From 68d39c708f7f773ca95c2d0cbed35fd1dfa093a2 Mon Sep 17 00:00:00 2001
From: Davis King <davis@dlib.net>
Date: Fri, 15 Sep 2017 21:58:03 -0400
Subject: [PATCH] Changed TIME_THIS() to use std::chrono::high_resolution_clock

---
 dlib/time_this.h | 81 ++++++++++++------------------------------------
 1 file changed, 20 insertions(+), 61 deletions(-)

diff --git a/dlib/time_this.h b/dlib/time_this.h
index 2db135062..09755c07e 100644
--- a/dlib/time_this.h
+++ b/dlib/time_this.h
@@ -4,74 +4,33 @@
 #define DLIB_TIME_THIs_
 
 
-#include "platform.h"
+#include <chrono>
 
-
-
-#ifndef WIN32
-
-#include <sys/times.h>
-#include <limits.h>
-#include <unistd.h>
-#include <iostream>
 // ----------------------------------------------------------------------------------------
 
-#define TIME_THIS_TO(_tt_op,_tt_out)                                                        \
-    {                                                                                       \
-        clock_t _tt_start, _tt_end;                                                         \
-        tms _tt_timesbuf;                                                                   \
-        _tt_start = times(&_tt_timesbuf);                                                   \
-        _tt_op;                                                                             \
-        _tt_end = times(&_tt_timesbuf);                                                     \
-        long _tt_ticks = sysconf(_SC_CLK_TCK);                                              \
-        if ((double)(_tt_end-_tt_start)/(double)_tt_ticks < 1)                              \
-        {                                                                                   \
-            _tt_out << "\ntime: "                                                           \
-            << (int)(1000*((double)(_tt_end-_tt_start)/(double)_tt_ticks)) << "ms\n";       \
-        }                                                                                   \
-        else                                                                                \
-        {                                                                                   \
-            _tt_out << "\ntime: "                                                           \
-                      << (double)(_tt_end-_tt_start)/(double)_tt_ticks << "sec\n";          \
-        }                                                                                   \
-    }                                                                                       \
-
+#define TIME_THIS_TO(_tt_op,_tt_out)                                                                            \
+    {                                                                                                           \
+        auto _tt_start = std::chrono::high_resolution_clock::now();                                             \
+        {_tt_op;}                                                                                               \
+        auto _tt_stop = std::chrono::high_resolution_clock::now();                                              \
+        auto _tt_thetime = _tt_stop-_tt_start;                                                                          \
+        using std::chrono::duration_cast;                                                                       \
+        using std::chrono::duration;                                                                            \
+        if (_tt_thetime >= std::chrono::minutes(1))                                                             \
+            _tt_out << "\ntime: " << duration_cast<duration<double>>(_tt_thetime).count() << "min\n";           \
+        else if (_tt_thetime >= std::chrono::seconds(1))                                                        \
+            _tt_out << "\ntime: " << duration_cast<duration<double>>(_tt_thetime).count() << "sec\n";           \
+        else if (_tt_thetime >= std::chrono::milliseconds(1))                                                   \
+            _tt_out << "\ntime: " << duration_cast<duration<double,std::milli>>(_tt_thetime).count() << "ms\n"; \
+        else if (_tt_thetime >= std::chrono::microseconds(1))                                                   \
+            _tt_out << "\ntime: " << duration_cast<duration<double,std::micro>>(_tt_thetime).count() << "us\n"; \
+        else                                                                                                    \
+            _tt_out << "\ntime: " << duration_cast<duration<double,std::nano>>(_tt_thetime).count() << "ns\n";  \
+    }
 
 #define TIME_THIS(_tt_op)  TIME_THIS_TO(_tt_op,std::cout)
 
 // ----------------------------------------------------------------------------------------
 
-
-#endif
-
-#ifdef WIN32
-
-#include "windows_magic.h"
-#include <windows.h>    // for GetTickCount()
-#include <iostream>
-
-// ----------------------------------------------------------------------------------------
-
-#define TIME_THIS_TO(_tt_op,_tt_out)                                                        \
-    {                                                                                       \
-        unsigned long _tt_count = GetTickCount();                                           \
-        _tt_op;                                                                             \
-        _tt_count = GetTickCount() - _tt_count;                                             \
-        if (_tt_count < 1000)                                                               \
-        {                                                                                   \
-            _tt_out << "\ntime: " << _tt_count << "ms\n";                                   \
-        }                                                                                   \
-        else                                                                                \
-        {                                                                                   \
-            _tt_out << "\ntime: " << static_cast<double>(_tt_count)/1000 << "sec\n";        \
-        }                                                                                   \
-    }                                                                                       \
-
-#define TIME_THIS(_tt_op) TIME_THIS_TO(_tt_op,std::cout)
-
-// ----------------------------------------------------------------------------------------
-
-#endif
-
 #endif // DLIB_TIME_THIs_