import Std::Io::{PrintLine, PrintInt};
import Std::Task::{Task_Wait, TaskHandle};
import Std::Sync::{Mutex, Mutex_New, Mutex_Lock, Mutex_Unlock};

struct Counter {
    value: int;
    mtx: Mutex;
}

func Incrementer(arg: *void) -> *void {
    let c: *Counter = arg as *Counter;
    var i: int = 0;
    while i < 100000 {
        Mutex_Lock(&c.mtx);
        c.value = c.value + 1;
        Mutex_Unlock(&c.mtx);
        i = i + 1;
    }
    return null;
}

func Main() -> int {
    var counter: Counter = Counter { value: 0, mtx: Mutex_New() };

    let a: *void = spawn Incrementer(&counter);
    let b: *void = spawn Incrementer(&counter);

    Task_Wait(TaskHandle { handle: a });
    Task_Wait(TaskHandle { handle: b });

    PrintLine("Counter:");
    PrintInt(counter.value);
    PrintLine("");
    return 0;
}