I am doing very small link-checker. Here is' code https://run.dlang.io/is/p8whrA

I am expecting that on line:
writefln("url: %s, status: %s", url.url, url.status);

I will print link and it's status. But I am getting only:
url: http://127.0.0.1:8081/hck, status:
url: http://127.0.0.1:8081/hck2, status:
url: http://127.0.0.1:8081/hck3, status:

It's seems that I missed something with refs? Could you help me find error?

On Thursday, 24 January 2019 at 15:28:19 UTC, Suliman wrote:
> I am doing very small link-checker. Here is' code https://run.dlang.io/is/p8whrA
>
> I am expecting that on line:
> writefln("url: %s, status: %s", url.url, url.status);
>
> I will print link and it's status. But I am getting only:
> url: http://127.0.0.1:8081/hck, status:
> url: http://127.0.0.1:8081/hck2, status:
> url: http://127.0.0.1:8081/hck3, status:
>
> It's seems that I missed something with refs? Could you help me find error?

It's because runWorkerTask internally passes its arguments along to the function by value:

https://github.com/vibe-d/vibe.d/blob/master/core/vibe/core/core.d#L364

The workaround is to pass a pointer instead:

    void getServiceStatus(MyUrl* url) {
        // ...
    }

    // ...

    runWorkerTask(&getServiceStatus, &url);

> It's because runWorkerTask internally passes its arguments along to the function by value:
>
> https://github.com/vibe-d/vibe.d/blob/master/core/vibe/core/core.d#L364
>
> The workaround is to pass a pointer instead:
>
>     void getServiceStatus(MyUrl* url) {
>         // ...
>     }
>
>     // ...
>
>     runWorkerTask(&getServiceStatus, &url);


void getServiceStatus(MyUrl* url)
{
...
}


 Error: static assert:  "Cannot convert arguments '(MyUrl)' to function arguments '(MyUrl*)'."

On Thursday, 24 January 2019 at 16:04:06 UTC, Suliman wrote:
>  Error: static assert:  "Cannot convert arguments '(MyUrl)' to function arguments '(MyUrl*)'."

You've forgotten to change the call site to pass a pointer.

However, it turns out that even if you do that, vibe will not allow you to pass a pointer in this situation:

.dub/packages/vibe-core-1.5.0/vibe-core/source/vibe/core/taskpool.d(114,21): Error: static assert:  "Argument type MyUrl* is not safe to pass between threads."

So, I'm not sure what the best solution here is.

On Thursday, 24 January 2019 at 21:25:45 UTC, Paul Backus wrote:
> So, I'm not sure what the best solution here is.

The best solution is just to pass a copy since there's no absolute need for a reference to be passed.

On Thursday, 24 January 2019 at 22:02:36 UTC, bauss wrote:
> On Thursday, 24 January 2019 at 21:25:45 UTC, Paul Backus wrote:
>> So, I'm not sure what the best solution here is.
>
> The best solution is just to pass a copy since there's no absolute need for a reference to be passed.

But if I will pass copy how I can create array of structures with correct response status?

Create new structures?

Do I need in my code `ref`s ? https://run.dlang.io/is/8dtkC7
Or if vibed doing copy under the hood `ref`s useless?

On Thursday, 24 January 2019 at 15:28:19 UTC, Suliman wrote:
> I am doing very small link-checker. Here is' code https://run.dlang.io/is/p8whrA
>
> I am expecting that on line:
> writefln("url: %s, status: %s", url.url, url.status);
>
> I will print link and it's status. But I am getting only:
> url: http://127.0.0.1:8081/hck, status:
> url: http://127.0.0.1:8081/hck2, status:
> url: http://127.0.0.1:8081/hck3, status:
>
> It's seems that I missed something with refs? Could you help me find error?

You're writing asynchronous code and expecting it to process synchronized. Just make a synchronous call. If you need async use message passing with concurrency, probability on each call to the url so you can do the slow operations in parallel.