ceph/src/boost/libs/fiber/performance/fiber/skynet_shared_join.cpp

   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 // based on https://github.com/atemerev/skynet from Alexander Temerev
   8
   9 #include <algorithm>
  10 #include <cassert>
  11 #include <chrono>
  12 #include <cmath>
  13 #include <condition_variable>
  14 #include <cstddef>
  15 #include <cstdint>
  16 #include <cstdlib>
  17 #include <deque>
  18 #include <iostream>
  19 #include <memory>
  20 #include <mutex>
  21 #include <numeric>
  22 #include <vector>
  23
  24 #include <boost/fiber/all.hpp>
  25 #include <boost/fiber/numa/pin_thread.hpp>
  26 #include <boost/predef.h>
  27
  28 #include "barrier.hpp"
  29
  30 using allocator_type = boost::fibers::fixedsize_stack;
  31 using channel_type = boost::fibers::buffered_channel< std::uint64_t >;
  32 using clock_type = std::chrono::steady_clock;
  33 using duration_type = clock_type::duration;
  34 using lock_type = std::unique_lock< std::mutex >;
  35 using time_point_type = clock_type::time_point;
  36
  37 static bool done = false;
  38 static std::mutex mtx{};
  39 static boost::fibers::condition_variable_any cnd{};
  40
  41 // microbenchmark
  42 void skynet( allocator_type & salloc, channel_type & c, std::size_t num, std::size_t size, std::size_t div) {
  43     if ( 1 == size) {
  44         c.push( num);
  45     } else {
  46         channel_type rc{ 16 };
  47         std::vector< boost::fibers::fiber > fibers;
  48         for ( std::size_t i = 0; i < div; ++i) {
  49             auto sub_num = num + i * size / div;
  50             fibers.emplace_back( boost::fibers::launch::dispatch,
  51                                  std::allocator_arg, salloc,
  52                                  skynet,
  53                                  std::ref( salloc), std::ref( rc), sub_num, size / div, div);
  54         }
  55         for ( auto & f: fibers) {
  56             f.join();
  57         }
  58         std::uint64_t sum{ 0 };
  59         for ( std::size_t i = 0; i < div; ++i) {
  60             sum += rc.value_pop();
  61         }
  62         c.push( sum);
  63     }
  64 }
  65
  66 void thread( unsigned int idx, barrier * b) {
  67     boost::fibers::numa::pin_thread( idx);
  68     boost::fibers::use_scheduling_algorithm< boost::fibers::algo::shared_work >();
  69     b->wait();
  70     lock_type lk( mtx);
  71     cnd.wait( lk, [](){ return done; });
  72     BOOST_ASSERT( done);
  73 }
  74
  75 int main() {
  76     try {
  77         boost::fibers::use_scheduling_algorithm< boost::fibers::algo::shared_work >();
  78         unsigned int n = std::thread::hardware_concurrency();
  79         barrier b( n);
  80         boost::fibers::numa::pin_thread( n - 1);
  81         std::size_t size{ 1000000 };
  82         std::size_t div{ 10 };
  83         std::vector< std::thread > threads;
  84         for ( unsigned int i = 1; i < n; ++i) {
  85             threads.emplace_back( thread, i - 1, & b);
  86         };
  87         allocator_type salloc{ 2*allocator_type::traits_type::page_size() };
  88         std::uint64_t result{ 0 };
  89         channel_type rc{ 2 };
  90         b.wait();
  91         time_point_type start{ clock_type::now() };
  92         skynet( salloc, rc, 0, size, div);
  93         result = rc.value_pop();
  94         if ( 499999500000 != result) {
  95             throw std::runtime_error("invalid result");
  96         }
  97         auto duration = clock_type::now() - start;
  98         lock_type lk( mtx);
  99         done = true;
 100         lk.unlock();
 101         cnd.notify_all();
 102         for ( std::thread & t : threads) {
 103             t.join();
 104         }
 105         std::cout << "duration: " << duration.count() / 1000000 << " ms" << std::endl;
 106         return EXIT_SUCCESS;
 107     } catch ( std::exception const& e) {
 108         std::cerr << "exception: " << e.what() << std::endl;
 109     } catch (...) {
 110         std::cerr << "unhandled exception" << std::endl;
 111     }
 112         return EXIT_FAILURE;
 113 }