1 files changed, 0 insertions, 72 deletions
diff --git a/docs/examples/pilib/semaphore.scala b/docs/examples/pilib/semaphore.scala
deleted file mode 100644
index 951c90e8d4..0000000000
--- a/docs/examples/pilib/semaphore.scala
+++ /dev/null
@@ -1,72 +0,0 @@
-package examples.pilib
-
-import scala.concurrent.pilib._
-
-/** Solution of exercise session 6 (first question). */
-object semaphore {
-
-  class Signal extends Chan[Unit] {
-    def send = write(())
-    def receive = read
-  }
-
-  /** Interface. */
-  trait Semaphore {
-    def get: Unit
-    def release: Unit
-  }
-
-  /** First implementation. */
-  class Sem1 extends Semaphore {
-
-    private val g = new Signal
-    private val r = new Signal
-
-    def get: Unit = g.send
-    def release: Unit = r.send
-
-    private def Sched: Unit = choice (
-      g * (x => { r.receive; Sched }),
-      r * (x => Sched)
-    )
-    spawn< Sched >
-  }
-
-  /** Second implementation. */
-  class Sem2 extends Semaphore {
-
-    private val a = new Signal
-    private val na = new Signal
-
-    def get { a.receive; spawn< na.send > }
-    def release: Unit = choice (
-      a * (x => spawn< a.send >),
-      na * (x => spawn< a.send >)
-    )
-    spawn< a.send >
-  }
-
-  /** Test program. */
-  def main(args: Array[String]) {
-    val random = new util.Random()
-    val sem = new Sem2
-    def mutex(p: => Unit) { sem.get; p; sem.release }
-
-    spawn< {
-      Thread.sleep(1 + random.nextInt(100));
-      mutex( {
-        println("a1");
-        Thread.sleep(1 + random.nextInt(100));
-        println("a2")
-      } )
-    } | {
-      Thread.sleep(1 + random.nextInt(100));
-      mutex( {
-        println("b1");
-        Thread.sleep(1 + random.nextInt(100));
-        println("b2")
-      } ) 
-    } >;
-  }
-}
-