What is the unit of gettimeofday()?

c++ c gettimeofday
John picture John · Jul 25, 2013 · Viewed 15.5k times · Source

I've a program to calculate the latency of an object in a pub-sub model. I've used the following function for timestamp:

uint64_t GetTimeStamp() {
    struct timeval tv;
    gettimeofday(&tv,NULL);
    return tv.tv_sec*(uint64_t)1000000+tv.tv_usec;
}

The latency is measured as timestamp difference in publisher and subscriber. So, I'm concerned about the unit of the latency measured. Is it in seconds or microseconds??

Answer

Karthikeyan picture Karthikeyan · Jul 25, 2013

The timeval structure has tv_sec, which gives you the absolute value for the seconds, and tv_usec, which gives you the remaining fraction in micro seconds.

So, you could get the resolution in micro seconds.

For more information, http://www.gnu.org/software/libc/manual/html_node/Elapsed-Time.html

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