REACTOS: SYSTEMS ENGINEERING RESTRUCTURING OF THE WINDOWS NT KERNEL DESIGN AND THE SUBSYSTEMS

ABSTRACT Modern multi-core and multi-socket processor architectures scale primarily through massive increases in core density, exposing severe structural bottlenecks in traditional monolithic operating system designs. The classical Windows NT kernel architecture, which the ReactOS project faithfully reconstructs in C, relies on global spinlocks, rigid interrupt levels and an unsegmented Ring 0 address space. Under high Symmetric Multiprocessing (SMP) loads, these legacy paradigms induce severe lock contention, cache-line bouncing, and vulnerability to system-wide crashes caused by faulty third-party device drivers. This research paper presents a comprehensive systems-engineering restructuring of the ReactOS kernel core and its primary subsystems. By strictly preserving the external Windows NT Application Binary Interface (ABI) while replacing internal bottlenecks with decentralized, lock-free algorithms implemented in no_std Rust, the architecture bridges backward compatibility with modern high-performance computing requirements. Key innovations include: (1) a lock-free Page Frame Number (PFN) database driven by 64-bit atomic Compare-And-Swap (CAS) state mutations and first-order Markov predictive paging.(2) a cybernetic Cache Manager governed by closed-loop feedback control to dynamically compute I/O backpressure and prevent resource exhaustion.(3) an asynchronous, ring-buffer-based I/O subsystem (io_uring-inspired) paired with hardware-assisted Software-Defined Sandboxing (SDS) utilizing CR3/PCID/ASID permutation and Page Attribute Tables (PAT) to isolate and transparently recover crashing drivers in Ring 0 and (4) decentralized Local Ready Queues (LRQ) featuring NUMA-aware, exponential back-off work-stealing and lock-free Deferred Procedure Call (DPC) event streams. To guarantee concurrency correctness without runtime bottlenecks, system-wide state transitions are modeled as a discrete Kripke structure, verified against Linear Temporal Logic (LTL) invariants, and collapsed at compile time into an O(1) bitmask lookup table, supported by sub-nanosecond assembly trap fast paths for x86_64 and ARM64. Ultimately, this interdisciplinary synthesis demonstrates linear CPU scalability and industrial fault tolerance, providing a practical architectural blueprint to evolve ReactOS into a production-ready, next-generation operating system. Dipl.Ing. Franz P. Kalchmair (DFPK) The Technical Documentation is licensed under CC-BY-SA-4.0 license, DFPK, 2026 The Source Codes are published under a Dual-License: GPL-2.0-or-later OR (MIT OR Apache-2.0), DFPK, 2026