--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/gtest/gc/shared/test_ptrQueueBufferAllocator.cpp	Thu Nov 15 19:59:10 2018 -0500
@@ -0,0 +1,75 @@
+/*
+ * 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 "gc/shared/ptrQueue.hpp"
+#include "runtime/mutex.hpp"
+#include "unittest.hpp"
+
+// Some basic testing of BufferNode::Allocator.
+TEST_VM(PtrQueueBufferAllocatorTest, test) {
+  Mutex m(Mutex::leaf, "PtrQueueBufferAllocatorTest",
+          false, Mutex::_safepoint_check_never);
+  BufferNode::Allocator allocator(256, &m);
+
+  // Allocate some new nodes for use in testing.
+  BufferNode* nodes[10] = {};
+  const size_t node_count = ARRAY_SIZE(nodes);
+  for (size_t i = 0; i < node_count; ++i) {
+    ASSERT_EQ(0u, allocator.free_count());
+    nodes[i] = allocator.allocate();
+    ASSERT_EQ(NULL, nodes[i]->next());
+  }
+
+  // Release the nodes, adding them to the allocator's free list.
+  for (size_t i = 0; i < node_count; ++i) {
+    ASSERT_EQ(i, allocator.free_count());
+    allocator.release(nodes[i]);
+    if (i == 0) {
+      ASSERT_EQ(NULL, nodes[i]->next());
+    } else {
+      ASSERT_EQ(nodes[i - 1], nodes[i]->next());
+    }
+  }
+
+  // Allocate nodes from the free list.
+  for (size_t i = 0; i < node_count; ++i) {
+    size_t j = node_count - i;
+    ASSERT_EQ(j, allocator.free_count());
+    ASSERT_EQ(nodes[j - 1], allocator.allocate());
+  }
+  ASSERT_EQ(0u, allocator.free_count());
+
+  // Release nodes back to the free list.
+  for (size_t i = 0; i < node_count; ++i) {
+    allocator.release(nodes[i]);
+  }
+  ASSERT_EQ(node_count, allocator.free_count());
+
+  // Destroy some nodes in the free list.
+  // We don't have a way to verify destruction, but we can at
+  // leat verify we don't crash along the way.
+  allocator.reduce_free_list();
+  // destroy allocator.
+}