Thread overview
Good News: Almost all druntime supported on arsd webassembly
Jan 06
Hipreme
January 06

Hello people. I have tried working again with adam's wasm minimal runtime, and yesterday I was able to make a great progress on it.

Currently, the only feature that I did not bother to implement support for was the try/catch/finally/throw friends. Pretty much only because I don't use in my engine. I would like to ask you guys some feedback on its current usage, I have written a file with only tests to the wasm runtime:

// ldc2 -i=. --d-version=CarelessAlocation -i=std -Iarsd-webassembly/ -L-allow-undefined -ofserver/omg.wasm -mtriple=wasm32-unknown-unknown-wasm arsd-webassembly/core/arsd/aa arsd-webassembly/core/arsd/objectutils arsd-webassembly/core/internal/utf arsd-webassembly/core/arsd/utf_decoding hello arsd-webassembly/object.d

import arsd.webassembly;
import std.stdio;

class A {
	int _b = 200;
	int a() { return 123; }
}

interface C {
	void test();
}
interface D {
	void check();
}

class B : A, C
{
	int val;
	override int a() { return 455 + val; }

	void test()
	{
		rawlog(a());
		int[] a;
		a~= 1;
	}
}

void rawlog(Args...)(Args a, string file = __FILE__, size_t line = __LINE__)
{
	writeln(a, " at "~ file~ ":", line);
}


struct Tester
{
	int b = 50;
	string a = "hello";
}
void main()
{
	float[] f = new float[4];
	assert(f[0] is float.init);
	f~= 5.5; //Append
	f~= [3, 4];
	int[] inlineConcatTest = [1, 2] ~ [3, 4];

	auto dg = delegate()
	{
		writeln(inlineConcatTest[0], f[1]);
	};
	dg();
	B b = new B;
	b.val = 5;
	A a = b;
	a.a();
	C c = b;
	c.test();
	assert(cast(D)c is null);
	Tester[] t = new Tester[10];
	assert(t[0] == Tester.init);
	assert(t.length == 10);

	switch("hello")
	{
		case "test":
			writeln("broken");
			break;
		case "hello":
			writeln("Working switch string");
			break;
		default: writeln("What happenned here?");
	}
	string strTest = "test"[0..$];
	assert(strTest == "test");

	
	Tester* structObj = new Tester(50_000, "Inline Allocation");
	writeln(structObj is null, structObj.a, structObj.b);

	int[string] hello = ["hello": 500];
	assert(("hello" in hello) !is null, "No key hello yet...");
	assert(hello["hello"] == 500, "Not 500");
	hello["hello"] = 1200;
	assert(hello["hello"] == 1200, "Reassign didn't work");
	hello["h2o"] = 250;
	assert(hello["h2o"] == 250, "New member");


	int[] appendTest;
	appendTest~= 50;
	appendTest~= 500;
	appendTest~= 5000;
	foreach(v; appendTest)
		writeln(v);
	string strConcatTest;
	strConcatTest~= "Hello";
	strConcatTest~= "World";
	writeln(strConcatTest);
	int[] intConcatTest = cast(int[2])[1, 2];
	intConcatTest~= 50;
	string decInput = "a";
	decInput~= "こんいちは";
	foreach(dchar ch; "こんいちは")
	{
		decInput~= ch;
		writeln(ch);
	}
	writeln(decInput);
	int[] arrCastTest = [int.max];

	foreach(v; cast(ubyte[])arrCastTest)
		writeln(v);

}

All those tests are currently passing. That means we almost got all the common features from the D Runtime into Arsd custom runtime. Meaning that the only thing that would be missing right now being the WASI libc. But my engine is not going to use it entirely, only a subset of it. So, I would like to say that whoever wants to play with it now is able to do it so.

That being said, I would carefully advice that while I bring those implementations, I didn't care about memory leaks, so, it is a runtime without GC: careless allocations. But! It is possible to port some programs specially if you're already doing house clearing yourself. As my engine does not leak memory in loop (as that would make it trigger the GC and thus make it slow), it is totally possible to use it.

"But why didn't you continued Skoppe's WASM work?", I literally am not able to build LDC runtime no matter how hard I tried. Doing that work on a minimal runtime was a lot easier.

If you do find any use in the work I've done, please do test it as I'll benefit from both you guys test. If you find any performance improvement on it, it'll be gladly be accepted.

I do not intend to replace the druntime with that. I've done the minimal subset of features that makes my engine work for the web. A real druntime is still expected and awaited by me.

The link to the PR to be tested can be found there: https://github.com/adamdruppe/webassembly/pull/9

January 06
On Fri, Jan 06, 2023 at 12:52:43PM +0000, Hipreme via Digitalmars-d-announce wrote:
> Hello people. I have tried working again with adam's wasm minimal runtime, and yesterday I was able to make a great progress on it.
[...]
> All those tests are currently passing. That means we almost got all the common features from the D Runtime into Arsd custom runtime. Meaning that the only thing that would be missing right now being the WASI libc. But my engine is not going to use it entirely, only a subset of it. So, I would like to say that whoever wants to play with it now is able to do it so.
> 
> 
> That being said, I would carefully advice that while I bring those implementations, I didn't care about memory leaks, so, it is a runtime without GC: careless allocations. But! It is possible to port some programs specially if you're already doing house clearing yourself. As my engine does not leak memory in loop (as that would make it trigger the GC and thus make it slow), it is totally possible to use it.
[...]

This is awesome stuff, thanks for pushing ahead with it!!  Keep this up, and I might actually decide to use your game engine for my projects. ;-)

The big question I have right now is, what's the status of interfacing with web APIs such as WebGL?  How much JS glue is needed for that to work?  My dream is for all of the JS boilerplate to be automated away, so that I don't have to write a single line of JS for my D project to work in WASM.


T

-- 
Those who don't understand Unix are condemned to reinvent it, poorly.
January 06

On Friday, 6 January 2023 at 12:52:43 UTC, Hipreme wrote:

>

Hello people. I have tried working again with adam's wasm minimal runtime, and yesterday I was able to make a great progress on it.

[...]
This sounds great. Thank you for your efforts. I will play around with it someday. I have not touched my pet game a while [1]. I used emscripten for sdl, and skoppe's druntime fork.

One question. Does GC work with Adam's druntime for wasm? If yes, how? IMHO, D's GC need a second thread, which is a problem with wasm.

1: https://github.com/aferust/drawee

January 06
On Friday, 6 January 2023 at 22:13:15 UTC, H. S. Teoh wrote:
> The big question I have right now is, what's the status of interfacing with web APIs such as WebGL?

This part is really easy, you can call it from D with the opDispatch or pass it through as eval strings.
January 06
On Friday, 6 January 2023 at 22:14:23 UTC, Ferhat Kurtulmuş wrote:
> One question. Does GC work with Adam's druntime for wasm?

I haven't actually written one yet, so it leaks if you don't pay attention yourself. But I have a plan that should work: you do the setTimeout(collect, 0) so it runs when the event loop is idle. Then the wasm stack is empty so you can scan pure memory.

> IMHO, D's GC need a second thread

This isn't true, it never needs a second thread, even on normal desktop.

The problem with GC on wasm is the webasm stack is opaque. You can have the compiler output a shadow stack or my plan of scanning when it is empty. Either should work but I haven't had time to implement anything.

January 07

On Friday, 6 January 2023 at 12:52:43 UTC, Hipreme wrote:

>

Hello people. I have tried working again with adam's wasm minimal runtime, and yesterday I was able to make a great progress on it.

Awesome! To think that custom druntime can get you out of platform situations is great risk reduction.

January 09
On Friday, 6 January 2023 at 22:39:36 UTC, Adam D Ruppe wrote:
> On Friday, 6 January 2023 at 22:14:23 UTC, Ferhat Kurtulmuş wrote:
>> One question. Does GC work with Adam's druntime for wasm?
>
> I haven't actually written one yet, so it leaks if you don't pay attention yourself. But I have a plan that should work: you do the setTimeout(collect, 0) so it runs when the event loop is idle. Then the wasm stack is empty so you can scan pure memory.
>
>> IMHO, D's GC need a second thread
>
> This isn't true, it never needs a second thread, even on normal desktop.
>
> The problem with GC on wasm is the webasm stack is opaque. You can have the compiler output a shadow stack or my plan of scanning when it is empty. Either should work but I haven't had time to implement anything.

thank you for the clarification, Adam.