6.7

1 files changed, 17 insertions, 24 deletions

diff --git a/zen/tick_count.h b/zen/tick_count.h
index 893d8e80..cb15fe20 100644
--- a/zen/tick_count.h
+++ b/zen/tick_count.h
@@ -10,6 +10,7 @@
 #include <cstdint>
 #include "type_traits.h"
 #include "basic_math.h"
+
 #ifdef ZEN_WIN
 #include "win.h" //includes "windows.h"
 
@@ -19,31 +20,20 @@
 #elif defined ZEN_MAC
 #include <mach/mach_time.h>
 #endif
-//#include <algorithm>
-//#include "assert_static.h"
-//#include <cmath>
 //template <class T> inline
 //T dist(T a, T b)
 //{
 //    return a > b ? a - b : b - a;
 //}
 
-
-
 namespace zen
 {
 //a portable "GetTickCount()" using "wall time equivalent" - e.g. no jumps due to ntp time corrections
 class TickVal;
-std::int64_t dist(const TickVal& lhs, const TickVal& rhs); //use absolute difference for paranoid security: even QueryPerformanceCounter "wraps-around" at *some* time
-
-std::int64_t ticksPerSec(); //return 0 on error
-TickVal getTicks();         //return invalid value on error: !TickVal::isValid()
-
-
-
-
-
+int64_t dist(const TickVal& lhs, const TickVal& rhs); //use absolute difference for paranoid security: even QueryPerformanceCounter "wraps-around" at *some* time
 
+int64_t ticksPerSec(); //return 0 on error
+TickVal getTicks();    //return invalid value on error: !TickVal::isValid()
 
 
 
@@ -69,17 +59,17 @@ public:
     explicit TickVal(const NativeVal& val) : val_(val) {}
 
     inline friend
-    std::int64_t dist(const TickVal& lhs, const TickVal& rhs)
+    int64_t dist(const TickVal& lhs, const TickVal& rhs)
     {
 #ifdef ZEN_WIN
         return numeric::dist(lhs.val_.QuadPart, rhs.val_.QuadPart); //std::abs(a - b) can lead to overflow!
 #elif defined ZEN_LINUX
-        const auto distSec  = numeric::dist(lhs.val_.tv_sec,  rhs.val_.tv_sec);
-        const auto distNsec = numeric::dist(lhs.val_.tv_nsec, rhs.val_.tv_nsec);
-
-        if (distSec > (std::numeric_limits<std::int64_t>::max() - distNsec) / 1000000000) //truncate instead of overflow!
-            return std::numeric_limits<std::int64_t>::max();
-        return distSec * 1000000000 + distNsec;
+//structure timespec documented with members:
+//	time_t  tv_sec    seconds
+//	long    tv_nsec   nanoseconds
+        const int64_t deltaSec  = lhs.val_.tv_sec  - rhs.val_.tv_sec;
+        const int64_t deltaNsec = lhs.val_.tv_nsec - rhs.val_.tv_nsec;
+        return numeric::abs(deltaSec * 1000000000 + deltaNsec);
 #elif defined ZEN_MAC
         return numeric::dist(lhs.val_, rhs.val_);
 #endif
@@ -107,13 +97,13 @@ private:
 
 
 inline
-std::int64_t ticksPerSec() //return 0 on error
+int64_t ticksPerSec() //return 0 on error
 {
 #ifdef ZEN_WIN
     LARGE_INTEGER frequency = {};
     if (!::QueryPerformanceFrequency(&frequency)) //MSDN promises: "The frequency cannot change while the system is running."
         return 0;
-    static_assert(sizeof(std::int64_t) >= sizeof(frequency.QuadPart), "");
+    static_assert(sizeof(int64_t) >= sizeof(frequency.QuadPart), "");
     return frequency.QuadPart;
 
 #elif defined ZEN_LINUX
@@ -123,7 +113,10 @@ std::int64_t ticksPerSec() //return 0 on error
     mach_timebase_info_data_t tbi = {};
     if (::mach_timebase_info(&tbi) != KERN_SUCCESS)
         return 0;
-    return 1000000000 * tbi.denom / tbi.numer;
+//structure mach_timebase_info_data_t documented with members:
+//		uint32_t	numer;
+//		uint32_t	denom;
+    return static_cast<int64_t>(1000000000) * tbi.denom / tbi.numer;
 #endif
 }