Fix time::now() on windows and simplify implementation

This commit is contained in:
Sebastian Messmer 2018-08-02 23:49:45 -07:00
parent 6f175e0b9b
commit 76969171c7

View File

@ -1,65 +1,21 @@
#include "time.h"
#include <chrono>
#if defined(_MSC_VER)
// Windows
// Implementation taken from https://stackoverflow.com/a/31335254
using std::chrono::system_clock;
using std::chrono::duration_cast;
using std::chrono::seconds;
using std::chrono::nanoseconds;
#include <Windows.h>
constexpr __int64 exp7 = 10000000i64; //1E+7
constexpr __int64 exp9 = 1000000000i64; //1E+9
constexpr __int64 w2ux = 116444736000000000i64; //1.jan1601 to 1.jan1970
namespace cpputils {
namespace time {
struct timespec now() {
__int64 wintime;
GetSystemTimeAsFileTime((FILETIME*)&wintime);
wintime -= w2ux;
struct timespec now() {
auto now = system_clock::now().time_since_epoch();
struct timespec spec;
spec.tv_sec = wintime / exp7;
spec.tv_nsec = wintime % exp7 * 100;
spec.tv_sec = duration_cast<seconds>(now).count();
spec.tv_nsec = duration_cast<nanoseconds>(now).count() % 1000000000;
return spec;
}
}
}
#elif defined(__MACH__) && !defined(CLOCK_REALTIME)
// OSX before 10.12 has no clock_gettime
// Implementation taken from: http://stackoverflow.com/a/9781275/829568
// Caution: The returned value is less precise than the returned value from a linux clock_gettime would be.
#include <sys/time.h>
namespace cpputils {
namespace time {
struct timespec now() {
struct timeval now {};
int rv = gettimeofday(&now, nullptr);
if (rv) {
throw std::runtime_error("gettimeofday failed with " + std::to_string(rv));
}
struct timespec result;
result->tv_sec = now.tv_sec;
result->tv_nsec = now.tv_usec * 1000;
return now;
}
}
}
#else
// Linux or OSX with clock_gettime implementation
namespace cpputils {
namespace time {
struct timespec now() {
struct timespec now{};
clock_gettime(CLOCK_REALTIME, &now);
return now;
}
}
}
#endif