--- /dev/null	2018-03-12 09:19:30.040007636 +0100
+++ new/src/hotspot/share/runtime/safepointVerifiers.cpp	2018-03-22 17:04:17.892829963 +0100
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 1997, 2017, 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 "runtime/safepointVerifiers.hpp"
+#include "gc/shared/collectedHeap.hpp"
+#include "memory/universe.hpp"
+#include "utilities/debug.hpp"
+
+// Implementation of NoGCVerifier
+
+#ifdef ASSERT
+
+NoGCVerifier::NoGCVerifier(bool verifygc) {
+  _verifygc = verifygc;
+  if (_verifygc) {
+    CollectedHeap* h = Universe::heap();
+    assert(!h->is_gc_active(), "GC active during NoGCVerifier");
+    _old_invocations = h->total_collections();
+  }
+}
+
+
+NoGCVerifier::~NoGCVerifier() {
+  if (_verifygc) {
+    CollectedHeap* h = Universe::heap();
+    assert(!h->is_gc_active(), "GC active during NoGCVerifier");
+    if (_old_invocations != h->total_collections()) {
+      fatal("collection in a NoGCVerifier secured function");
+    }
+  }
+}
+
+PauseNoGCVerifier::PauseNoGCVerifier(NoGCVerifier * ngcv) {
+  _ngcv = ngcv;
+  if (_ngcv->_verifygc) {
+    // if we were verifying, then make sure that nothing is
+    // wrong before we "pause" verification
+    CollectedHeap* h = Universe::heap();
+    assert(!h->is_gc_active(), "GC active during NoGCVerifier");
+    if (_ngcv->_old_invocations != h->total_collections()) {
+      fatal("collection in a NoGCVerifier secured function");
+    }
+  }
+}
+
+
+PauseNoGCVerifier::~PauseNoGCVerifier() {
+  if (_ngcv->_verifygc) {
+    // if we were verifying before, then reenable verification
+    CollectedHeap* h = Universe::heap();
+    assert(!h->is_gc_active(), "GC active during NoGCVerifier");
+    _ngcv->_old_invocations = h->total_collections();
+  }
+}
+
+#endif