goroutines vs vibe.d tasks

[Sönke Ludwig via Digitalmars-d-learn]

Am 01.07.2015 um 20:09 schrieb Mathias Lang:
> On Tuesday, 30 June 2015 at 15:18:36 UTC, Jack Applegame wrote:
>> Just creating a bunch (10k) of sleeping (for 100 msecs) goroutines/tasks.
>>
>> Compilers
>> go:     go version go1.4.2 linux/amd64
>> vibe.d: DMD64 D Compiler v2.067.1 linux/amd64, vibe.d 0.7.23
>>
>> Code
>> go:     http://pastebin.com/2zBnGBpt
>> vibe.d: http://pastebin.com/JkpwSe47
>>
>> go version build with     "go build test.go"
>> vibe.d version built with "dub build --build=release test.d"
>>
>> Results on my machine:
>>
>> go:     168.736462ms (overhead ~ 68ms)
>> vibe.d: 1944ms       (overhead ~ 1844ms)
>>
>> Why creating of vibe.d tasks is so slow (more then 10 times)???
>
> In your dub.json, can you use the following:
>
>      "subConfigurations": {
>          "vibe-d": "libasync"
>      },
>      "dependencies": {
>          "vibe-d": "~>0.7.24-beta.3"
>      },
>
>
> Turns out it makes it much faster on my machine (371ms vs 1474ms). I
> guess it could be a good thing to investigate if we can make it the
> default in 0.7.25.

This sounds like the event_del() + event_add() sequence that is done in 
the libevent driver causes this slowdown. If anyone knows of a faster 
way to rearm a timer for libevent that would be great. Otherwise I don't 
really know what to do about this (other than using a different driver).

As for libasync, making it the default is maybe still a little too 
early, but we should definitely think about how to make it more 
prominent for testing (maybe even still for 0.7.24).