From cbc165f22f20ae1cb9c97fe80377512fefa09d80 Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Sun, 24 Jan 2016 21:18:53 +0000
Subject: [PATCH] Use gettimeofday on Linux for the StopWatch.

---
 StopWatch.cpp | 20 ++++++++------------
 StopWatch.h   |  8 ++++----
 2 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/StopWatch.cpp b/StopWatch.cpp
index f3279b4..c2ba6b6 100644
--- a/StopWatch.cpp
+++ b/StopWatch.cpp
@@ -62,24 +62,20 @@ CStopWatch::~CStopWatch()
 
 unsigned long CStopWatch::start()
 {
-	::clock_gettime(CLOCK_MONOTONIC, &m_start);
+	::gettimeofday(&m_start, NULL);
 
-	return m_start.tv_nsec;
+	return m_start.tv_usec;
 }
 
 unsigned int CStopWatch::elapsed()
 {
-	timespec now;
-	::clock_gettime(CLOCK_MONOTONIC, &now);
+	struct timeval now;
+	::gettimeofday(&now, NULL);
 
-	if (m_start.tv_sec == now.tv_sec) {
-		return (now.tv_nsec - m_start.tv_nsec) / 1000000U;
-	} else {
-		long temp = -m_start.tv_nsec / 1000000L;
-		temp += (now.tv_sec - m_start.tv_sec) * 1000L;
-		temp += now.tv_nsec / 1000000L;
-		return temp;
-	}
+	unsigned long long a = m_start.tv_sec * 1000ULL + m_start.tv_usec / 1000ULL;
+	unsigned long long b = now.tv_sec * 1000ULL + now.tv_usec / 1000ULL;
+
+	return (unsigned int)(b - a);
 }
 
 #endif
diff --git a/StopWatch.h b/StopWatch.h
index 4b44cb6..811047e 100644
--- a/StopWatch.h
+++ b/StopWatch.h
@@ -22,7 +22,7 @@
 #if defined(_WIN32) || defined(_WIN64)
 #include <windows.h>
 #else
-#include <ctime>
+#include <sys/time.h>
 #endif
 
 class CStopWatch
@@ -36,10 +36,10 @@ public:
 
 private:
 #if defined(_WIN32) || defined(_WIN64)
-	LARGE_INTEGER m_frequency;
-	LARGE_INTEGER m_start;
+	LARGE_INTEGER  m_frequency;
+	LARGE_INTEGER  m_start;
 #else
-	timespec      m_start;
+	struct timeval m_start;
 #endif
 };