Passive serialization in a multitasking environment
In a multiprocessing system having a control program in which data objects are shared among processes, this patent describes a method for serializing references to a data object by the processes so as to prevent invalid references to the data object by any process when an operation requiring exclusive access is performed by another process, comprising the steps of: permitting the processes to reference data objects on a shared access basis without obtaining a shared lock; monitoring a point of execution of the control program which is common to all processes in the system, which occurs regularly in the process' execution and across which no references to any data object can be maintained by any process, except references using locks; establishing a system reference point which occurs after each process in the system has passed the point of execution at least once since the last such system reference point; requesting an operation requiring exclusive access on a selected data object; preventing subsequent references by other processes to the selected data object; waiting until two of the system references points have occurred; and then performing the requested operation.
- Assignee:
- International Business Machines Corp., Armonk, NY
- Patent Number(s):
- US 4809168
- OSTI ID:
- 6384771
- Resource Relation:
- Patent File Date: Filed date 17 Oct 1986
- Country of Publication:
- United States
- Language:
- English
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