From 25a98964b5109aa55b71a8a26886c59903193548 Mon Sep 17 00:00:00 2001
From: Martin Odersky <odersky@gmail.com>
Date: Thu, 6 Oct 2005 13:14:33 +0000
Subject: *** empty log message ***

---
 test-nsc/files/pos/MailBox.scala | 83 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100755 test-nsc/files/pos/MailBox.scala

(limited to 'test-nsc/files/pos/MailBox.scala')

diff --git a/test-nsc/files/pos/MailBox.scala b/test-nsc/files/pos/MailBox.scala
new file mode 100755
index 0000000000..b1ea818f60
--- /dev/null
+++ b/test-nsc/files/pos/MailBox.scala
@@ -0,0 +1,83 @@
+package test;
+
+import scala.concurrent._;
+
+class MailBox {
+  private class LinkedList[a] {
+    var elem: a = _;
+    var next: LinkedList[a] = null;
+  }
+
+  private def insert[a](l: LinkedList[a], x: a): LinkedList[a] = {
+    l.next = new LinkedList[a];
+    l.next.elem = x;
+    l.next.next = l.next;
+    l
+  }
+
+  private abstract class Receiver {
+    def isDefined(msg: Any): boolean;
+    var msg: Any = null;
+  }
+
+  private val sent = new LinkedList[Any];
+  private var lastSent = sent;
+  private val receivers = new LinkedList[Receiver];
+  private var lastReceiver = receivers;
+
+  def send(msg: Any): unit = synchronized {
+    var r = receivers;
+    var r1 = r.next;
+    while (r1 != null && !r1.elem.isDefined(msg)) {
+      r = r1; r1 = r1.next;
+    }
+    if (r1 != null) {
+      r.next = r1.next; r1.elem.msg = msg; r1.elem.notify();
+    } else {
+      lastSent = insert(lastSent, msg);
+    }
+  }
+
+  def receive[a](f: PartialFunction[Any, a]): a = {
+    val msg: Any = synchronized {
+      var s = sent;
+      var s1 = s.next;
+      while (s1 != null && !f.isDefinedAt(s1.elem)) {
+        s = s1; s1 = s1.next
+      }
+      if (s1 != null) {
+        s.next = s1.next; s1.elem
+      } else {
+	val r = insert(lastReceiver, new Receiver {
+          def isDefined(msg: Any) = f.isDefinedAt(msg);
+        });
+	lastReceiver = r;
+        r.elem.wait();
+        r.elem.msg
+      }
+    }
+    f(msg)
+  }
+
+  def receiveWithin[a](msec: long)(f: PartialFunction[Any, a]): a = {
+    val msg: Any = synchronized {
+      var s = sent;
+      var s1 = s.next;
+      while (s1 != null && !f.isDefinedAt(s1.elem)) {
+        s = s1; s1 = s1.next ;
+      }
+      if (s1 != null) {
+        s.next = s1.next; s1.elem
+      } else {
+        val r = insert(lastReceiver, new Receiver {
+            def isDefined(msg: Any) = f.isDefinedAt(msg);
+        });
+        lastReceiver = r;
+        r.elem.wait(msec);
+        if (r.elem.msg == null) r.elem.msg = TIMEOUT;
+        r.elem.msg
+      }
+    }
+    f(msg)
+  }
+}
-- 
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