pooled_work_stealing.hpp

Go to the documentation of this file.

// This file is adapted from fiber/algo/work_stealing.hpp of Boost 1.71.0.
//
//          Copyright Oliver Kowalke 2015 / Lennart Braun 2019.
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file BOOST_SOFTWARE_LICENSE_1_0.txt or copy at
//          http://www.boost.org/LICENSE_1_0.txt)
//
 
#ifndef POOLED_WORK_STEALING_H
#define POOLED_WORK_STEALING_H
 
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <cstddef>
#include <cstdint>
#include <mutex>
#include <vector>
 
#include <boost/config.hpp>
#include <boost/intrusive_ptr.hpp>
 
#include <boost/fiber/algo/algorithm.hpp>
#include <boost/fiber/context.hpp>
#include <boost/fiber/detail/config.hpp>
#include <boost/fiber/detail/context_spinlock_queue.hpp>
#include <boost/fiber/detail/context_spmc_queue.hpp>
#include <boost/fiber/scheduler.hpp>
#include <boost/thread/barrier.hpp>
 
// clang-format off
 
struct pool_ctx;
 
class pooled_work_stealing : public boost::fibers::algo::algorithm {
    std::shared_ptr<pool_ctx> pool_ctx_;
 
    std::uint32_t id_;
    std::uint32_t thread_count_;
#ifdef BOOST_FIBERS_USE_SPMC_QUEUE
    boost::fibers::detail::context_spmc_queue rqueue_ {};
#else
    boost::fibers::detail::context_spinlock_queue rqueue_ {};
#endif
    std::mutex mtx_ {};
    std::condition_variable cnd_{};
    bool flag_{false};
    bool suspend_;
 
    static void init_(std::uint32_t, std::vector<boost::intrusive_ptr<pooled_work_stealing>>&);
 
public:
    static std::shared_ptr<pool_ctx> create_pool_ctx(std::uint32_t, bool = false);
    pooled_work_stealing(std::shared_ptr<pool_ctx>);
    ~pooled_work_stealing();
 
    pooled_work_stealing(pooled_work_stealing const&) = delete;
    pooled_work_stealing(pooled_work_stealing&&) = delete;
 
    pooled_work_stealing& operator=(pooled_work_stealing const&) = delete;
    pooled_work_stealing& operator=(pooled_work_stealing&&) = delete;
 
    virtual void awakened(boost::fibers::context*) noexcept;
 
    virtual boost::fibers::context* pick_next() noexcept;
 
    virtual boost::fibers::context* steal() noexcept {
        return rqueue_.steal();
    }
 
    virtual bool has_ready_fibers() const noexcept {
        return !rqueue_.empty();
    }
 
    virtual void suspend_until(std::chrono::steady_clock::time_point const&) noexcept;
 
    virtual void notify() noexcept;
};
 
// clang-format on
 
#endif  // POOLED_WORK_STEALING_H