ObservableCollections is a high-performance .NET library providing generic observable collections (ObservableList, ObservableDictionary, ObservableHashSet, ObservableQueue, ObservableStack, ObservableRingBuffer, ObservableFixedSizeRingBuffer) with synchronized views, filters, and writable views. It replaces the non-generic, allocation-heavy .NET ObservableCollection with zero-allocation event args using ref structs and ReadOnlySpan. The library is designed for MVVM architectures in WPF, Blazor, Avalonia, Unity, and WinUI, offering both read-only and writable synchronized views that can be bound via INotifyCollectionChanged. It also provides R3 reactive extensions for Rx-style event observation. The codebase is highly optimized, leveraging modern C# features like ref structs, spans, and custom data structures (e.g., RingBuffer, AlternateIndexList) for minimal allocations and maximum performance.
CIM (Cross-platform Instant Messaging) is a production-grade, modular instant messaging framework built with Java 17, Spring Boot 3.3, and Netty. It provides a complete IM solution including a Netty-based server (cim-server) for handling client connections and message forwarding, a routing server (cim-forward-route) for message routing, user login/offline management, and a client SDK (cim-client-sdk) for building custom clients. The system uses Zookeeper for service discovery, Redis for caching and session management, and optionally MySQL for offline message persistence. It supports group chat, private chat, offline messages, delayed messages, emoji, AI mode, and a built-in command system. The architecture is microservice-oriented with clear separation of concerns, and the codebase demonstrates strong engineering practices including consistent hashing for server selection, a custom ring buffer wheel for delayed tasks, a dynamic HTTP proxy for RPC calls, and a trie-based prefix search. The project includes comprehensive unit and integration tests, Docker support, and CI/CD pipelines.
lockfree is a header-only C++11 library providing lock-free data structures for concurrent programming. It offers both single-producer single-consumer (SPSC) and multi-producer multi-consumer (MPMC) variants of queues, ring buffers, bipartite buffers, and priority queues. The library is designed for use across a wide spectrum of systems from deeply embedded to HPC, featuring no dynamic allocation and optimized for high performance. Architecture-wise, it's organized into spsc/ and mpmc/ namespaces with each data structure having separate header and implementation files, aggregated through lockfree.hpp. The implementation uses atomic operations and clever algorithms to achieve lock-free behavior without mutexes.
This repository is a large collection of bare-metal firmware projects for STM32 microcontrollers (F0, F1, F3, G0, G4 families), authored by Edward V. Emelianov. It contains dozens of independent example and application projects covering USB CDC virtual serial ports, CAN bus gateways, sensor drivers (BMP280, MLX90640, DHT22, DS18B20, etc.), stepper motor control, servo control, LED displays, and more. The code is written in C with direct register access (no HAL) and uses a custom USB stack with ring-buffer-based I/O. Each project is self-contained with its own main.c, hardware initialization, and command parser, typically communicating over USB or UART with a simple text-based protocol. The architecture is monolithic per project: a main loop processes periodic tasks (ADC sampling, sensor reads, CAN message handling) and responds to commands received via USB or UART. Key entry points are the main.c files in each project directory. Data flows involve sensor acquisition (ADC, I2C, SPI), optional processing (median filtering, dew point calculation), and output via USB CDC, CAN, or UART. External dependencies are minimal: only an ARM GCC toolchain and the STM32 CMSIS-like headers provided in the inc/ folder. The repository also includes KiCad PCB designs and gerber files for many projects, indicating a full hardware+software development cycle. While the code is functional and covers a wide range of embedded use cases, it suffers from significant code duplication (ringbuffer.c, usb.c, strfunc.c are copy-pasted across many projects) and lacks a centralized library or build system. Deprecated folders and multiple versions of similar projects (e.g., chronometer_v2, chronometer_v3) add clutter. The repository is best viewed as a personal collection of working examples and prototypes rather than a polished framework. However, several components (ring buffer, string utilities, USB stack) are well-implemented and could be extracted for reuse in other STM32 projects.