ceph/src/boost/libs/smart_ptr/test/sp_atomic_mt2_test.cpp

   1
   2 // Copyright (c) 2008 Peter Dimov
   3 //
   4 // Distributed under the Boost Software License, Version 1.0.
   5 // See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt
   7
   8 #include <boost/config.hpp>
   9
  10 #include <boost/shared_ptr.hpp>
  11 #include <boost/bind.hpp>
  12
  13 #include <boost/thread/shared_mutex.hpp>
  14 #include <boost/thread/locks.hpp>
  15
  16 #include <boost/detail/lightweight_mutex.hpp>
  17 #include <boost/detail/lightweight_thread.hpp>
  18
  19 #include <vector>
  20 #include <numeric>
  21 #include <cstdio>
  22 #include <cstdlib>
  23 #include <cstddef>
  24 #include <ctime>
  25
  26 //
  27
  28 static void next_value( unsigned & v )
  29 {
  30     v = v % 2? 3 * v + 1: v / 2;
  31 }
  32
  33 struct X
  34 {
  35     std::vector<unsigned> v_;
  36
  37     explicit X( std::size_t n ): v_( n )
  38     {
  39         for( std::size_t i = 0; i < n; ++i )
  40         {
  41             v_[ i ] = i;
  42         }
  43     }
  44
  45     unsigned get() const
  46     {
  47         return std::accumulate( v_.begin(), v_.end(), 0 );
  48     }
  49
  50     void set()
  51     {
  52         std::for_each( v_.begin(), v_.end(), next_value );
  53     }
  54 };
  55
  56 static boost::shared_ptr<X> ps;
  57
  58 static boost::detail::lightweight_mutex lm;
  59 static boost::shared_mutex rw;
  60
  61 enum prim_type
  62 {
  63     pt_mutex,
  64     pt_rwlock,
  65     pt_atomics
  66 };
  67
  68 int read_access( prim_type pt )
  69 {
  70     switch( pt )
  71     {
  72     case pt_mutex:
  73         {
  74             boost::detail::lightweight_mutex::scoped_lock lock( lm );
  75             return ps->get();
  76         }
  77
  78     case pt_rwlock:
  79         {
  80             boost::shared_lock<boost::shared_mutex> lock( rw );
  81             return ps->get();
  82         }
  83
  84     case pt_atomics:
  85         {
  86             boost::shared_ptr<X> p2 = boost::atomic_load( &ps );
  87             return p2->get();
  88         }
  89     }
  90 }
  91
  92 void write_access( prim_type pt )
  93 {
  94     switch( pt )
  95     {
  96     case pt_mutex:
  97         {
  98             boost::detail::lightweight_mutex::scoped_lock lock( lm );
  99             ps->set();
 100         }
 101         break;
 102
 103     case pt_rwlock:
 104         {
 105             boost::unique_lock<boost::shared_mutex> lock( rw );
 106             ps->set();
 107         }
 108         break;
 109
 110     case pt_atomics:
 111         {
 112             boost::shared_ptr<X> p1 = boost::atomic_load( &ps );
 113
 114             for( ;; )
 115             {
 116                 boost::shared_ptr<X> p2( new X( *p1 ) );
 117                 p2->set();
 118
 119                 if( boost::atomic_compare_exchange( &ps, &p1, p2 ) ) break;
 120             }
 121         }
 122         break;
 123     }
 124 }
 125
 126 void worker( int k, prim_type pt, int n, int r )
 127 {
 128     ++r;
 129
 130     unsigned s = 0, nr = 0, nw = 0;
 131
 132     for( int i = 0; i < n; ++i )
 133     {
 134         if( i % r )
 135         {
 136             s += read_access( pt );
 137             ++nr;
 138         }
 139         else
 140         {
 141             write_access( pt );
 142             ++s;
 143             ++nw;
 144         }
 145     }
 146
 147     printf( "Worker %2d: %u:%u, %10u\n", k, nr, nw, s );
 148 }
 149
 150 #if defined( BOOST_HAS_PTHREADS )
 151   char const * thmodel = "POSIX";
 152 #else
 153   char const * thmodel = "Windows";
 154 #endif
 155
 156 char const * pt_to_string( prim_type pt )
 157 {
 158     switch( pt )
 159     {
 160     case pt_mutex:
 161
 162         return "mutex";
 163
 164     case pt_rwlock:
 165
 166         return "rwlock";
 167
 168     case pt_atomics:
 169
 170         return "atomics";
 171     }
 172 }
 173
 174 static void handle_pt_option( std::string const & opt, prim_type & pt, prim_type pt2 )
 175 {
 176     if( opt == pt_to_string( pt2 ) )
 177     {
 178         pt = pt2;
 179     }
 180 }
 181
 182 static void handle_int_option( std::string const & opt, std::string const & prefix, int & k, int kmin, int kmax )
 183 {
 184     if( opt.substr( 0, prefix.size() ) == prefix )
 185     {
 186         int v = atoi( opt.substr( prefix.size() ).c_str() );
 187
 188         if( v >= kmin && v <= kmax )
 189         {
 190             k = v;
 191         }
 192     }
 193 }
 194
 195 int main( int ac, char const * av[] )
 196 {
 197     using namespace std; // printf, clock_t, clock
 198
 199     int m = 4;          // threads
 200     int n = 10000;      // vector size
 201     int k = 1000000;    // iterations
 202     int r = 100;        // read/write ratio, r:1
 203
 204     prim_type pt = pt_atomics;
 205
 206     for( int i = 1; i < ac; ++i )
 207     {
 208         handle_pt_option( av[i], pt, pt_mutex );
 209         handle_pt_option( av[i], pt, pt_rwlock );
 210         handle_pt_option( av[i], pt, pt_atomics );
 211
 212         handle_int_option( av[i], "n=", n, 1, INT_MAX );
 213         handle_int_option( av[i], "size=", n, 1, INT_MAX );
 214
 215         handle_int_option( av[i], "k=", k, 1, INT_MAX );
 216         handle_int_option( av[i], "iterations=", k, 1, INT_MAX );
 217
 218         handle_int_option( av[i], "m=", m, 1, INT_MAX );
 219         handle_int_option( av[i], "threads=", m, 1, INT_MAX );
 220
 221         handle_int_option( av[i], "r=", r, 1, INT_MAX );
 222         handle_int_option( av[i], "ratio=", r, 1, INT_MAX );
 223     }
 224
 225     printf( "%s: threads=%d size=%d iterations=%d ratio=%d %s\n\n", thmodel, m, n, k, r, pt_to_string( pt ) );
 226
 227     ps.reset( new X( n ) );
 228
 229     clock_t t = clock();
 230
 231     std::vector<pthread_t> a( m );
 232
 233     for( int i = 0; i < m; ++i )
 234     {
 235         boost::detail::lw_thread_create( a[ i ], boost::bind( worker, i, pt, k, r ) );
 236     }
 237
 238     for( int j = 0; j < m; ++j )
 239     {
 240         pthread_join( a[ j ], 0 );
 241     }
 242
 243     t = clock() - t;
 244
 245     double ts = static_cast<double>( t ) / CLOCKS_PER_SEC;
 246     printf( "%.3f seconds, %.3f accesses per microsecond.\n", ts, m * k / ts / 1e+6 );
 247 }