stopwatch with time.h possible to be more precise?

Hello,

I am trying to build a simple "stopwatch" timer in C, to be used as a Rubik's Cube timer.
I currently am using time.h, setting up start and stop time_t variables, and the enter key to start and stop the timer, giving the result as the difference between the two. I can post the code but I don't think that's necessary, because it works fine.

My question is how I can make it more precise. It currently only works to the nearest second, when I would like to have it to the nearest millisecond.

Everything I read tells me the most precise C can get is a second, but I find this hard to believe. Does anyone know of a way to do this or can point me in the right direction?

Thanks in advance!

Bryanosaurus,

It has been my experience that measuring time with the C time libraries is highly compiler implementation specific. I just answered another individual with a timer to the nanosecond...http://cboard.cprogramming.com/c-pro...link2-cpp.html. According to the man pages and header files one can adjust the resolution to the millisecond if it is desired. I have used it for pools of threads on several occasions.

I just don't have a compiler handy for it at the moment, but it works great when it's implemented. Let me know if this helps, the code segment with the time measuring variables is #8 (at the bottom), and I included information about the libraries to which one must link. The post originally pertained to the performance advantages of automatic allocation versus dynamic allocation.

Best Regards,

New Ink -- Henry

More accurate timing functions are dependent on the OS you are developing for.

Quote:

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Originally Posted by Bubba

More accurate timing functions are dependent on the OS you are developing for.

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If it helps, I am developing on Linux with, obviously, gcc compiler.

If it's Linux, then gettimeofday() will nominally give you microsecond precision. In reality the precision is significantly less than that, but probably still precise enough for your purposes. It is certainly more precise than a user striking the Enter key, which probably has a jitter of up to a quarter of a second, so it should suffice.

You can look into <timeb.h> functions... There is a struct someplace that includes milliseconds.
Unfortunately even though the resolution is milliseconds, values jump by whatever the tick rate is - was it around 17 per second from the old DOS days? Could be anything.

Still, that may give you sufficient resolution for your needs. At least another 0.1 second of accuracy.

I concur with Brewbuck. After I did some rooting around in the code library, I updated the source's post: http://cboard.cprogramming.com/c-pro...tml#post966497. There was no need to link to an external library either.

Best Regards,

New Ink -- Henry