Basically I'm interested in measuring the following two kinds of time:
- Absolute time (or wall-clock time): the time elapsed in the real world.
- CPU time: the amount of time that CPUs have spent running the function.
The .Net class System.Diagnostics.Stopwatch can be used to measure absolute time. And the TotalProcessorTime property of System.Diagnostics.Process returns a TimeSpan object, which indicates the amount of CPU time that the associated process has spent running the F# function.
let time f =
let proc = Process.GetCurrentProcess()
let cpu_time_stamp = proc.TotalProcessorTime
let timer = new Stopwatch()
let cpu_time = (proc.TotalProcessorTime-cpu_time_stamp).TotalMilliseconds
printfn "CPU time = %dms" (int64 cpu_time)
printfn "Absolute time = %dms" timer.ElapsedMilliseconds
let rec loop n f x =
if n > 0 then
f x |> ignore
loop (n-1) f x
time (fun () -> loop 1000000 List.sum [1..100])