[libuv] libuv cost lot's of cpu.

[sonygod]

libuv cost lot's of cpu.

why libuv cost lot's of cpu.

just an instance of tcp.

class Main {
	static function main() {
	

		var loop = hl.uv.Loop.getDefault();
	
		var tcp = new hl.uv.Tcp(loop);//cost more than 50%~90% of single cpu
	}
}

hl 1.12.0

[sonygod]

@ncannasse will you take a look?

[ncannasse]

I think this is by design, and definitely not HashLink related.

[RealyUniqueName]

I think this happens because of the integration of libuv's default loop into Haxe's MainLoop:

loopEvent = haxe.MainLoop.add(function() {
	// if no more things to process, stop
	if (def.run(NoWait) == 0) {
		loopEvent.stop();
		loopEvent = null;
	}
});

https://github.com/HaxeFoundation/haxe/blob/fe23a92264be3853dddb03cf664595f2a07aa196/std/hl/uv/Loop.hx#L49-L55
Since tcp handler is alive, def.run(NoWait) immediately returns non-zero value. And then MainLoop immediately runs the next tick because loopEvent is not stopped.
These PRs should address the issue: #464, HaxeFoundation/haxe#10342