March 2003
Intermediate to advanced
912 pages
27h 17m
English
Assume that a concurrent program has been developed in a modular fashion. We assume that each shared data abstraction is implemented as an abstract data type, as shown in Figure 20.1, and a data object is locked for exclusive use while any of its operations is invoked. Section 12.2 showed how this might be implemented for a single operation.

The problems of uncontrolled concurrent invocation of composite operations, discussed already in Part III, are relevant to this model. Assume in Figure 20.1 that objects A and B are operated ...