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Writing

The $MT \! B$ associated with an open for writing is the "mutating" counterpart of the $CT \! B$ associated with an open for reading. The command is similar:
open(f,WRITING,$MT \! B$)

When a file, f (as in the above command), is opened for writing and $MT \! B$ is the specified time bound, then the following "rules" apply:

As with the $CT \! B$ the $MT \! B$ should be thought of as a system guarantee and the user or the application may end up doing better--e.g., if available bandwidth is used intelligently!

The correspondence between the modification time bound and the level of optimism or pessimism when opening a file for writing is depicted in Figure 5.2.

Figure 5.2: Modification Time Bound (MTB)
Modification Time Bound (MTB)

The primitive for open for writing is the ANSI-C [21] fopen with an added parameter for specifying the modification time bound:


next up previous contents index
Next: Creating & Deleting Up: The Model Previous: The Consistency Time Bound   Contents   Index

michael@garfield.dk
2000-10-13