ceph/src/boost/libs/thread/example/perf_shared_mutex.cpp

   1 //  (C) Copyright 2013 Andrey
   2 //  (C) Copyright 2013 Vicente J. Botet Escriba
   3 //
   4 //  Distributed under the Boost Software License, Version 1.0. (See
   5 //  accompanying file LICENSE_1_0.txt or copy at
   6 //  http://www.boost.org/LICENSE_1_0.txt)
   7 //
   8 // This performance test is based on the performance test provided by maxim.yegorushkin
   9 // at https://svn.boost.org/trac/boost/ticket/7422
  10
  11 #define BOOST_THREAD_USES_CHRONO
  12
  13 #include <iostream>
  14 #include <boost/thread/lock_types.hpp>
  15 #include <boost/thread/thread_only.hpp>
  16 #include <boost/chrono/chrono_io.hpp>
  17
  18 #include <boost/thread/shared_mutex.hpp>
  19
  20 using namespace boost;
  21
  22 shared_mutex mtx;
  23 const int cycles = 10000;
  24
  25 void shared()
  26 {
  27   int cycle(0);
  28   while (++cycle < cycles)
  29   {
  30     shared_lock<shared_mutex> lock(mtx);
  31   }
  32 }
  33
  34 void unique()
  35 {
  36   int cycle(0);
  37   while (++cycle < cycles)
  38   {
  39     unique_lock<shared_mutex> lock(mtx);
  40   }
  41 }
  42
  43 int main()
  44 {
  45   boost::chrono::high_resolution_clock::duration best_time(std::numeric_limits<boost::chrono::high_resolution_clock::duration::rep>::max BOOST_PREVENT_MACRO_SUBSTITUTION ());
  46   for (int i =100; i>0; --i) {
  47     boost::chrono::high_resolution_clock clock;
  48     boost::chrono::high_resolution_clock::time_point s1 = clock.now();
  49     thread t0(shared);
  50     thread t1(shared);
  51     thread t2(unique);
  52     //thread t11(shared);
  53     //thread t12(shared);
  54     //thread t13(shared);
  55
  56     t0.join();
  57     t1.join();
  58     t2.join();
  59     //t11.join();
  60 //    t12.join();
  61   //  t13.join();
  62     boost::chrono::high_resolution_clock::time_point f1 = clock.now();
  63     //std::cout << "     Time spent:" << (f1 - s1) << std::endl;
  64     best_time = std::min BOOST_PREVENT_MACRO_SUBSTITUTION (best_time, f1 - s1);
  65
  66   }
  67   std::cout << "Best Time spent:" << best_time << std::endl;
  68   std::cout << "Time spent/cycle:" << best_time/cycles/3 << std::endl;
  69
  70   return 1;
  71 }
  72