睡眠持续几毫秒

I know the POSIX sleep(x) function makes the program sleep for x seconds. Is there a function to make the program sleep for x milliseconds in C++?

Note that there is no standard C API for milliseconds, so (on Unix) you will have to settle for usleep, which accepts microseconds:

#include <unistd.h>

unsigned int microseconds;
...
usleep(microseconds);

To stay portable you could use Boost::Thread for sleeping:

#include <boost/thread/thread.hpp>

int main()
{
    //waits 2 seconds
    boost::this_thread::sleep( boost::posix_time::seconds(1) );
    boost::this_thread::sleep( boost::posix_time::milliseconds(1000) );

    return 0;
}

This answer is a duplicate and has been posted in this question before. Perhaps you could find some usable answers there too.

nanosleep is a better choice than usleep - it is more resilient against interrupts.

Depending on your platform you may have usleep or nanosleep available. usleep is deprecated and has been deleted from the most recent POSIX standard; nanosleep is preferred.

In Unix you can use usleep.

In Windows there is Sleep.

Select call is a way of having more precision (sleep time can be specified in nanoseconds).

In C++11, you can do this with standard library facilities:

#include <chrono>
#include <thread>

std::this_thread::sleep_for(std::chrono::milliseconds(x));

Clear and readable, no more need to guess at what units the sleep() function takes.

#include <WinBase.h>

Syntax:

Sleep (  __in DWORD dwMilliseconds   );

Usage:

Sleep (1000); //Sleeps for 1000 ms or 1 sec

Why don't use time.h library? Runs on Windows and POSIX systems:

#include <iostream>
#include <time.h>

using namespace std;

void sleepcp(int milliseconds);

void sleepcp(int milliseconds) // Cross-platform sleep function
{
    clock_t time_end;
    time_end = clock() + milliseconds * CLOCKS_PER_SEC/1000;
    while (clock() < time_end)
    {
    }
}
int main()
{
    cout << "Hi! At the count to 3, I'll die! :)" << endl;
    sleepcp(3000);
    cout << "urrrrggghhhh!" << endl;
}

Corrected code - now CPU stays in IDLE state [2014.05.24]:

#include <iostream>
#ifdef WIN32
    #include <windows.h>
#else
    #include <unistd.h>
#endif // win32

using namespace std;

void sleepcp(int milliseconds);

void sleepcp(int milliseconds) // Cross-platform sleep function
{
    #ifdef WIN32
        Sleep(milliseconds);
    #else
        usleep(milliseconds * 1000);
    #endif // win32
}
int main()
{
    cout << "Hi! At the count to 3, I'll die! :)" << endl;
    sleepcp(3000);
    cout << "urrrrggghhhh!" << endl;
}

The way to sleep your program in C++ is the Sleep(int) method. The header file for it is #include "windows.h."

For example:

#include "stdafx.h"
#include "windows.h"
#include "iostream"
using namespace std;

int main()
{
    int x = 6000;
    Sleep(x);
    cout << "6 seconds have passed" << endl;
    return 0;
}

The time it sleeps is measured in milliseconds and has no limit.

Second = 1000 milliseconds
Minute = 60000 milliseconds
Hour = 3600000 milliseconds

If using MS Visual C++ 10.0, you can do this with standard library facilities:

Concurrency::wait(milliseconds);

you will need:

#include <concrt.h>

On platforms with the select function (POSIX, Linux, and Windows) you could do:

void sleep(unsigned long msec) {
    timeval delay = {msec / 1000, msec % 1000 * 1000};
    int rc = ::select(0, NULL, NULL, NULL, &delay);
    if(-1 == rc) {
        // Handle signals by continuing to sleep or return immediately.
    }
}

However, there are better alternatives available nowadays.

Use Boost asynchronous input/output threads, sleep for x milliseconds;

#include <boost/thread.hpp>
#include <boost/asio.hpp>

boost::thread::sleep(boost::get_system_time() + boost::posix_time::millisec(1000));

As a Win32 replacement for POSIX systems:

void Sleep(unsigned int milliseconds) {
    usleep(milliseconds * 1000);
}

while (1) {
    printf(".");
    Sleep((unsigned int)(1000.0f/20.0f)); // 20 fps
}