment in Inter-process Communication Facility for VN/370", IBM Report RJ1579 (1975).
Gray, et al., "Granularity of Locks and Degrees of Consistency in a Shared Data Base", Modeling in Data Base Management Systems, Proceedings Of the IFIP Working Conference, (North Holland Publishing Company) (1976), pp. 365-394.
Korth, "Deadlick Freedom Using Edge Locks", ACM Transactions on Database Systems, vol. 7, No. 4, (Dec. 1982), pp. 632-652.
Korth, "Locking Primitives in a Database System", Journal of the Association for Computing Machinery, vol. 30, No. 1 (Jan. 1983), pp. 55-79.
Carrie Susan
Evans Jerald
Loo James Van
Heckler Thomas M.
Sun Microsystems Inc.
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