// I am learning how to send and receive data. The following is my intention, but it cannot be compiled.
// aliases to mutable thread-local data not allowed, what does it mean? thank you.

I am learning how to send and receive. The following is my intention, but it cannot be compiled. Report
import std.concurrency;
import std.stdio;
import std.exception;

void main(){

    int N=5;
    int[] arr1= new int[N];
    for(int i; i<N; i++){ arr1[i]=i;}
    writeln("Main thread, msg= ", arr1);
    auto j=spawn(&fun);
    j.send(thisTid, arr1);   //error!
    enforce(receiveOnly!Tid() == j);

}

void fun(){

    auto msg5= receiveOnly!(Tid, int[])();
    writeln("child thread, msg= ", msg5[1]);
    msg5[0].send(thisTid);

}

On Tuesday, 10 September 2024 at 13:14:05 UTC, Fox wrote:

dlang tries to use the type system to make one be clear about what data is shared between potentially concurrent threads. You need that data to be "shared" before you can send it between threads.

Andy

OK, It works, thanks.

// dlang tries to use the type system to make one be clear about what data is shared between potentially concurrent threads.
// You need that data to be "shared" before you can send it between threads.
// Andy

import std.concurrency;
import std.stdio;

void main(){

    int N=10;
    shared int[] arr1=new int[N];
    for(int i; i<N; i++){arr1[i]=i;}
    writeln("Main thread, msg= ", arr1);
    auto j=spawn(&fun);
    j.send(thisTid, arr1);
    assert(receiveOnly!Tid()==j);

}

void fun(){
auto msg= receiveOnly!(Tid, shared int[])();
writeln("child thread, msg= ", msg[1]);
msg[0].send(thisTid);
}

./a.out
Main thread, msg= [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
child thread, msg= [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]