rdmd takes 2-3 seconds on a first-run of a simple .d script

[BoQsc]

On Sunday, 26 May 2019 at 20:37:36 UTC, Jon Degenhardt wrote:
> On Saturday, 25 May 2019 at 22:18:16 UTC, Andre Pany wrote:
>> On Saturday, 25 May 2019 at 08:32:08 UTC, BoQsc wrote:
>>> I have a simple standard .d script and I'm getting annoyed 
>>> that it takes 2-3 seconds to run and see the results via rdmd.
>>
>> Also please keep in mind there could be other factors like 
>> slow disks, anti virus scanners,... which causes a slow down.
>
> I have seen similar behavior that I attribute to virus scan 
> software. After compiling a program, the first run takes 
> several seconds to run, after that it runs immediately. I'm 
> assuming the first run of an unknown binary triggers a scan, 
> though I cannot be completely sure.
>
> Try compiling a new binary in D or C++ and see if a similar 
> effect is seen.
>
> --Jon

The desktop computer I'm testing this on contains Solid State 
Drive, a Windows 10 Home Operating system and about 7-9 years old 
of hardware. But remember, we are living in a 21 century, the 
hardware performance is great, even for the old hardware that is 
10 years old, especially the desktops.

I tried to disable Windows Defender real-time protection, it 
didn't helped to speed up rdmd. However until I test it on Linux, 
I can't be sure if Windows do not have other less obvious quirks 
that could slow down third party programs such as D compiler or 
rdmd.