xv6_operating_system

CS 333 Introduction to Operating Systems

Course Coordinator: Jesse Chaney

Course Description:

Introduction to the principles of operating systems and concurrent programming. Operating system services, file systems, resource management, synchronization. The concept of a process; process cooperation and interference. Introduction to networks, and protection and security. Examples drawn from one or more modern operating systems. Programming projects, including concurrent programming.

Prerequisites: CS 302

Goals:

• To expose students to the fundamental architectural and algorithmic concepts involved in the design and implementation of modern operating systems. This will include the design and coding of concurrent programs.
• Upon the successful completion of this class, students will be able to:
  • Read technical material that refers to operating system concepts.
  • Write system-level code.
  • Apply synchronization-related concerns when implementing code.
  • Continue on to study advanced operating systems.
  • Describe observed application runtime behavior.

Textbooks:

• Operating Systems: Three Easy Pieces, Remzi Arpaci-Dusseau and Andrea Arpaci Dusseau, 2016
• Xv6: a simple, Unix-like teaching operating system, Russ Cox, 2014

References:

• The C Programming Language, 2nd ed., Kernighan and Ritchie, Prentice Hall, 1998. ISBN 0131103628
• Practical Guide to Linux Commands, Editors, and Shell Programming, A (2nd Edition) ISBN 0131367366

Major Topics:

• Processes
• Inter-process communication
• Concurrent Programming
• Scheduling
• Memory Management
• File Systems
• Synchronization
• Device Management
• Introductions to Protection & Security and to Networking

Problem Analysis:

Students complete a variety of projects that require problem analysis, design, coding, and testing. For example, students might design a shell program based on knowledge of desired shell behavior, or design and add synchronization to a multithreaded code. Specific projects vary for each course offering.

Solution Design:

One or more projects require solution design, for example, changing existing code to remove a race condition.

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Write functions in xv6

• vikalloc_set_min(size_t size): Sets the minimum memory allocation size and returns the current minimum size.

• vikalloc_set_algorithm(vikalloc_fit_algorithm_t algorithm): Configures the memory allocation algorithm and logs the choice in verbose mode.

• vikalloc_set_verbose(uint8_t verbosity): Enables or disables verbose mode for logging messages.

• vikalloc_set_log(FILE *stream): Sets the log stream for message output.

• vikalloc(size_t size): Allocates memory using various allocation algorithms (e.g., FIRST_FIT, BEST_FIT), reusing or creating blocks as needed and handling block splitting.

• coalesce(mem_block_t *curr): Combines adjacent free memory blocks into larger blocks through coalescing.

• vikfree(void *ptr): Frees previously allocated memory blocks, coalescing adjacent free blocks if necessary.

• vikalloc_reset(void): Deallocates all allocated memory, effectively resetting vikalloc.

• vikcalloc(size_t nmemb, size_t size): Allocates memory for arrays, initializing elements to zero.

• vikrealloc(void *ptr, size_t size): Reallocates memory for a previously allocated block, extending it or allocating a new block and copying data.

• vikstrdup(const char *s): Allocates memory for a duplicated string, copying the input string and returning a pointer to the duplicate.