| 1 | |
|---|---|
| 2 | // Copyright Oliver Kowalke 2013. |
| 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 | #include "boost/fiber/algo/shared_work.hpp" |
| 8 | |
| 9 | #include <boost/assert.hpp> |
| 10 | |
| 11 | #include "boost/fiber/type.hpp" |
| 12 | |
| 13 | #ifdef BOOST_HAS_ABI_HEADERS |
| 14 | # include BOOST_ABI_PREFIX |
| 15 | #endif |
| 16 | |
| 17 | namespace boost { |
| 18 | namespace fibers { |
| 19 | namespace algo { |
| 20 | |
| 21 | //[awakened_ws |
| 22 | void |
| 23 | shared_work::awakened( context * ctx) noexcept { |
| 24 | if ( ctx->is_context( t: type::pinned_context) ) { /*< |
| 25 | recognize when we're passed this thread's main fiber (or an |
| 26 | implicit library helper fiber): never put those on the shared |
| 27 | queue |
| 28 | >*/ |
| 29 | lqueue_.push_back( value&: * ctx); |
| 30 | } else { |
| 31 | ctx->detach(); |
| 32 | std::unique_lock< std::mutex > lk{ rqueue_mtx_ }; /*< |
| 33 | worker fiber, enqueue on shared queue |
| 34 | >*/ |
| 35 | rqueue_.push_back( x: ctx); |
| 36 | } |
| 37 | } |
| 38 | //] |
| 39 | |
| 40 | //[pick_next_ws |
| 41 | context * |
| 42 | shared_work::pick_next() noexcept { |
| 43 | context * ctx = nullptr; |
| 44 | std::unique_lock< std::mutex > lk{ rqueue_mtx_ }; |
| 45 | if ( ! rqueue_.empty() ) { /*< |
| 46 | pop an item from the ready queue |
| 47 | >*/ |
| 48 | ctx = rqueue_.front(); |
| 49 | rqueue_.pop_front(); |
| 50 | lk.unlock(); |
| 51 | BOOST_ASSERT( nullptr != ctx); |
| 52 | context::active()->attach( ctx); /*< |
| 53 | attach context to current scheduler via the active fiber |
| 54 | of this thread |
| 55 | >*/ |
| 56 | } else { |
| 57 | lk.unlock(); |
| 58 | if ( ! lqueue_.empty() ) { /*< |
| 59 | nothing in the ready queue, return main or dispatcher fiber |
| 60 | >*/ |
| 61 | ctx = & lqueue_.front(); |
| 62 | lqueue_.pop_front(); |
| 63 | } |
| 64 | } |
| 65 | return ctx; |
| 66 | } |
| 67 | //] |
| 68 | |
| 69 | void |
| 70 | shared_work::suspend_until( std::chrono::steady_clock::time_point const& time_point) noexcept { |
| 71 | if ( suspend_) { |
| 72 | if ( (std::chrono::steady_clock::time_point::max)() == time_point) { |
| 73 | std::unique_lock< std::mutex > lk{ mtx_ }; |
| 74 | cnd_.wait( lock&: lk, p: [this](){ return flag_; }); |
| 75 | flag_ = false; |
| 76 | } else { |
| 77 | std::unique_lock< std::mutex > lk{ mtx_ }; |
| 78 | cnd_.wait_until( lock&: lk, atime: time_point, p: [this](){ return flag_; }); |
| 79 | flag_ = false; |
| 80 | } |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | void |
| 85 | shared_work::notify() noexcept { |
| 86 | if ( suspend_) { |
| 87 | std::unique_lock< std::mutex > lk{ mtx_ }; |
| 88 | flag_ = true; |
| 89 | lk.unlock(); |
| 90 | cnd_.notify_all(); |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | shared_work::rqueue_type shared_work::rqueue_{}; |
| 95 | std::mutex shared_work::rqueue_mtx_{}; |
| 96 | |
| 97 | }}} |
| 98 | |
| 99 | #ifdef BOOST_HAS_ABI_HEADERS |
| 100 | # include BOOST_ABI_SUFFIX |
| 101 | #endif |
| 102 |