How to measure LUA run time in milliseconds ?

[BitBucket 13]

Hi all,

To optimize LUA code I would like to measure run time in milliseconds.

os.clock() and os.time() just support seconds (too coarse).

Found this LUA-code on the web but I just get errors.

----------------

require "socket"

local t = socket.gettime()

----------------

Any suggestions?

[Krikroff 199]

BitBucket, i use this

Please login or register to see this code.

The principle is to use os.clock()

Please login or register to see this image.

/emoticons/default_icon_wink.gif" alt=";-)" />

[Dalle1985 16]

You can't do that in Lua on the fibaro box. You are requiring an external dependancy (a file) which you don't have access to (or might not even exist).

What your code is doing is to try and load in a module called "socket" (require means that it will include the file you require into your code) from any valid location and then get the function gettime() from socket. However, your lua instance does not have a "socket" library in any directory it has access to and will thus just return an error.

You will have to make due with seconds - Lua doesn't support ms resolution.

[Krikroff 199]

Dalle1985, The os.clock() function returns the CPU time since Lua started in seconds, with milliseconds precision.

[rolcsi11 2]

What if I want to make socket read/write periodically to send requests and get responses. I would like to measurue the response time. So that the CPU time is almost zero, while waiting for the response and the time is the faction of one second. Is there a way to get milliseconds of real time.

[jgab 2,642]

3 hours ago, rolcsi11 said:

What if I want to make socket read/write periodically to send requests and get responses. I would like to measurue the response time. So that the CPU time is almost zero, while waiting for the response and the time is the faction of one second. Is there a way to get milliseconds of real time.

Yes but no.
os.clock() returns the elapsed cpu time with milliseconds resolution (a floating point number)

So

Please login or register to see this code.

This works to time the loop with ms resolution. Because no other code is running besides the loop.
However, most I/O (net.*) functions have callbacks when data is read. That means that other parts of your code (or QA internal code) could run while waiting for your callback to be called. This could consume additional cpu cycles making the reading return that time and not the time you wait for data. In fact, if no other code runs while you wait for callback I would expect that os.clock() diff would be close to zero as the internals probably hangs on a socket read consuming no cpu.
Otherwise, to time absolute time, we only have os.time() that is only seconds resolution.

Edited November 13, 2024 by jgab