时钟() [英] clock()
问题描述
好的,所以我试图确定boost.timer是如何工作的,我尝试了一些
的东西,而且不会。所以我打开标题来查看原因并运行
一些测试来确定发生了什么,这一切都归结为
clock()函数。以下是代码:
#include< iostream>
#include< cstdlib>
int main(void)
{
boost :: timer tmr;
sleep(15);
std: :cout<< std :: clock()<< std :: endl;
返回0;
}
该程序始终输出0。关于clock()的文档说它自从程序启动以来它应该返回时钟滴答,其中15 / b
的第二次睡眠应该是充足的。我不明白。
clock()函数返回
$使用的处理器时间的近似值b $ b程序。
但sleep()函数不使用处理器时间。
> ro**********@gmail.comw 死记硬背:
好的,所以我试图确定boost.timer是如何工作的,我尝试了一下
几个事情,并且它没有。所以我打开标题看看为什么和
运行一些测试来确定发生了什么,这一切都归结为
clock()函数。以下是代码:
#include< iostream>
#include< cstdlib>
int main(无效)
{
boost :: timer tmr;
sleep(15);
std :: cout<< std :: clock()<< std :: endl;
返回0;
}
该程序始终输出0。关于clock()的文档说
它应该在程序启动后返回时钟滴答,其中15/2秒睡眠应该是充足的。我不明白。
#include< ctime>
#include< cstdlib>
#include< iostream>
使用命名空间std;
int main()
{
sleep(10);
cout<< clock()<<结束;
返回0;
}
输出15。
JetSnaiL写道:ro ********** @ gmail.comw 死记硬背:
好的,所以我试图确定boost.timer的工作方式和我尝试一下
几个事情,并且不会。所以我打开标题看看为什么和
运行一些测试来确定发生了什么,这一切都归结为
< blockquote class =post_quotes> clock()函数。以下是代码:
#include< iostream>
#include< cstdlib>
int main(无效)
{
boost :: timer tmr;
sleep(15);
std :: cout<< std :: clock()<< std :: endl;
返回0;
}
该程序始终输出0。关于clock()的文档说
它应该返回自程序启动以来的时钟滴答,这应该是足够的第二次睡眠。我不明白。
#include< ctime>
#include< cstdlib>
#include< iostream>
使用命名空间std;
int main()
{
睡眠(10);
cout<< clock()<< endl;
返回0;
}
输出15。
好吧,我得到0。
Ok, so I am trying to establish how boost.timer works and I try a few
things and afaict it doesn''t. So I open the header to see why and run
some tests to establish what is going on and it all boils down to the
clock() function. Here is the code:
#include <iostream>
#include <cstdlib>
int main(void)
{
boost::timer tmr;
sleep(15);
std::cout << std::clock() << std::endl;
return 0;
}
That program always outputs "0". Documentation on clock() says that it
should return clock ticks since program started, which with the 15
second sleep that should be plenty. I don''t understand.
The clock() function returns an approximation of processor time used by
the program.
but sleep() function not use processor time.
> ro**********@gmail.comwrote:
Ok, so I am trying to establish how boost.timer works and I try a
fewthings and afaict it doesn''t. So I open the header to see why and run some tests to establish what is going on and it all boils down to the clock() function. Here is the code:
#include <iostream>
#include <cstdlib>
int main(void)
{
boost::timer tmr;
sleep(15);
std::cout << std::clock() << std::endl;
return 0;
}
That program always outputs "0". Documentation on clock() says that it should return clock ticks since program started, which with the 15
second sleep that should be plenty. I don''t understand.
#include <ctime>
#include <cstdlib>
#include <iostream>
using namespace std;
int main()
{
sleep(10);
cout << clock() << endl;
return 0;
}
Outputs "15".
JetSnaiL wrote:ro**********@gmail.comwrote:
Ok, so I am trying to establish how boost.timer works and I try a
fewthings and afaict it doesn''t. So I open the header to see why and
runsome tests to establish what is going on and it all boils down to
theclock() function. Here is the code:
#include <iostream>
#include <cstdlib>
int main(void)
{
boost::timer tmr;
sleep(15);
std::cout << std::clock() << std::endl;
return 0;
}
That program always outputs "0". Documentation on clock() says that
itshould return clock ticks since program started, which with the 15
second sleep that should be plenty. I don''t understand.
#include <ctime>
#include <cstdlib>
#include <iostream>
using namespace std;
int main()
{
sleep(10);
cout << clock() << endl;
return 0;
}
Outputs "15".
Well, I get 0.
这篇关于时钟()的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!