--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/gtest/oops/test_markWord.cpp	Mon Oct 28 11:21:43 2019 -0400
@@ -0,0 +1,150 @@
+/*
+ * 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.
+ */
+
+#include "precompiled.hpp"
+#include "classfile/systemDictionary.hpp"
+#include "memory/resourceArea.hpp"
+#include "memory/universe.hpp"
+#include "oops/oop.inline.hpp"
+#include "runtime/atomic.hpp"
+#include "runtime/biasedLocking.hpp"
+#include "runtime/interfaceSupport.inline.hpp"
+#include "runtime/orderAccess.hpp"
+#include "runtime/os.hpp"
+#include "runtime/synchronizer.hpp"
+#include "runtime/semaphore.inline.hpp"
+#include "threadHelper.inline.hpp"
+#include "unittest.hpp"
+#include "utilities/globalDefinitions.hpp"
+#include "utilities/ostream.hpp"
+
+// The test doesn't work for PRODUCT because it needs WizardMode
+#ifndef PRODUCT
+static bool test_pattern(stringStream* st, const char* pattern) {
+  return (strstr(st->as_string(), pattern) != NULL);
+}
+
+static void assert_test_pattern(Handle object, const char* pattern) {
+  stringStream st;
+  object->print_on(&st);
+  ASSERT_TRUE(test_pattern(&st, pattern)) << pattern << " not in " << st.as_string();
+}
+
+static void assert_not_test_pattern(Handle object, const char* pattern) {
+  stringStream st;
+  object->print_on(&st);
+  ASSERT_FALSE(test_pattern(&st, pattern)) << pattern << " found in " << st.as_string();
+}
+
+class LockerThread : public JavaTestThread {
+  oop _obj;
+  public:
+  LockerThread(Semaphore* post, oop obj) : JavaTestThread(post), _obj(obj) {}
+  virtual ~LockerThread() {}
+
+  void main_run() {
+    Thread* THREAD = Thread::current();
+    HandleMark hm(THREAD);
+    Handle h_obj(THREAD, _obj);
+    ResourceMark rm(THREAD);
+
+    // Wait gets the lock inflated.
+    // The object will stay locked for the context of 'ol' so the lock will
+    // still be inflated after the notify_all() call. Deflation can't happen
+    // while an ObjectMonitor is "busy" and being locked is the most "busy"
+    // state we have...
+    ObjectLocker ol(h_obj, THREAD);
+    ol.notify_all(THREAD);
+    assert_test_pattern(h_obj, "monitor");
+  }
+};
+
+
+TEST_VM(markWord, printing) {
+  JavaThread* THREAD = JavaThread::current();
+  ThreadInVMfromNative invm(THREAD);
+  ResourceMark rm(THREAD);
+
+  if (!UseBiasedLocking || !BiasedLocking::enabled()) {
+    // Can't test this with biased locking disabled.
+    return;
+  }
+
+  oop obj = SystemDictionary::Byte_klass()->allocate_instance(THREAD);
+
+  FlagSetting fs(WizardMode, true);
+
+  HandleMark hm(THREAD);
+  Handle h_obj(THREAD, obj);
+
+  // Biased locking is initially enabled for this java.lang.Byte object.
+  assert_test_pattern(h_obj, "is_biased");
+
+  // Lock using biased locking.
+  BasicObjectLock lock;
+  lock.set_obj(obj);
+  markWord prototype_header = obj->klass()->prototype_header();
+  markWord mark = obj->mark();
+  markWord biased_mark = markWord::encode((JavaThread*) THREAD, mark.age(), prototype_header.bias_epoch());
+  obj->set_mark(biased_mark);
+  // Look for the biased_locker in markWord, not prototype_header.
+#ifdef _LP64
+  assert_not_test_pattern(h_obj, "mark(is_biased biased_locker=0x0000000000000000");
+#else
+  assert_not_test_pattern(h_obj, "mark(is_biased biased_locker=0x00000000");
+#endif
+
+  // Same thread tries to lock it again.
+  {
+    ObjectLocker ol(h_obj, THREAD);
+    assert_test_pattern(h_obj, "locked");
+  }
+
+  // This is no longer biased, because ObjectLocker revokes the bias.
+  assert_test_pattern(h_obj, "is_neutral no_hash");
+
+  // Wait gets the lock inflated.
+  {
+    ObjectLocker ol(h_obj, THREAD);
+
+    Semaphore done(0);
+    LockerThread* st;
+    st = new LockerThread(&done, h_obj());
+    st->doit();
+
+    ol.wait(THREAD);
+    assert_test_pattern(h_obj, "monitor");
+    done.wait_with_safepoint_check(THREAD);  // wait till the thread is done.
+  }
+
+  // Make the object older. Not all GCs use this field.
+  Universe::heap()->collect(GCCause::_java_lang_system_gc);
+  if (UseParallelGC) {
+    assert_test_pattern(h_obj, "is_neutral no_hash age 1");
+  }
+
+  // Hash the object then print it.
+  intx hash = h_obj->identity_hash();
+  assert_test_pattern(h_obj, "is_neutral hash=0x");
+}
+#endif // PRODUCT