Add benchmark.cpp and timer related support files

git-svn-id: http://svn.boost.org/svn/boost/sandbox/endian@74296 b8fc166d-592f-0410-95f2-cb63ce0dd405

libs/endian/support/run_timer.cpp

@@ -0,0 +1,132 @@
+//  boost run_timer.cpp  -----------------------------------------------------//
+
+//  Copyright Beman Dawes 1994-2006
+
+//  Distributed under the Boost Software License, Version 1.0.
+//  See http://www.boost.org/LICENSE_1_0.txt)
+
+//  See http://www.boost.org/libs/system for documentation.
+
+//----------------------------------------------------------------------------//
+
+// define BOOST_ENDIAN_SOURCE so that <boost/endian/detail/config.hpp> knows
+// the library is being built (possibly exporting rather than importing code)
+#define BOOST_ENDIAN_SOURCE
+
+#include <boost/endian/support/timer.hpp>
+#include <boost/system/system_error.hpp>
+#include <boost/io/ios_state.hpp>
+#include <boost/throw_exception.hpp>
+#include <boost/cerrno.hpp>
+#include <cstring>
+#include <cassert>
+
+using boost::endian::microsecond_t;
+using boost::endian::times_t;
+using boost::system::error_code;
+
+# if defined(BOOST_WINDOWS_API)
+#   include <windows.h>
+# elif defined(BOOST_POSIX_API)
+#   include <sys/times.h>
+# else
+# error unknown API
+# endif
+
+namespace
+{
+  const char * default_format =
+    " %ws wall, %us user + %ss system = %ts cpu (%p%)\n";
+
+void show_time(const char * format, int places, std::ostream& os,
+    const times_t& times)
+  //  NOTE WELL: Will truncate least-significant digits to LDBL_DIG, which may
+  //  be as low as 10, although will be 15 for many common platforms.
+  {
+    if (times.wall < microsecond_t(0))
+      return;
+    if (places > 6)
+      places = 6;
+    else if (places < 0)
+      places = 0;
+
+    boost::io::ios_flags_saver ifs(os);
+    boost::io::ios_precision_saver ips(os);
+    os.setf(std::ios_base::fixed, std::ios_base::floatfield);
+    os.precision(places);
+
+    const long double sec = 1000000.0L;
+    microsecond_t total = times.system + times.user;
+    long double wall_sec = times.wall / sec;
+    long double total_sec = total / sec;
+
+    for (; *format; ++format)
+    {
+      if (*format != '%' || !*(format+1) || !std::strchr("wustp", *(format+1)))
+        os << *format;
+      else
+      {
+        ++format;
+        switch (*format)
+        {
+        case 'w':
+          os << times.wall / sec;
+          break;
+        case 'u':
+          os << times.user / sec;
+          break;
+        case 's':
+          os << times.system / sec;
+          break;
+        case 't':
+          os << total / sec;
+          break;
+        case 'p':
+          os.precision(1);
+          if (wall_sec > 0.001L && total_sec > 0.001L)
+            os << (total_sec/wall_sec) * 100.0;
+          else
+            os << "n/a";
+          os.precision(places);
+          break;
+        default:
+          assert(0);
+        }
+      }
+    }
+  }
+
+}  // unnamed namespace
+
+namespace boost
+{
+  namespace endian
+  {
+    //  run_timer:: report  --------------------------------------//
+
+    void run_timer::report()
+    {
+      show_time(!m_format
+          ? default_format
+          : m_format,
+        m_places, m_os, this->stop());
+    }
+
+    error_code run_timer::report(error_code& ec)
+    {
+      try
+      {
+        report();
+        ec = error_code();
+      }
+
+      catch (...) // eat any exceptions
+      {
+        ec = error_code(EIO, system::generic_category());
+      }
+
+      return ec;
+    }
+
+  } // namespace endian
+} // namespace boost