--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.ruby.nodes/src/com/oracle/truffle/ruby/nodes/core/FiberNodes.java	Tue Jan 07 18:53:04 2014 +0100
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2013 Oracle and/or its affiliates. All rights reserved. This
+ * code is released under a tri EPL/GPL/LGPL license. You can use it,
+ * redistribute it and/or modify it under the terms of the:
+ *
+ * Eclipse Public License version 1.0
+ * GNU General Public License version 2
+ * GNU Lesser General Public License version 2.1
+ */
+package com.oracle.truffle.ruby.nodes.core;
+
+import com.oracle.truffle.api.*;
+import com.oracle.truffle.api.dsl.*;
+import com.oracle.truffle.ruby.runtime.*;
+import com.oracle.truffle.ruby.runtime.core.*;
+
+@CoreClass(name = "Fiber")
+public abstract class FiberNodes {
+
+    @CoreMethod(names = "resume", isSplatted = true)
+    public abstract static class ResumeNode extends CoreMethodNode {
+
+        public ResumeNode(RubyContext context, SourceSection sourceSection) {
+            super(context, sourceSection);
+        }
+
+        public ResumeNode(ResumeNode prev) {
+            super(prev);
+        }
+
+        @Specialization
+        public Object resume(RubyFiber fiberBeingResumed, Object[] args) {
+            final RubyFiber sendingFiber = getContext().getFiberManager().getCurrentFiber();
+
+            fiberBeingResumed.resume(sendingFiber, args);
+
+            return sendingFiber.waitForResume();
+        }
+
+    }
+
+    @CoreMethod(names = "initialize", needsBlock = true, maxArgs = 0)
+    public abstract static class InitializeNode extends CoreMethodNode {
+
+        public InitializeNode(RubyContext context, SourceSection sourceSection) {
+            super(context, sourceSection);
+        }
+
+        public InitializeNode(InitializeNode prev) {
+            super(prev);
+        }
+
+        @Specialization
+        public NilPlaceholder initialize(RubyFiber fiber, RubyProc block) {
+            fiber.initialize(block);
+            return NilPlaceholder.INSTANCE;
+        }
+
+    }
+
+    @CoreMethod(names = "yield", isModuleMethod = true, needsSelf = false, isSplatted = true)
+    public abstract static class YieldNode extends CoreMethodNode {
+
+        public YieldNode(RubyContext context, SourceSection sourceSection) {
+            super(context, sourceSection);
+        }
+
+        public YieldNode(YieldNode prev) {
+            super(prev);
+        }
+
+        @Specialization
+        public Object yield(Object[] args) {
+            final RubyFiber yieldingFiber = getContext().getFiberManager().getCurrentFiber();
+            final RubyFiber fiberYieldedTo = yieldingFiber.lastResumedByFiber;
+
+            fiberYieldedTo.resume(yieldingFiber, args);
+
+            return yieldingFiber.waitForResume();
+        }
+
+    }
+
+}