Open File Module
Role in the System
This module defines and implements a suite of routines to manage an open file. The relevant files are openfile.h and openfile.cc. The commands below differ from those in the File System Module in that these routines define operations on individual files, as opposed to the files as a collection:
- open
- close
- read at (a specific location in a file)
- write at (a specific location in a file)
One of the assignments involves implementing an open file table, which is used to streamline file accesses by keeping track of what files are open and how many users are associated with each file. If a request is made to open a file, the system first checks to see if an entry has been placed in the table. With each call to close the file, the system checks to see how many more copies of the file are still being requested. The last process to close the file removes its entry from the open file table.
Uses Relation