Getting system time with high precision

[Leigh Sharpe]

Hi all,
Is there any way of getting the system time, right down to the microsecond,
or even millisecond?

I need to do something a little like this:

int start_time=getTheTimeSomehow(); // Get the current time
doSomethingElse(); // Go and do something
else.
int end_time=getTheTimeSomehow() // What's the time now?
int elapsed_time=end_time-start_time; // How long did it take?

And I need to know the time as accurately as possible.


I would expect there to be a function somewhere, but I just don't know
where.

 

[Sarath]

Hi all,
Is there any way of getting the system time, right down to the microsecond,
or even millisecond?

I need to do something a little like this:

int start_time=getTheTimeSomehow(); // Get the current time
doSomethingElse(); // Go and do something
else.
int end_time=getTheTimeSomehow() // What's the time now?
int elapsed_time=end_time-start_time; // How long did it take?

And I need to know the time as accurately as possible.

I would expect there to be a function somewhere, but I just don't know
where.

Check the following link for sample snippet if you using Visual C++

http://msdn.microsoft.com/library/d.../vccore98/HTML/_crt_strftime.2c_.wcsftime.asp

 

[Ian Collins]

Hi all,
Is there any way of getting the system time, right down to the microsecond,
or even millisecond?

Very likely, but not in a portable way, try an operating system specific
group.

 

[Sherm Pendley]

Is there any way of getting the system time, right down to the microsecond,
or even millisecond?

Not in standard C++. There may be OS-specific functions that provide that
capability for your OS, but those wouldn't be on-topic for this group. I'd
suggest asking in a group that's focused on the capabilities of the OS you're
writing for.

sherm--

 

[Leigh Sharpe]

I'd
suggest asking in a group that's focused on the capabilities of the OS you're
writing for.

OK. That's the second response along those lines. Which prompts the
question, which group would that be? My target platform is Linux.

 

[red floyd]

OK. That's the second response along those lines. Which prompts the
question, which group would that be? My target platform is Linux.

You might want to check the FAQ. They ahve a suggested list.

http://www.parashift.com/c++-faq-lite/how-to-post.html#faq-5.9

 

[liam_herron]

On windows I would use:
QueryPerformanceCounter located in <windows.h>

On Linux I would use:
::gettimeofday located in <sys/time.h>

example Linux Use:

#include <sys/time.h>

const long long TICKS_PER_SECOND = 1000000L;

struct timeval tv;
struct timezone tz;
::gettimeofday(&tv, &tz);
long long quadPart = tv.tv_sec * TICKS_PER_SECOND + tv.tv_usec;

Hope that helps,
Liam

 

[Larry Smith]

OK. That's the second response along those lines. Which prompts the
question, which group would that be? My target platform is Linux.

Try one of these:

comp.os.linux.development.system
comp.os.linux.development.apps