cs-os

Purpose

This skill equips the AI to generate code, explain concepts, and handle tasks related to operating system fundamentals, focusing on processes, threads, fibers, Completely Fair Scheduler (CFS), virtual memory, file systems, inter-process communication (IPC), syscalls, and POSIX standards. Use it to produce accurate, executable code snippets or detailed explanations for OS-related queries.

When to Use

Apply this skill for user queries involving process management (e.g., forking processes), thread synchronization, memory allocation via virtual memory APIs, file system operations like mounting or reading directories, IPC mechanisms such as pipes or sockets, or POSIX-compliant syscalls. Use it in coding scenarios like building a multi-threaded server or debugging memory leaks.

Key Capabilities

• Processes: Handle creation with fork(), termination via waitpid(), and management using exec() family functions with flags like EXEC_ENV.
• Threads/Fibers: Create threads via pthread_create() with attributes like pthread_attr_t, and fibers using user-space libraries like Boost.Context.
• CFS Scheduling: Explain CFS algorithms, including how it uses virtual runtime (vruntime) for fairness; generate code to simulate scheduling with sleep() and getpriority().
• Virtual Memory: Manage mappings with mmap() using flags like MAP_PRIVATE, and unmap with munmap(); handle page faults via mprotect() with PROT_NONE.
• File Systems: Perform operations like open() with O_CREAT|O_EXCL flags, read/write with specific offsets, and directory traversal using opendir()/readdir().
• IPC: Implement pipes with pipe() array, message queues via msgget()/msgsnd(), and sockets with socket(AF_INET, SOCK_STREAM, 0).
• Syscalls: Wrap POSIX syscalls like getpid() or kill() in C code, ensuring error checking with errno.
• POSIX: Ensure compliance by using standards like POSIX.1 for threads and file I/O, with code adhering to real-time extensions.

Usage Patterns

Invoke this skill by prefixing queries with the skill ID, e.g., "cs-os: Write code to fork a process". Always specify context, like "cs-os: Explain CFS with a C simulation". For code generation, request outputs in C or C++ with POSIX headers. Pattern: Query -> AI generates 2-4 line snippets -> AI explains usage. For multi-step tasks, chain with other skills, e.g., first use cs-os for process code, then integrate with a networking skill. Test generated code in a POSIX environment like Linux.