zShanCS / zos

a little operating system to learn how it works

Threaded File System

Logical file system that implements paging, multithreading, etc.

Usage

Run each cell on Google Colab

OR

Run locally: python main.py

Settings

• No. of Pages: 10,000
• Page Size: 64 B

Notes

1. If a thread opens a file for modification, the changes it makes will not be saved until it closes the file.
2. Reading a file's contents is already thread safe (point 3 touches this further).
3. A thread cannot read the updated contents of a file until the writer thread has closed the file.
4. A file is locked for modification by a single thread.

Additional Features

• Global File Table that maps that uses filename to index into the threads that have opened the file and the associated file mode.
• Integers are returned by the FileSystem object to indicate failure status.