Inaccurate Time

[luainin]

Thank you for writing luaunit -- it's very simple to use.

It seems that the timings for the test runs are inaccurate -- I believe this is due to the usage of os.clock() which measures only Lua engine cpu time, as opposed to "real time" (at least in my experience). Unfortunately, I have code that makes http calls (yes, these are not "pure" unit tests), which makes calls to C functions and thus, do not factor into the "total" time for a test.

Any suggestions on how to go about this issue? I replaced all appropriate os.clock() invocations with os.time(os.date("!*t")). This gave much more accurate results; however, the precision was only to the second.

[bluebird75]

Sorry, I totally missed your report.

In lua, we are limited to what the lua api provides. As you found out, it's one of : time(), date(), clock() . See https://www.lua.org/manual/5.4/manual.html#6.9

Using os.clock() was a mistake now that I reread the documentation. When choosing it, I was happy because it was the only one with sub-second precision but I missed the fact that it is not measuring time but CPU-time. So, not the right choice for my goal.

The other functions do not go beyound second precision, which is a pity. In theory, time() returns a double which would be fine for us.

I'll try to look more into the topic but with stock lua, there is not much more we can do.

[bluebird75]

Threre are basically two solution to your problem. It's been a long time so I guessed you figured it out already but still.

Solution 1 : depend on an external package providing a more precise time function. Many external lua librarires provide this, See different solutions proposed in : https://stackoverflow.com/questions/463101/lua-current-time-in-milliseconds/66402619#66402619

However, I want luaunit to stay standalone.

So, I'll go with solution 2 : use os.popen to ask the shell for a more precise time. I'll go with this for a future version of luaunit. And I will also state this clearly in the documentation, and provide an easy way to replace the timing function().

And in the meantime, I will change os.clock() to os.time()

Thanks for your report.

[denisdemaisbr]

maybe

• try os.clock() or
• socket.gettime() (from luasocket)

https://stackoverflow.com/questions/463101/lua-current-time-in-milliseconds

[luainin]

@bluebird75 Thanks so much for your response:) Yeah, I had ended up making a copy of luaunit and made a few custom additions to the library to fit our needs, among which was the time modification.

Sorry for not closing the issue sooner -- I had forgotten all about it since this was a simple fix on our end:)