Discuss the different techniques with which a file can be shared among different users.
Several popular techniques with that a file can be shared among various users are:
1. Sequential sharing: In this technique of sharing, a file can be shared through only one program at a time, it is file accesses by P1 and P2 are spaced-out over time. A lock field can be utilized to implement it. Setting and re-setting of the lock at file open and close makes sure that only one program can utilize the file at any time.
2. Concurrent sharing: Some number of programs may share a file concurrently. While this is the case, this is essential to ignore mutual interference among the
m. There are three categories of concurrent sharing:
a. Immutable files: If a file is shared into immutable mode, no one of the sharing programs can modify it. Such mode has the advantage that sharing programs are independent of one more.
b. Single image immutable files: There the changes made by one program are instantly visible to other programs. The Unix file system utilizes this file- sharing mode.
c. Multiple image mutable files: There many programs can concurrently update the shared file. All updating program creates a latest version of the file that is different from the version created through concurrent programs. Such sharing mode can only be utilized in applications where the existence of multiple versions and concurrent updates are meaningful.