D并行与旋转器

原文

import std.stdio;
import std.concurrency;
import core.thread;

void main() {
  spawnLinked(&spinner, 100.msecs);
  enum n = 45;
  const fibN = fib(n); // slow
  writefln!"\rFibonacci(%d) = %d"(n, fibN);
}

void spinner(const(Duration) delay) {
  for (;;) {
    foreach (r; `-\|/`) {
      writef!"\r%c"(r);
      stdout.flush();
      bool done;
      receiveTimeout(delay,
                     (OwnerTerminated msg) {
                       done = true;
                     });
      if (done) {
        return;
      }
    }
  }
}

auto fib(int x) {
  if (x < 2) {
    return x;
  }
  return fib(x-1) + fib(x-2);
}

D并行Fib.检查返回值:

if (receiveTimeout(delay, (OwnerTerminated msg) {})) {
        return;
      }