| 1 | |
|---|---|
| 2 | // Copyright Oliver Kowalke 2015. |
| 3 | // Distributed under the Boost Software License, Version 1.0. |
| 4 | // (See accompanying file LICENSE_1_0.txt or copy at |
| 5 | // http://www.boost.org/LICENSE_1_0.txt) |
| 6 | // |
| 7 | |
| 8 | #ifndef BOOST_FIBERS_ALGO_WORK_STEALING_H |
| 9 | #define BOOST_FIBERS_ALGO_WORK_STEALING_H |
| 10 | |
| 11 | #include <atomic> |
| 12 | #include <condition_variable> |
| 13 | #include <chrono> |
| 14 | #include <cstddef> |
| 15 | #include <cstdint> |
| 16 | #include <mutex> |
| 17 | #include <vector> |
| 18 | |
| 19 | #include <boost/config.hpp> |
| 20 | #include <boost/intrusive_ptr.hpp> |
| 21 | |
| 22 | #include <boost/fiber/algo/algorithm.hpp> |
| 23 | #include <boost/fiber/context.hpp> |
| 24 | #include <boost/fiber/detail/config.hpp> |
| 25 | #include <boost/fiber/detail/context_spinlock_queue.hpp> |
| 26 | #include <boost/fiber/detail/context_spmc_queue.hpp> |
| 27 | #include <boost/fiber/scheduler.hpp> |
| 28 | |
| 29 | #ifdef BOOST_HAS_ABI_HEADERS |
| 30 | # include BOOST_ABI_PREFIX |
| 31 | #endif |
| 32 | |
| 33 | namespace boost { |
| 34 | namespace fibers { |
| 35 | namespace algo { |
| 36 | |
| 37 | class BOOST_FIBERS_DECL work_stealing : public algorithm { |
| 38 | private: |
| 39 | static std::atomic< std::uint32_t > counter_; |
| 40 | static std::vector< intrusive_ptr< work_stealing > > schedulers_; |
| 41 | |
| 42 | std::uint32_t id_; |
| 43 | std::uint32_t thread_count_; |
| 44 | #ifdef BOOST_FIBERS_USE_SPMC_QUEUE |
| 45 | detail::context_spmc_queue rqueue_{}; |
| 46 | #else |
| 47 | detail::context_spinlock_queue rqueue_{}; |
| 48 | #endif |
| 49 | std::mutex mtx_{}; |
| 50 | std::condition_variable cnd_{}; |
| 51 | bool flag_{ false }; |
| 52 | bool suspend_; |
| 53 | |
| 54 | static void init_( std::uint32_t, std::vector< intrusive_ptr< work_stealing > > &); |
| 55 | |
| 56 | public: |
| 57 | work_stealing( std::uint32_t, bool = false); |
| 58 | |
| 59 | work_stealing( work_stealing const&) = delete; |
| 60 | work_stealing( work_stealing &&) = delete; |
| 61 | |
| 62 | work_stealing & operator=( work_stealing const&) = delete; |
| 63 | work_stealing & operator=( work_stealing &&) = delete; |
| 64 | |
| 65 | void awakened( context *) noexcept override; |
| 66 | |
| 67 | context * pick_next() noexcept override; |
| 68 | |
| 69 | virtual context * steal() noexcept { |
| 70 | return rqueue_.steal(); |
| 71 | } |
| 72 | |
| 73 | bool has_ready_fibers() const noexcept override { |
| 74 | return ! rqueue_.empty(); |
| 75 | } |
| 76 | |
| 77 | void suspend_until( std::chrono::steady_clock::time_point const&) noexcept override; |
| 78 | |
| 79 | void notify() noexcept override; |
| 80 | }; |
| 81 | |
| 82 | }}} |
| 83 | |
| 84 | #ifdef BOOST_HAS_ABI_HEADERS |
| 85 | # include BOOST_ABI_SUFFIX |
| 86 | #endif |
| 87 | |
| 88 | #endif // BOOST_FIBERS_ALGO_WORK_STEALING_H |
| 89 |