[Boost-commit] svn:boost r49923 - in sandbox/chrono: boost/chrono libs/chrono/src libs/chrono/test/chrono_msvc/await_keystroke libs/chrono/test/chrono_msvc/time2_demo

Subject: [Boost-commit] svn:boost r49923 - in sandbox/chrono: boost/chrono libs/chrono/src libs/chrono/test/chrono_msvc/await_keystroke libs/chrono/test/chrono_msvc/time2_demo
From: bdawes_at_[hidden]
Date: 2008-11-24 15:59:54

Author: bemandawes
Date: 2008-11-24 15:59:53 EST (Mon, 24 Nov 2008)
New Revision: 49923
URL: http://svn.boost.org/trac/boost/changeset/49923

Log:
Chrono: add clock now() error_code& argument for error handling. No test cases yet.
Text files modified: 
   sandbox/chrono/boost/chrono/chrono.hpp                                             |    38 +++++++++++++++++++++++++++++++++++---  
   sandbox/chrono/boost/chrono/timer.hpp                                              |     6 ++----                                  
   sandbox/chrono/libs/chrono/src/chrono.cpp                                          |    30 +++++++++++++++++++++---------          
   sandbox/chrono/libs/chrono/test/chrono_msvc/await_keystroke/await_keystroke.vcproj |     4 ++++                                    
   sandbox/chrono/libs/chrono/test/chrono_msvc/time2_demo/time2_demo.vcproj           |     4 ++++                                    
   5 files changed, 66 insertions(+), 16 deletions(-)

Modified: sandbox/chrono/boost/chrono/chrono.hpp
==============================================================================
--- sandbox/chrono/boost/chrono/chrono.hpp	(original)
+++ sandbox/chrono/boost/chrono/chrono.hpp	2008-11-24 15:59:53 EST (Mon, 24 Nov 2008)
@@ -25,6 +25,36 @@
                    Anthony Williams.
 */
 
+/*
+
+TODO:
+
+  * Fully implement error handling, with test cases.
+  * Use boost::throw_exception. (Currently not used because of an issue with Intel 11.0.)
+  * Consider issues raised by Michael Marcin:
+
+    > In the past I've seen QueryPerformanceCounter give incorrect results,
+    > especially with SpeedStep processors on laptops. This was many years ago and
+    > might have been fixed by service packs and drivers.
+    >
+    > Typically you check the results of QPC against GetTickCount to see if the
+    > results are reasonable.
+    > http://support.microsoft.com/kb/274323
+    >
+    > I've also heard of problems with QueryPerformanceCounter in multi-processor
+    > systems.
+    >
+    > I know some people SetThreadAffinityMask to 1 for the current thread call
+    > their QueryPerformance* functions then restore SetThreadAffinityMask. This
+    > seems horrible to me because it forces your program to jump to another
+    > physical processor if it isn't already on cpu0 but they claim it worked well
+    > in practice because they called the timing functions infrequently.
+    >
+    > In the past I have chosen to use timeGetTime with timeBeginPeriod(1) for
+    > high resolution timers to avoid these issues.
+
+*/
+
 #ifndef BOOST_CHRONO_HPP
 #define BOOST_CHRONO_HPP
 
@@ -35,6 +65,7 @@
 #include <boost/chrono/config.hpp>
 #include <boost/ratio.hpp>
 #include <boost/type_traits/common_type.hpp>
+#include <boost/system/error_code.hpp>
 #include <boost/cstdint.hpp>
 #include <boost/type_traits.hpp>
 #include <boost/utility/enable_if.hpp>
@@ -403,7 +434,7 @@
                   || (ratio_divide<Period2, period>::type::den == 1
                     && !treat_as_floating_point<Rep2>::value)
               >::type* = 0)
-#ifdef __GNUC__
+#ifdef        __GNUC__
               // GCC 4.2.4 refused to accept a definition at this point,
               // yet both VC++ 9.0 SP1 and Intel ia32 11.0 accepted the definition
               // without complaint. VC++ 9.0 SP1 refused to accept a later definition,
@@ -877,7 +908,7 @@
       typedef chrono::time_point<system_clock>     time_point;
       static const bool is_monotonic =             false;
 
-      static time_point  now();
+      static time_point  now( system::error_code & ec = system::throws );
 
       static std::time_t to_time_t(const time_point& t);
       static time_point  from_time_t(std::time_t t);
@@ -896,7 +927,7 @@
       typedef chrono::time_point<monotonic_clock>  time_point;
       static const bool is_monotonic =             true;
 
-      static time_point now();
+      static time_point now( system::error_code & ec = system::throws );
   };
 
 //----------------------------------------------------------------------------//
@@ -909,6 +940,7 @@
 
 //----------------------------------------------------------------------------//
 //                 duration constructor implementation                        //
+//              See comment in the class duration synopsis                    //
 //----------------------------------------------------------------------------//
 
 #ifdef __GNUC__

Modified: sandbox/chrono/boost/chrono/timer.hpp
==============================================================================
--- sandbox/chrono/boost/chrono/timer.hpp	(original)
+++ sandbox/chrono/boost/chrono/timer.hpp	2008-11-24 15:59:53 EST (Mon, 24 Nov 2008)
@@ -22,8 +22,6 @@
 //                                 timer                                           //
 //---------------------------------------------------------------------------------//
 
-// TODO: enable commented out ec
-
     template <class Clock>
     class timer
     {
@@ -38,10 +36,10 @@
      ~timer() {}  // never throws
 
       void start( system::error_code & ec = system::throws )
-        { m_start = clock::now(/*ec*/); }
+        { m_start = clock::now( ec ); }
 
       duration elapsed( system::error_code & ec = system::throws )
-        { return clock::now(/*ec*/) - m_start; }
+        { return clock::now( ec ) - m_start; }
 
     private:
       time_point m_start;

Modified: sandbox/chrono/libs/chrono/src/chrono.cpp
==============================================================================
--- sandbox/chrono/libs/chrono/src/chrono.cpp	(original)
+++ sandbox/chrono/libs/chrono/src/chrono.cpp	2008-11-24 15:59:53 EST (Mon, 24 Nov 2008)
@@ -29,18 +29,25 @@
 
 namespace
 {
-  double get_nanosecs_per_tic()
+  double get_nanosecs_per_tic( boost::system::error_code & ec )
   {
     LARGE_INTEGER freq;
     if ( !QueryPerformanceFrequency( &freq ) )
     {
-      throw
-        std::runtime_error( "monotonic_clock: QueryPerformanceFrequency failed" );
+      if ( &ec == &boost::system::throws )
+        throw
+          std::runtime_error( "monotonic_clock: QueryPerformanceFrequency failed" );
+      return -1.0;
     }
+    if ( &ec != &boost::system::throws ) ec.clear();
     return 1000000000.0L / freq.QuadPart;
   }
 
-  double nanosecs_per_tic = get_nanosecs_per_tic();
+  inline double nanosecs_per_tic( boost::system::error_code & ec )
+  {
+    static double ns_per_tic = get_nanosecs_per_tic(ec);
+    return ns_per_tic;
+  }
 }
 
 namespace boost
@@ -48,24 +55,29 @@
 namespace chrono
 {
 
-  monotonic_clock::time_point monotonic_clock::now()
+  monotonic_clock::time_point monotonic_clock::now( system::error_code & ec )
   {
     LARGE_INTEGER pcount;
+    pcount.QuadPart = 1LL;  // just in case nanosecs_per_tic(ec) fails 
     if ( !QueryPerformanceCounter( &pcount ) )
     {
+      if ( &ec == &system::throws )
         throw
           std::runtime_error( "monotonic_clock: QueryPerformanceCounter failed" );
-    }
+      return time_point(duration(
+        static_cast<monotonic_clock::rep>(-1.0) ));
+   }
 
+    if ( &ec != &system::throws ) ec.clear();
     return time_point(duration(
-      static_cast<monotonic_clock::rep>(nanosecs_per_tic * pcount.QuadPart) ));
+      static_cast<monotonic_clock::rep>(nanosecs_per_tic(ec) * pcount.QuadPart) ));
   }
 
-
-  system_clock::time_point system_clock::now()
+  system_clock::time_point system_clock::now( system::error_code & ec )
   {
     FILETIME ft;
     ::GetSystemTimeAsFileTime( &ft );  // never fails
+    if ( &ec != &system::throws ) ec.clear();
     return time_point(duration(
       (static_cast<__int64>( ft.dwHighDateTime ) << 32) | ft.dwLowDateTime));
   }

Modified: sandbox/chrono/libs/chrono/test/chrono_msvc/await_keystroke/await_keystroke.vcproj
==============================================================================
--- sandbox/chrono/libs/chrono/test/chrono_msvc/await_keystroke/await_keystroke.vcproj	(original)
+++ sandbox/chrono/libs/chrono/test/chrono_msvc/await_keystroke/await_keystroke.vcproj	2008-11-24 15:59:53 EST (Mon, 24 Nov 2008)
@@ -176,6 +176,10 @@
                                 RelativePath="..\..\..\src\chrono.cpp"
 				>
                         </File>
+			<File
+				RelativePath="..\..\..\..\system\src\error_code.cpp"
+				>
+			</File>
                 </Filter>
                 <Filter
                         Name="Header Files"

Modified: sandbox/chrono/libs/chrono/test/chrono_msvc/time2_demo/time2_demo.vcproj
==============================================================================
--- sandbox/chrono/libs/chrono/test/chrono_msvc/time2_demo/time2_demo.vcproj	(original)
+++ sandbox/chrono/libs/chrono/test/chrono_msvc/time2_demo/time2_demo.vcproj	2008-11-24 15:59:53 EST (Mon, 24 Nov 2008)
@@ -173,6 +173,10 @@
 				>
                         </File>
                         <File
+				RelativePath="..\..\..\..\system\src\error_code.cpp"
+				>
+			</File>
+			<File
                                 RelativePath="..\..\..\example\time2_demo.cpp"
 				>
                         </File>