On 04/08/2016 02:42 PM, Dicebot wrote:
>> Thanks Dicebot. I don't think the included
>> std.concurrency.FiberScheduler has support for message passing because
>> FiberScheduler.spawn does not return a Tid. If so, I don't see how
>> it's possible to send messages between fibers.
>>
>> Ali
>
> Looks like a (funny) oversight.
Sorry, I misled you. :)
> Note that you get it for get fiber via
>
https://github.com/D-Programming-Language/phobos/blob/master/std/concurrency.d#L1337
> (and FiberScheduler specifically extends Fiber to add ThreadInfo to it)
> but there is no clear way to pass that info to spawn host. I have a
> feeling that if that code is patched to simply provide Tid, message
> passing will just magically work. Needs to be checked though.
It turns out, instead of calling scheduler.spawn() directly, the program
sets the __gshared 'scheduler' variable first and then calls spawn() as
usual, which does return that fiber's Tid:
import std.stdio;
import std.concurrency;
import std.range;
import std.algorithm;
struct Done {
}
void workerTask(int id) {
writefln("workerTask %s started", id);
bool done = false;
while (!done) {
receive(
(int message) {
writefln("workerTask %s received %s", id, message);
ownerTid.send(message * id);
},
(Done message) {
writefln("workerTask %s received Done", id);
done = true;
});
// Seems not to be needed:
// scheduler.yield();
}
writefln("workerTask %s exiting", id);
}
void mainTask() {
enum workerCount = 5;
enum loopCount = 3;
writeln("mainTask started");
auto workers = iota(workerCount)
.map!(id => spawn(&workerTask, id))
.array;
foreach (i; 0 .. loopCount) {
foreach (id, worker; workers) {
worker.send(i);
auto response = receiveOnly!int();
assert(response == i * id);
writefln("mainTask received %s", response);
}
}
writeln("mainTask sending Done messages");
foreach (worker; workers) {
worker.send(Done());
}
writeln("mainTask exiting");
}
void main() {
scheduler = new FiberScheduler;
scheduler.start({
mainTask();
});
}
Ali
