CS415 Minithreads Project 6 Overview Adrian Bozdog (Adi) adrianb@cs.cornell.edu

What you have to do Default problem: Optional Problems: Implement Virtual File System Optional Problems: Peer-to-peer file sharing Secret sharing Efficient data collection Application Level Multicast Infrastructure Quorum system Software RAID Sign up for the optional problems until Friday, April 18, 5pm At most 5 groups allowed to work at an optional problem (FCFS policy) One TA supervises an optional problem In the first assignment you should implement a Minithread package at the user-level using a single threaded process. In fact, you should implement a package that can be used by multithreaded programs. The students who will finish the assignment early may try to add preemption to the package.

Virtual File System (1) Uses a block-based interface which simulates a disk (disk.[ch]). Translates block reads/writes to file accesses Provides block-based disk operations There is an NT thread assigned to each disk Provides concurrency control Multiple threads can access the file system An interrupt is generated after each disk operation is completed In the first assignment you should implement a Minithread package at the user-level using a single threaded process. In fact, you should implement a package that can be used by multithreaded programs. The students who will finish the assignment early may try to add preemption to the package.

Virtual File System (2) You need to write a disk interrupt handler Receives a reply from each request Return the result to the minithread that trigger the disk operation (the minithread must be blocked) Disk results refer to block operations, not to user data operations Only one thread is allowed to have disk operations that write data on a file (implement file-level concurrency control) Disk organization: Superblock: Global information about the file system Inodes: Information about the file or directory they represent In the first assignment you should implement a Minithread package at the user-level using a single threaded process. In fact, you should implement a package that can be used by multithreaded programs. The students who will finish the assignment early may try to add preemption to the package.

Optional problem supervisors Peer-to-peer file sharing Mark Robson (mr228) Secret sharing Niranjan Nagarajan (niranjan@cs) Efficient data collection Alex Livshits (as246) Application Level Multicast Infrastructure Adi (adrianb@cs) Quorum system Shafat (shafat@cs) Software RAID Alex Mochtchouk (anm23) In the first assignment you should implement a Minithread package at the user-level using a single threaded process. In fact, you should implement a package that can be used by multithreaded programs. The students who will finish the assignment early may try to add preemption to the package.

Demo presentations Presentations will start May 7 Sign up sheet at 4119 Available at the end of semester (in 2-3 weeks) I will put a message on CMS 15 minutes per group In the first assignment you should implement a Minithread package at the user-level using a single threaded process. In fact, you should implement a package that can be used by multithreaded programs. The students who will finish the assignment early may try to add preemption to the package.