Under Windows there are some handy functions like QueryPerformanceCounter from mmsystem.h to create a high resolution timer.
Is there something similar for Linux?
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stackoverflow.com/a/5524138/183120 (Cross-platform C++11 standard high resolution timer)legends2k– legends2k2013-05-15 14:17:05 +00:00Commented May 15, 2013 at 14:17
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6 Answers
It's been asked before here -- but basically, there is a boost ptime function you can use, or a POSIX clock_gettime() function which can serve basically the same purpose.
3 Comments
okoman
Didn't know that Boost provides timer functionality. Thank you :)
lothar
Or use the HighResTimer from the ACE library.
BD at Rivenhill
@lothar: +1 for pointer to ACE library, thanks. The link you gave was stale, here's a new one: dre.vanderbilt.edu/Doxygen/Stable/libace-doc/a00227.html
For Linux (and BSD) you want to use clock_gettime().
#include <sys/time.h>
int main()
{
timespec ts;
// clock_gettime(CLOCK_MONOTONIC, &ts); // Works on FreeBSD
clock_gettime(CLOCK_REALTIME, &ts); // Works on Linux
}
See: This answer for more information
1 Comment
bdonlan
Of course, you need to be aware of the difference between
CLOCK_MONOTONIC and CLOCK_REALTIME - the former has its zero-point set to something arbitrary at system boot, and as such is only useful for relative comparisons between two CLOCK_MONOTONIC measurements (but is unaffected by wallclock adjustments)Here's a link describing how to do high-resolution timing on Linux and Windows... and no, Don't use RTSC.
Comments
With C++11, use std::chrono::high_resolution_clock.
Example:
#include <iostream>
#include <chrono>
typedef std::chrono::high_resolution_clock Clock;
int main()
{
auto t1 = Clock::now();
auto t2 = Clock::now();
std::cout << "Delta t2-t1: "
<< std::chrono::duration_cast<std::chrono::nanoseconds>(t2 - t1).count()
<< " nanoseconds" << std::endl;
}
Output:
Delta t2-t1: 131 nanoseconds
Comments
I have nothing but this link: http://www.mjmwired.net/kernel/Documentation/rtc.txt
I'm pretty sure RTC is what you are looking for though.
EDIT
Other answers seem more portable than mine.
Comments
For my money, there is no easier-to-use cross-platform timer than Qt's QTime class.
