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考虑以下示例，在 windows 7 icore7 笔记本电脑（VC++2010）和 ubuntu 64bit 12.04 lte gcc 4.6.3

#include <iostream>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/thread/thread.hpp>
typedef boost::posix_time::ptime Time;
typedef boost::posix_time::time_duration TimeDuration;
int main()
{
    Time t1;
    Time t2;
    TimeDuration dt;
    boost::posix_time::microseconds tosleep=boost::posix_time::microseconds(100);
    for(int i=0;i<10;i++){

        t1=boost::posix_time::microsec_clock::local_time();
        //std::cout <<i << std::endl; // on win7 without this all outputs are 0
        boost::this_thread::sleep( tosleep );

        t2=boost::posix_time::microsec_clock::local_time();

        dt = t2 - t1;
        long long msec = dt.total_microseconds();
        std::cout << msec << std::endl;
    }
    return 0;
}

我原以为我的线程会持续休眠 100 微秒，但输出有点奇怪：

=========== AND OUTPUT ==================
arm2arm@cudastartub:~$ g++ -O3 sleepme.cpp -lboost_thread
arm2arm@cudastartub:~$ ./a.out
726
346
312
311
513
327
394
311
306
445

boost有一些开销吗？对于微秒很重要的实时系统，我需要什么？

4

1 回答 1

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On Windows one can't Sleep() less than 1 ms, so your sleep(tosleep) call is equivalent to sleep(0). (See also this link)

Of course, std::cout <<i << std::endl would take some time...

于 2012-06-13T08:52:23.397 回答