QThread

Header-only C++ thread pool with a safe task queue and future-based results.

Qthread combines a queue + thread pool in a simple, portable, single-header library. It makes parallel execution easy: submit lambdas, functors, or functions, and retrieve results via std::future.

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Features

• Header-only - just drop qthread.hpp into your project.
• Thread pool - manage a fixed number of worker threads.
• Safe Task queue - tasks are stored and processed in FIFO order.
• Future-based results - submit tasks and get back std::future<T>.
• No dependencies - pure C++ standard library.

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Instalation

Just copy the include/qthread.hpp into your codebase.

Usage Example

FIFO Thread Pool

#include "qthread.hpp"
#include <iostream>

int main() {
    auto poo = qthread::make_fifo_pool(4);

    auto f1 = pool.submit([] { return 42; });
    auto f2 = pool.submit([](int a, int b) { return a + b; }, 10, 32);

    std::cout << "f1 = " << f1.get() << "\n";
    std::cout << "f2 = " << f2.get() << "\n";

    pool.wait_for_completion();
}

Priority Thread Pool

#include "qthread.hpp"
#include <iostream>

int main() {
    auto pool = qthread::make_priority_pool(2);

    pool.submit([] { std::cout << "Low priority\n"; }, qthread::Priority::Low);
    pool.submit([] { std::cout << "High priority\n"; }, qthread::Priority::High);
    pool.submit([] { std::cout << "Normal priority\n"; }, qthread::Priority::Normal);

    pool.wait_for_completion();
}

Building and Testing

cmake -S . -B build
cmake --build build
ctest --test-dir build --output-on-failure

Roadmap

Planned features for future versions:

• [x] Task priorities.
• [ ] Task Cancellation
• [ ] Dynamic thread pool resizing
• [ ] Work-stealing scheduler
• [ ] Timeout and deadline support
• [ ] Thread affinity / CPU pinnig
• [ ] metrics and instrumentation

Contributing

Contributions are Welcome!

• Fork the repo and create a new branch
• Add your changes with tests if possible
• Ensure formatting passes clang-format
• Submit a PR