c / c ++是否具有延迟功能？

Question

c / c ++是否具有延迟/等待/睡眠功能？

Answer 1

C++ does not have a sleep function. But most platforms do.

On Linux you have sleep() and usleep() . On Windows you have Sleep() .

You just have to include the appropriate headers to get access to them.

Answer 2

The closest to a cross-platform sleep function that I know of is in boost::thread. It's called sleep .

However, if you're working on a platform where plain ol' sleep(unsigned int seconds) is available, then I'd just use that.

Answer 3

Depends on the platform. There're sleep() and usleep() for instance.

Answer 4

sleep()? Dunno, just an idea.

Answer 5

啊哈，你可以在Windows中使用Sleep（）。它是一个内核函数，在Linux中是sleep（x）x = mil-sec

Answer 6

sleep is not very accurate, as it only give you seconds granularity and your process might not wake up right on the "dot". If you want much more accurate timer. I would use select system call. both unix and windows have it.

Something like this will sleep for 10 microseconds struct timeval tv;

tv.sec = 0;
tv.tv_usec = 10;
select(0,NULL,NULL,NULL,&tv);

Answer 7

There is no cross platform solution. sleep() is POSIX, not standard C/C++.

You could look at a cross platform library that provides sleep , eg SDL .

Source code .

Answer 8

For cross platform you can design your own Sleep function. See the example below -

MyClass::MySleepMethod(int milisec)
{
 #ifdef WINDOWS
 Sleep(milisec);
 #else
 sleep(milisec);
 #endif
}

Answer 9

I asked the mighty google for it and its first answer goes like:

int x,y;
for(x = 0; x < 2000; x++)
{
    for(y = 0; y < 2000000; y++)
    {
    }
}

But you have to adjust the number in for loop to your system.

time_t start_time, cur_time;
time(&start_time);
do
{
    time(&cur_time);
}
while((cur_time - start_time) < 3);

and

clock_t start_time, cur_time;
start_time = clock();
while((clock() - start_time) < 3 * CLOCKS_PER_SEC)
{
}

and last but not least

There are several other functions that can be used. For Windows computers, there are _ftime, Sleep(), and QueryPerformanceCounter() functions, as well as the sytem timer.