ceph/src/boost/libs/fiber/performance/fiber/skynet_stealing_async.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 <queue>
  18 #include <iostream>
  19 #include <memory>
  20 #include <mutex>
  21 #include <numeric>
  22 #include <random>
  23 #include <sstream>
  24 #include <vector>
  25
  26 #include <boost/fiber/all.hpp>
  27 #include <boost/predef.h>
  28
  29 #include "barrier.hpp"
  30
  31 using clock_type = std::chrono::steady_clock;
  32 using duration_type = clock_type::duration;
  33 using time_point_type = clock_type::time_point;
  34 using channel_type = boost::fibers::buffered_channel< std::uint64_t >;
  35 using allocator_type = boost::fibers::fixedsize_stack;
  36 using lock_type = std::unique_lock< std::mutex >;
  37
  38 static bool done = false;
  39 static std::mutex mtx{};
  40 static boost::fibers::condition_variable_any cnd{};
  41
  42 // microbenchmark
  43 std::uint64_t skynet(allocator_type& salloc, std::uint64_t num, std::uint64_t size, std::uint64_t div) {
  44     if ( size != 1){
  45         size /= div;
  46
  47         std::vector<boost::fibers::future<std::uint64_t> > results;
  48         results.reserve( div);
  49
  50         for ( std::uint64_t i = 0; i != div; ++i) {
  51             std::uint64_t sub_num = num + i * size;
  52             results.emplace_back(boost::fibers::async(
  53                   boost::fibers::launch::dispatch
  54                 , std::allocator_arg, salloc
  55                 , skynet
  56                 , std::ref( salloc), sub_num, size, div));
  57         }
  58
  59         std::uint64_t sum = 0;
  60         for ( auto& f : results)
  61             sum += f.get();
  62
  63         return sum;
  64     }
  65
  66     return num;
  67 }
  68
  69 void thread( std::uint32_t thread_count) {
  70     // thread registers itself at work-stealing scheduler
  71     boost::fibers::use_scheduling_algorithm< boost::fibers::algo::work_stealing >( thread_count);
  72     lock_type lk( mtx);
  73     cnd.wait( lk, [](){ return done; });
  74     BOOST_ASSERT( done);
  75 }
  76
  77 int main() {
  78     try {
  79         // count of logical ids
  80         std::uint32_t thread_count = std::thread::hardware_concurrency();
  81         std::size_t size{ 1000000 };
  82         std::size_t div{ 10 };
  83         allocator_type salloc{ 2*allocator_type::traits_type::page_size() };
  84         std::uint64_t result{ 0 };
  85         channel_type rc{ 2 };
  86         std::vector< std::thread > threads;
  87         for ( std::uint32_t i = 1 /* count main-thread */; i < thread_count; ++i) {
  88             // spawn thread
  89             threads.emplace_back( thread, thread_count);
  90         }
  91         // main-thread registers itself at work-stealing scheduler
  92         boost::fibers::use_scheduling_algorithm< boost::fibers::algo::work_stealing >( thread_count);
  93         time_point_type start{ clock_type::now() };
  94         result = skynet( salloc, 0, size, div);
  95         if ( 499999500000 != result) {
  96             throw std::runtime_error("invalid result");
  97         }
  98         auto duration = clock_type::now() - start;
  99         lock_type lk( mtx);
 100         done = true;
 101         lk.unlock();
 102         cnd.notify_all();
 103         for ( std::thread & t : threads) {
 104             t.join();
 105         }
 106         std::cout << "duration: " << duration.count() / 1000000 << " ms" << std::endl;
 107         return EXIT_SUCCESS;
 108     } catch ( std::exception const& e) {
 109         std::cerr << "exception: " << e.what() << std::endl;
 110     } catch (...) {
 111         std::cerr << "unhandled exception" << std::endl;
 112     }
 113         return EXIT_FAILURE;
 114 }