--- /dev/null	2020-01-17 11:46:19.065201212 +0100
+++ new/test/hotspot/jtreg/gc/shenandoah/jni/libTestJNICritical.c	2020-01-17 17:11:25.504126325 +0100
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2016, 2017, Red Hat, Inc. All rights reserved.
+ *
+ * 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 <jni.h>
+#include <string.h>
+
+JNIEXPORT void JNICALL
+Java_TestJNICritical_copyAtoB(JNIEnv *env, jclass unused, jintArray a, jintArray b) {
+  jint len = (*env)->GetArrayLength(env, a);
+  jint* aa = (*env)->GetPrimitiveArrayCritical(env, a, 0);
+  jint* bb = (*env)->GetPrimitiveArrayCritical(env, b, 0);
+  memcpy(bb, aa, len * sizeof(jint));
+  (*env)->ReleasePrimitiveArrayCritical(env, b, bb, 0);
+  (*env)->ReleasePrimitiveArrayCritical(env, a, aa, 0);
+}