legacy-svn-scala/docs/examples/boundedbuffer.scala

37 lines
895 B
Scala

package examples;
object boundedbuffer {
import concurrent.ops._;
class BoundedBuffer[a](N: Int) {
var in, out, n = 0;
val elems = new Array[a](N);
def await(cond: => Boolean) = while (!cond) { wait() }
def put(x: a) = synchronized {
await (n < N);
elems(in) = x; in = (in + 1) % N; n = n + 1;
if (n == 1) notifyAll();
}
def get: a = synchronized {
await (n != 0);
val x = elems(out); out = (out + 1) % N ; n = n - 1;
if (n == N - 1) notifyAll();
x
}
}
def main(args: Array[String]) = {
val buf = new BoundedBuffer[String](10);
var cnt = 0;
def produceString = { cnt = cnt + 1; cnt.toString() }
def consumeString(ss: String) = System.out.println(ss);
spawn { while (true) { val ssss = produceString; buf.put(ssss) } }
spawn { while (true) { val s = buf.get; consumeString(s) } }
}
}