how to use gettimeofday() or something equivalent with Visual Studio C++ 2008?
Solution 1
In UNIX the use of the timezone struct is obsolete. I don't know why you use it. See http://linux.about.com/od/commands/l/blcmdl2_gettime.htm But if you want to use this structure to know about GMT(UTC) diffrence from your local time it will be next: tz_minuteswest is the real diffrence in minutes from GMT(UTC) and a tz_dsttime is a flag indicates whether daylight is now in use.
Your example with some changes works fine in Visual C++ 2008 Express:
#include "stdafx.h"
#include <time.h>
#include <windows.h>
const __int64 DELTA_EPOCH_IN_MICROSECS= 11644473600000000;
/* IN UNIX the use of the timezone struct is obsolete;
I don't know why you use it. See http://linux.about.com/od/commands/l/blcmdl2_gettime.htm
But if you want to use this structure to know about GMT(UTC) diffrence from your local time
it will be next: tz_minuteswest is the real diffrence in minutes from GMT(UTC) and a tz_dsttime is a flag
indicates whether daylight is now in use
*/
struct timezone2
{
__int32 tz_minuteswest; /* minutes W of Greenwich */
bool tz_dsttime; /* type of dst correction */
};
struct timeval2 {
__int32 tv_sec; /* seconds */
__int32 tv_usec; /* microseconds */
};
int gettimeofday(struct timeval2 *tv/*in*/, struct timezone2 *tz/*in*/)
{
FILETIME ft;
__int64 tmpres = 0;
TIME_ZONE_INFORMATION tz_winapi;
int rez=0;
ZeroMemory(&ft,sizeof(ft));
ZeroMemory(&tz_winapi,sizeof(tz_winapi));
GetSystemTimeAsFileTime(&ft);
tmpres = ft.dwHighDateTime;
tmpres <<= 32;
tmpres |= ft.dwLowDateTime;
/*converting file time to unix epoch*/
tmpres /= 10; /*convert into microseconds*/
tmpres -= DELTA_EPOCH_IN_MICROSECS;
tv->tv_sec = (__int32)(tmpres*0.000001);
tv->tv_usec =(tmpres%1000000);
//_tzset(),don't work properly, so we use GetTimeZoneInformation
rez=GetTimeZoneInformation(&tz_winapi);
tz->tz_dsttime=(rez==2)?true:false;
tz->tz_minuteswest = tz_winapi.Bias + ((rez==2)?tz_winapi.DaylightBias:0);
return 0;
}
int _tmain(int argc, _TCHAR* argv[])
{
struct timeval2 tv;
struct timezone2 tz;
struct tm *tm1;
time_t time1;
ZeroMemory(&tv,sizeof(tv));
ZeroMemory(&tz,sizeof(tz));
gettimeofday(&tv, &tz); // call gettimeofday()
time1=tv.tv_sec;
tm1 = localtime(&time1);
FILE *f;
f=fopen("rez.txt","w");
fprintf(f,"%04d.%02d.%02d %02d:%02d:%02d\n",1900+tm1->tm_year,1+tm1->tm_mon,tm1->tm_mday,tm1->tm_hour,tm1->tm_min,tm1->tm_sec);
fprintf(f,"Diffrence between GMT(UTC) and local time=%d %s\n",tz.tz_minuteswest,"minutes");
fprintf(f,"Is Daylight now=%s\n",tz.tz_dsttime?"Yes":"No");
fclose(f);
return 0;
}
Solution 2
Simple stopwatch in seconds
FWIW: This is a similar one as that of Kate, but I just wanted to mention it, if someone is looking for the most simple stopwatch in C++ (counting seconds). Not a big deal, I know. It has only resolution of 1 sec, so if you want to cound microsecs, go on with the other examples.
double seconds=0;
time_t timer1, timer2;
time(&timer1); /* get current time */
...
time(&timer2); /* get current time later */
seconds = difftime(timer2,timer1);
Solution 3
There are a few different types to represent a time. Here's some code I used recently:
time_t now;
time(&now);
tm* local = localtime(&now);
I then went on to build a string from pieces of local
, but you could do what you wanted at this point.
Solution 4
In my case it worked as following: Since I wanted to find the average running time, i used: First include in the beginning of the program, then: initialize samples=100 (for example);
time_t t_start,t_end;
time(&t_start); //get the current time
//program that needs to be timed
time(&t_end); //get the time at the end of execution of the program
seconds = (difftime(t_start,t_end))/samples;//calculate the difference
make
Thanks to everyone who shared and share his/her idears with me ...
Updated on April 29, 2021Comments
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make almost 3 years
Could someone please help me to use gettimeofday() function with Visual Studio C++ 2008 on Windows XP? here is a code that I found somewhere on the net:
#include < time.h > #include <windows.h> #if defined(_MSC_VER) || defined(_MSC_EXTENSIONS) #define DELTA_EPOCH_IN_MICROSECS 11644473600000000Ui64 #else #define DELTA_EPOCH_IN_MICROSECS 11644473600000000ULL #endif struct timezone { int tz_minuteswest; /* minutes W of Greenwich */ int tz_dsttime; /* type of dst correction */ }; int gettimeofday(struct timeval *tv, struct timezone *tz) { FILETIME ft; unsigned __int64 tmpres = 0; static int tzflag; if (NULL != tv) { GetSystemTimeAsFileTime(&ft); tmpres |= ft.dwHighDateTime; tmpres <<= 32; tmpres |= ft.dwLowDateTime; /*converting file time to unix epoch*/ tmpres -= DELTA_EPOCH_IN_MICROSECS; tmpres /= 10; /*convert into microseconds*/ tv->tv_sec = (long)(tmpres / 1000000UL); tv->tv_usec = (long)(tmpres % 1000000UL); } if (NULL != tz) { if (!tzflag) { _tzset(); tzflag++; } tz->tz_minuteswest = _timezone / 60; tz->tz_dsttime = _daylight; } return 0; } ... // call gettimeofday() gettimeofday(&tv, &tz); tm = localtime(&tv.tv_sec);
Last year when I tested this code with VC++6, it worked fine. But now as I use VC++ 2008, I am getting error of exception handling. So is there any idea on how to use gettimeofday or something equivalent?
Thanks for your reply and any help would be very appreciated: