void test(string line){
...
};


void main(){
  string[] list;
  foreach (line; list)
    new Thread({test(line);}).start();
...
}

On 10/16/2016 03:22 PM, markov wrote:
>
> void test(string line){
> ...
> };
>
>
> void main(){
>   string[] list;
>   foreach (line; list)
>     new Thread({test(line);}).start();
> ...
> }
>

It works in an unexpected way: In D, all those threads would close over the same 'line' loop variable, which happens to point to the last string, so they all see the last string:

import std.stdio;
import core.thread;

void test(size_t i, string line){
    writefln("Thread %s: %s", i, line);
}

void main(){
    string[] list = [ "hello", "world" ];
    foreach (i, line; list)
        new Thread({test(i, line);}).start();
}

Prints:

Thread 1: world    // <-- Expected 0 and "hello"
Thread 1: world

What needs to happen is to give the thread separate variables. An easy solution is to start the thread with the arguments of a function:

    foreach (i, line; list) {
        void startThread(size_t j, string l) {
            new Thread({test(j, l);}).start();    // <-- Uses function
                                                  //     arguments
        }
        startThread(i, line);
    }

I happened to define a nested function. You can define it anywhere else.

Ali

Thanks.

So something like this would be helpful in core.thread?

void startThread(alias fun, P...)(P p){
    new Thread({fun(p);}).start();
}

Dne 17.10.2016 v 11:56 markov via Digitalmars-d-learn napsal(a):

> Thanks.
>
> So something like this would be helpful in core.thread?
>
> void startThread(alias fun, P...)(P p){
>     new Thread({fun(p);}).start();
> }
>
or without delegate

import std.stdio;
import core.thread;

void fun(alias a, alias msg)()
{
    writefln("Hello number %d from %s", a, msg);
}

void main()
{
    int a = 7;
    string msg = "main";
    auto thr = new Thread(&fun!(a, msg)).start;
    thr.join;
}