C语言 如何使用 gettimeofday() 或与 Visual Studio C++ 2008 等效的东西？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/2494356/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
how to use gettimeofday() or something equivalent with Visual Studio C++ 2008?
提问by make
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:
有人可以帮我在 Windows XP 上的 Visual Studio C++ 2008 中使用 gettimeofday() 函数吗？这是我在网上某处找到的代码：
#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?
去年当我用 VC++6 测试这段代码时，它运行良好。但是现在当我使用 VC++ 2008 时，出现异常处理错误。那么有没有关于如何使用 gettimeofday 或等效的东西的想法？
Thanks for your reply and any help would be very appreciated:
感谢您的回复，任何帮助将不胜感激：
回答by Neokoder
In UNIX the use of the timezone struct is obsolete.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.htmBut 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.
在 UNIX 中，时区结构的使用已过时。我不知道你为什么使用它。请参阅http://linux.about.com/od/commands/l/blcmdl2_gettime.htm但如果您想使用此结构来了解与本地时间的 GMT(UTC) 差异，它将是下一个：tz_minuteswest 是真正的差异从格林威治标准时间（UTC）开始，以分钟为单位，tz_dsttime 是一个标志，指示现在是否正在使用日光。
Your example with some changes works fine in Visual C++ 2008 Express:
您的一些更改示例在 Visual C++ 2008 Express 中运行良好：
#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;
}
回答by Philm
Simple stopwatch in seconds
秒表简单秒表
FWIW: This is a similar one as that of Kate, but I just wanted to mention it, ifsomeone 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.
FWIW：这与 Kate 的相似，但我只想提一下，如果有人在 C++ 中寻找最简单的秒表（计数秒）。没什么大不了的，我知道。它只有 1 秒的分辨率，因此如果您想计算微秒，请继续其他示例。
double seconds=0;
time_t timer1, timer2;
time(&timer1); /* get current time */
...
time(&timer2); /* get current time later */
seconds = difftime(timer2,timer1);
回答by Kate Gregory
There are a few different types to represent a time. Here's some code I used recently:
有几种不同的类型来表示时间。这是我最近使用的一些代码：
time_t now;
tm* local;
time(&now);
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.
然后我继续从local.
Kate
凯特
回答by Areeha
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);
在我的情况下，它的工作方式如下：因为我想找到平均运行时间，我使用：首先包含在程序的开头，然后：初始化样本=100（例如）；
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
