Marl is a high-performance, hybrid thread/fiber task scheduler library written in C++11. It provides a flexible and fluent API for scheduling asynchronous tasks across a configurable number of worker threads, while using fibers (cooperative lightweight threads) to allow tasks to block and yield without stalling hardware threads. The library includes a rich set of synchronization primitives (Event, WaitGroup, Ticket, ConditionVariable, mutex, and DAG for declarative task graphs). It emphasizes safe capture-by-value semantics for primitives to avoid dangling references. The implementation is platform-agnostic with hand-optimized assembly fiber context switching for x86/x64, ARM, RISC-V, LoongArch, MIPS64, and PowerPC64, plus Windows fibers and Emscripten support. The project includes extensive unit tests and benchmarks, a pluggable memory allocator interface, and a tracked allocator for debugging. It is designed as a library to be embedded into larger C++ applications that require fine-grained concurrency control. The codebase demonstrates strong engineering craftsmanship: clean separation of concerns, excellent use of C++ features, Thread Safety Analysis annotations, and thorough testing. Key reusable components include the custom containers (small-buffer optimized vector and efficient list), the pool abstraction (bounded and unbounded), and the flexible allocator framework.
Tina is a header-only library providing lightweight user-space threading through coroutines and fibers, along with a fiber-based job system for task scheduling. The core library (tina.h) implements symmetric and asymmetric coroutine APIs with platform-specific assembly for context switching. Tina Jobs (tina_jobs.h) builds on this to create a job scheduler featuring work-stealing via queue chaining, memory pooling, and fiber-based job execution to avoid OS thread overhead. The repository includes examples (e.g., Mandelbrot renderer using Sokol graphics) and tests demonstrating usage, but the project has migrated to Codeberg due to philosophical opposition to AI training, indicating the GitHub repository is no longer actively maintained. While the Sokol dependencies in extras are third-party, the Tina core showcases strong craftsmanship in low-level concurrency primitives.