Re: Help with Concurrency

[Nicholas Wilson via Digitalmars-d-learn]

On Tuesday, 3 November 2015 at 23:16:59 UTC, bertg wrote:
I am having trouble with a simple use of concurrency.
Running the following code I get 3 different tid's, multiple 
"sock in" messages printed, but no receives. I am supposed to 
get a "received!" for each "sock in", but I am getting hung up 
on "receiving...".

Am I misusing or misunderstanding the use of mailboxes?

===

class Connection {
    Reactor reactor;
    WebSocket webSocket;

    this(Reactor r, WebSocket ws)
    {
        reactor = r;
        webSocket = ws;

        messageLoop();
    }

    void messageLoop()
    {
        std.concurrency.Tid tid = std.concurrency.thisTid();
        writeln("tid 1 ~ " ~ 
to!string(std.concurrency.thisTid()));
        writeln("tid 2 ~ " ~ 
to!string(std.concurrency.thisTid()));
        writeln("tid 3 ~ " ~ 
to!string(std.concurrency.thisTid()));

        // deal with websocket messages
        spawn(&handleConnectionWebSocket, tid, cast(shared) 
webSocket);
        // deal with pub/sub
        //spawn();

Try replacing the following loop to have a receive that times out 
or while(true) to while(web socked.connected)
        while (true) {
            writeln("receiving...");
            std.concurrency.receive(
                (string msg) {
                    writeln("conn: received ws message: " ~ 
msg);
                }
            );
            writeln("received!");
        }
    }
}
void handleConnectionWebSocket(std.concurrency.Tid caller, 
shared WebSocket ws)
{
    auto sock = cast(WebSocket) ws;
    while (sock.connected) {
        writeln("sock in");
        auto msgIn = sock.receiveText();
        std.concurrency.send(caller, msgIn);
    }
}