--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/z/zBarrierSetNMethod.cpp	Tue Dec 11 11:08:39 2018 +0100
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#include "precompiled.hpp"
+#include "code/nmethod.hpp"
+#include "gc/z/zBarrierSetNMethod.hpp"
+#include "gc/z/zGlobals.hpp"
+#include "gc/z/zLock.inline.hpp"
+#include "gc/z/zOopClosures.hpp"
+#include "gc/z/zNMethodTable.hpp"
+#include "gc/z/zThreadLocalData.hpp"
+#include "logging/log.hpp"
+
+bool ZBarrierSetNMethod::nmethod_entry_barrier(nmethod* nm) {
+  ZLocker<ZReentrantLock> locker(ZNMethodTable::lock_for_nmethod(nm));
+  log_trace(nmethod, barrier)("Entered critical zone for %p", nm);
+
+  if (!is_armed(nm)) {
+    // Some other thread got here first and healed the oops
+    // and disarmed the nmethod.
+    return true;
+  }
+
+  if (nm->is_unloading()) {
+    // We can end up calling nmethods that are unloading
+    // since we clear compiled ICs lazily. Returning false
+    // will re-resovle the call and update the compiled IC.
+    return false;
+  }
+
+  // Heal oops and disarm
+  ZNMethodOopClosure cl;
+  nm->oops_do(&cl);
+  nm->fix_oop_relocations();
+
+  OrderAccess::release();
+
+  disarm(nm);
+
+  return true;
+}
+
+int ZBarrierSetNMethod::disarmed_value() const {
+  // We override the default BarrierSetNMethod::disarmed_value() since
+  // this can be called by GC threads, which doesn't keep an up to date
+  // address_bad_mask.
+  const uintptr_t disarmed_addr = ((uintptr_t)&ZAddressBadMask) + ZNMethodDisarmedOffset;
+  return *((int*)disarmed_addr);
+}
+
+ByteSize ZBarrierSetNMethod::thread_disarmed_offset() const {
+  return ZThreadLocalData::nmethod_disarmed_offset();
+}