spawn or execvm?

[tortuosit 485]

Hi guys,

in my weather mod I use independent rain/wind threads. I call it thread, what I mean is an independently running script, usually running in an endless loop. From the main script I simply called them via "rainhandle=execvm 'scriptwithwhileloop'". I don't know of what data type rainhandle is, but least I can say I was able to kill the threads via this handle, I also need to reliably kill threads. This is usually done via "terminate" command or setting a binary global variable (inside the script there is usually "while (a_globalvariable) do {"

BTW, How can I determine if a thread is running? I hoped there would be some kind of taskmanager. Well I only could see it with producing some output from these threads. No output=thread dead...

OK, now I often see people using "[] spawn {usually_a_loop}". Should I go this way?

Important point is performance. What's better? As less loops as possible? sleep() as long as possible?

Thanks for your input :)

[dreadedentity 278]

From the order I identified questions from:

1. You can always stop a script from running using terminate, provided you know the script handle.

2. scriptDone and you can also use scriptNull to determine whether a script has ever run or not

3. It depends on what you want to do, if you need a constant update, use a loop with no sleep. If the results don't matter as much, you can use a loop with sleep.

[cuel 25]

These are the same thing

_handle = [] execVM "script1.sqf":
_handle = [] spawn {_this call compile preProcessFileLineNumbers "script1.sqf"}

To see if a thread is still running you can use scriptDone

As to your last question: it depends entirely on what your loops are doing, and what for.

[dreadedentity 278]

It's also important to note that if you run a script or spawn a thread, the code will run until the end then terminate itself. That's the reason most people, myself included, will use an infinite loop. It's also usually for testing/debug purposes

[7rust 10]

Small question: How many spawn-threads can be opened in Arma 3? Is there any number or any maximum? I guess its depending on servers hardware is it?

[tortuosit 485]

Thanks for the hint about scriptDone and scriptNull.

Just for the theory. What if I do:

_handle = [args] execVM "script1.sqf";

and later again

_handle = [args] execVM "script1.sqf";

without having terminated the first one? I'd have no chance to stop the first incarnation of script1.sqf manually. Is that correct? I haven't got the handle of the first one and therefore there is no way to stop it. Thats also a reason why I use "while {youareallowedtorun} do {" - so I can set youareallowedtorun=false from outside and the loop would stop after all sleeping has ended.

_handle = [] spawn {_this call compile preProcessFileLineNumbers "script1.sqf"}

Ah I see, with spawn I could open a new thread and keep the code inline... may be useful thx.

Edited November 8, 2014 by tortuosit

[Tajin 348]

_handle = [args] execVM "script1.sqf";

and later again

_handle = [args] execVM "script1.sqf";

The second execVM would overwrite the first handle (if that script is still running).

If you want to avoid that you could also save your script-handles in an array.:

_handles = [];

_handles pushback ( [args] execVM "script1.sqf" );

and later again

_handles pushback ( [args] execVM "script1.sqf" );

_handle = [] spawn {_this call compile preProcessFileLineNumbers "script1.sqf"}

Keep in mind that this is only an example, so don't use that construct!

execVM does exactly the same and spawn only makes sense when you have inline code.

[dreadedentity 278]

Small question: How many spawn-threads can be opened in Arma 3? Is there any number or any maximum? I guess its depending on servers hardware is it?

I made a test for this. I'm not sure if it's hardware specific or not. For my computer, a lot. I opened >1000 threads all with a waitUntil inside, still didn't see performance loss.

[iceman77 18]

Hmm. I don't think it matters how many threads and waitUntils. I think it just matters what's in them.

Edited November 8, 2014 by Iceman77

[das attorney 857]

Hmm. I don't think it matters how many threads and waitUntils. I think it just matters what's in them.

This ^^^

1 thread of map wide nearestObject checks is way more than intensive than 1000 of _val = 1 + 1; hint str _val

[7rust 10]

Hmm. I don't think it matters how many threads and waitUntils. I think it just matters what's in them.

Alright, thanks guys!