Listing 9 Extract from counter_resolution.cpp

/* /////////////////////////////////////////////////////////////
 * ...
 *
 * Extract from counter_resolution.cpp
 *
 * Copyright (C) 2002, Synesis Software Pty Ltd.
 * (Licensed under the Synesis Software Standard Source License:
 *  http://www.synesis.com.au/licenses/ssssl.html)
 *
 * ...
 * ////////////////////////////////////////////////////////// */

#include <stdio.h>

#define _WINSTL_NO_NAMESPACES

#include <winstl.h>
#include <winstl_tick_counter.h>
#include <winstl_multimedia_counter.h>
#include <winstl_systemtime_counter.h>
#include <winstl_highperformance_counter.h>
#include <winstl_threadtimes_counter.h>
#include <winstl_processtimes_counter.h>
#include <winstl_performance_counter.h>

#include <stlsoft_limit_traits.h>

/* ////////////////////////////////////////////////////////////////////// */

const int   C_ITERATIONS    =   1000000;

/* ////////////////////////////////////////////////////////////////////// */

template <ws_typename_param_k C>
inline ws_typename_type_k C::interval_type test_resolution(C &counter)
{
  typedef ws_typename_type_k C::interval_type interval_type;

  interval_type   min_inc = stlsoft::limit_traits<interval_type>::maximum();

  for(volatile int i = 0; i < C_ITERATIONS; ++i)
  {
    counter.start();

    // Execute a short inner loop, capping at 2048 repeats
    for(volatile int j = 0; j < (i & 0x7ff); ++j)
    {}

    counter.stop();

    interval_type   interval = counter.get_microseconds();

    if( interval != 0 &&
        interval < min_inc)
    {
      min_inc = interval;
    }
  }

  return min_inc;
}

int main(int /* argc */, char* /* argv */[])
{

#if defined(_STLSOFT_COMPILER_IS_BORLAND) || \
    defined(_STLSOFT_COMPILER_IS_INTEL) || \
    defined(_STLSOFT_COMPILER_IS_MSVC)    
 #define _counter_test_fmt	"%I64d"
#else
 #define _counter_test_fmt	"%lld"
#endif /* compiler */

#define _test_counter(_x)   \
  do \
  { \
    _x x; \
   \
    printf( #_x ": " _counter_test_fmt "us\n", \
            test_resolution(x)); \
  } \
  while(0)

  _test_counter(tick_counter);
  _test_counter(multimedia_counter);
  _test_counter(systemtime_counter);
  _test_counter(highperformance_counter);
  _test_counter(threadtimes_counter);
  _test_counter(processtimes_counter);
  _test_counter(performance_counter);

  return 0;
}