--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jvmci/jniAccessMark.inline.hpp	Wed May 01 12:31:29 2019 -0700
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2019, 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.
+ *
+ */
+
+#ifndef SHARE_JVMCI_JNIACCESSMARK_INLINE_HPP
+#define SHARE_JVMCI_JNIACCESSMARK_INLINE_HPP
+
+#include "jvmci/jvmciEnv.hpp"
+#include "runtime/interfaceSupport.inline.hpp"
+
+// Wrapper for a JNI call into the JVMCI shared library.
+// This performs a ThreadToNativeFromVM transition so that the VM
+// will not be blocked if the call takes a long time (e.g., due
+// to a GC in the shared library).
+class JNIAccessMark : public StackObj {
+ private:
+  ThreadToNativeFromVM ttnfv;
+  HandleMark hm;
+  JNIEnv* _env;
+ public:
+  inline JNIAccessMark(JVMCIEnv* jvmci_env) :
+    ttnfv(JavaThread::current()), hm(JavaThread::current()) {
+    _env = jvmci_env->_env;
+  }
+  JNIEnv* env() const { return _env; }
+  JNIEnv* operator () () const { return _env; }
+};
+
+#endif // SHARE_JVMCI_JNIACCESSMARK_INLINE_HPP