--- a/src/hotspot/share/runtime/objectMonitor.cpp	Fri Jul 27 14:20:07 2018 +0530
+++ b/src/hotspot/share/runtime/objectMonitor.cpp	Fri Jul 27 16:29:36 2018 -0400
@@ -2354,10 +2354,6 @@
   SETKNOB(FastHSSEC);
   #undef SETKNOB
 
-  if (Knob_Verbose) {
-    sanity_checks();
-  }
-
   if (os::is_MP()) {
     BackOffMask = (1 << Knob_SpinBackOff) - 1;
     if (Knob_ReportSettings) {
@@ -2376,70 +2372,3 @@
   InitDone = 1;
 }
 
-void ObjectMonitor::sanity_checks() {
-  int error_cnt = 0;
-  int warning_cnt = 0;
-  bool verbose = Knob_Verbose != 0 NOT_PRODUCT(|| VerboseInternalVMTests);
-
-  if (verbose) {
-    tty->print_cr("INFO: sizeof(ObjectMonitor)=" SIZE_FORMAT,
-                  sizeof(ObjectMonitor));
-    tty->print_cr("INFO: sizeof(PaddedEnd<ObjectMonitor>)=" SIZE_FORMAT,
-                  sizeof(PaddedEnd<ObjectMonitor>));
-  }
-
-  uint cache_line_size = VM_Version::L1_data_cache_line_size();
-  if (verbose) {
-    tty->print_cr("INFO: L1_data_cache_line_size=%u", cache_line_size);
-  }
-
-  ObjectMonitor dummy;
-  u_char *addr_begin  = (u_char*)&dummy;
-  u_char *addr_header = (u_char*)&dummy._header;
-  u_char *addr_owner  = (u_char*)&dummy._owner;
-
-  uint offset_header = (uint)(addr_header - addr_begin);
-  if (verbose) tty->print_cr("INFO: offset(_header)=%u", offset_header);
-
-  uint offset_owner = (uint)(addr_owner - addr_begin);
-  if (verbose) tty->print_cr("INFO: offset(_owner)=%u", offset_owner);
-
-  if ((uint)(addr_header - addr_begin) != 0) {
-    tty->print_cr("ERROR: offset(_header) must be zero (0).");
-    error_cnt++;
-  }
-
-  if (cache_line_size != 0) {
-    // We were able to determine the L1 data cache line size so
-    // do some cache line specific sanity checks
-
-    if ((offset_owner - offset_header) < cache_line_size) {
-      tty->print_cr("WARNING: the _header and _owner fields are closer "
-                    "than a cache line which permits false sharing.");
-      warning_cnt++;
-    }
-
-    if ((sizeof(PaddedEnd<ObjectMonitor>) % cache_line_size) != 0) {
-      tty->print_cr("WARNING: PaddedEnd<ObjectMonitor> size is not a "
-                    "multiple of a cache line which permits false sharing.");
-      warning_cnt++;
-    }
-  }
-
-  ObjectSynchronizer::sanity_checks(verbose, cache_line_size, &error_cnt,
-                                    &warning_cnt);
-
-  if (verbose || error_cnt != 0 || warning_cnt != 0) {
-    tty->print_cr("INFO: error_cnt=%d", error_cnt);
-    tty->print_cr("INFO: warning_cnt=%d", warning_cnt);
-  }
-
-  guarantee(error_cnt == 0,
-            "Fatal error(s) found in ObjectMonitor::sanity_checks()");
-}
-
-#ifndef PRODUCT
-void ObjectMonitor_test() {
-  ObjectMonitor::sanity_checks();
-}
-#endif

--- a/src/hotspot/share/runtime/objectMonitor.hpp	Fri Jul 27 14:20:07 2018 +0530
+++ b/src/hotspot/share/runtime/objectMonitor.hpp	Fri Jul 27 16:29:36 2018 -0400
@@ -103,11 +103,11 @@
 //   coherency misses. There is no single optimal layout for both
 //   single-threaded and multi-threaded environments.
 //
-// - See ObjectMonitor::sanity_checks() for how critical restrictions are
-//   enforced and advisory recommendations are reported.
+// - See TEST_VM(ObjectMonitor, sanity) gtest for how critical restrictions are
+//   enforced.
 // - Adjacent ObjectMonitors should be separated by enough space to avoid
 //   false sharing. This is handled by the ObjectMonitor allocation code
-//   in synchronizer.cpp. Also see ObjectSynchronizer::sanity_checks().
+//   in synchronizer.cpp. Also see TEST_VM(SynchronizerTest, sanity) gtest.
 //
 // Futures notes:
 //   - Separating _owner from the <remaining_fields> by enough space to
@@ -294,8 +294,6 @@
   bool      check(TRAPS);       // true if the thread owns the monitor.
   void      check_slow(TRAPS);
   void      clear();
-  static void sanity_checks();  // public for -XX:+ExecuteInternalVMTests
-                                // in PRODUCT for -XX:SyncKnobs=Verbose=1
 
   void      enter(TRAPS);
   void      exit(bool not_suspended, TRAPS);

--- a/src/hotspot/share/runtime/synchronizer.cpp	Fri Jul 27 14:20:07 2018 +0530
+++ b/src/hotspot/share/runtime/synchronizer.cpp	Fri Jul 27 16:29:36 2018 -0400
@@ -1906,52 +1906,20 @@
 //------------------------------------------------------------------------------
 // Debugging code
 
-void ObjectSynchronizer::sanity_checks(const bool verbose,
-                                       const uint cache_line_size,
-                                       int *error_cnt_ptr,
-                                       int *warning_cnt_ptr) {
-  u_char *addr_begin      = (u_char*)&GVars;
-  u_char *addr_stwRandom  = (u_char*)&GVars.stwRandom;
-  u_char *addr_hcSequence = (u_char*)&GVars.hcSequence;
-
-  if (verbose) {
-    tty->print_cr("INFO: sizeof(SharedGlobals)=" SIZE_FORMAT,
-                  sizeof(SharedGlobals));
-  }
-
-  uint offset_stwRandom = (uint)(addr_stwRandom - addr_begin);
-  if (verbose) tty->print_cr("INFO: offset(stwRandom)=%u", offset_stwRandom);
-
-  uint offset_hcSequence = (uint)(addr_hcSequence - addr_begin);
-  if (verbose) {
-    tty->print_cr("INFO: offset(_hcSequence)=%u", offset_hcSequence);
-  }
+u_char* ObjectSynchronizer::get_gvars_addr() {
+  return (u_char*)&GVars;
+}
 
-  if (cache_line_size != 0) {
-    // We were able to determine the L1 data cache line size so
-    // do some cache line specific sanity checks
-
-    if (offset_stwRandom < cache_line_size) {
-      tty->print_cr("WARNING: the SharedGlobals.stwRandom field is closer "
-                    "to the struct beginning than a cache line which permits "
-                    "false sharing.");
-      (*warning_cnt_ptr)++;
-    }
+u_char* ObjectSynchronizer::get_gvars_hcSequence_addr() {
+  return (u_char*)&GVars.hcSequence;
+}
 
-    if ((offset_hcSequence - offset_stwRandom) < cache_line_size) {
-      tty->print_cr("WARNING: the SharedGlobals.stwRandom and "
-                    "SharedGlobals.hcSequence fields are closer than a cache "
-                    "line which permits false sharing.");
-      (*warning_cnt_ptr)++;
-    }
+size_t ObjectSynchronizer::get_gvars_size() {
+  return sizeof(SharedGlobals);
+}
 
-    if ((sizeof(SharedGlobals) - offset_hcSequence) < cache_line_size) {
-      tty->print_cr("WARNING: the SharedGlobals.hcSequence field is closer "
-                    "to the struct end than a cache line which permits false "
-                    "sharing.");
-      (*warning_cnt_ptr)++;
-    }
-  }
+u_char* ObjectSynchronizer::get_gvars_stwRandom_addr() {
+  return (u_char*)&GVars.stwRandom;
 }
 
 #ifndef PRODUCT

--- a/src/hotspot/share/runtime/synchronizer.hpp	Fri Jul 27 14:20:07 2018 +0530
+++ b/src/hotspot/share/runtime/synchronizer.hpp	Fri Jul 27 16:29:36 2018 -0400
@@ -153,12 +153,11 @@
   static void thread_local_used_oops_do(Thread* thread, OopClosure* f);
 
   // debugging
-  static void sanity_checks(const bool verbose,
-                            const unsigned int cache_line_size,
-                            int *error_cnt_ptr, int *warning_cnt_ptr);
   static int  verify_objmon_isinpool(ObjectMonitor *addr) PRODUCT_RETURN0;
 
  private:
+  friend class SynchronizerTest;
+
   enum { _BLOCKSIZE = 128 };
   // global list of blocks of monitors
   static PaddedEnd<ObjectMonitor> * volatile gBlockList;
@@ -177,6 +176,11 @@
   // Process oops in monitors on the given list
   static void list_oops_do(ObjectMonitor* list, OopClosure* f);
 
+  // Support for SynchronizerTest access to GVars fields:
+  static u_char* get_gvars_addr();
+  static u_char* get_gvars_hcSequence_addr();
+  static size_t get_gvars_size();
+  static u_char* get_gvars_stwRandom_addr();
 };
 
 // ObjectLocker enforced balanced locking and can never thrown an

--- a/src/hotspot/share/utilities/internalVMTests.cpp	Fri Jul 27 14:20:07 2018 +0530
+++ b/src/hotspot/share/utilities/internalVMTests.cpp	Fri Jul 27 16:29:36 2018 -0400
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 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
@@ -47,7 +47,6 @@
   run_unit_test(TestVirtualSpace_test);
   run_unit_test(TestMetaspaceUtils_test);
   run_unit_test(GCTimer_test);
-  run_unit_test(ObjectMonitor_test);
   // These tests require the "C" locale to correctly parse decimal values
   const char* orig_locale = setlocale(LC_NUMERIC, NULL);
   setlocale(LC_NUMERIC, "C");

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/gtest/runtime/test_objectMonitor.cpp	Fri Jul 27 16:29:36 2018 -0400
@@ -0,0 +1,49 @@
+/*
+ * 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 "runtime/objectMonitor.hpp"
+#include "runtime/vm_version.hpp"
+#include "unittest.hpp"
+
+TEST_VM(ObjectMonitor, sanity) {
+
+ EXPECT_EQ(0, ObjectMonitor::header_offset_in_bytes()) << "Offset for _header must be zero.";
+
+ uint cache_line_size = VM_Version::L1_data_cache_line_size();
+
+ if (cache_line_size != 0) {
+   // We were able to determine the L1 data cache line size so
+   // do some cache line specific sanity checks
+   EXPECT_EQ((size_t) 0, sizeof (PaddedEnd<ObjectMonitor>) % cache_line_size)
+        << "PaddedEnd<ObjectMonitor> size is not a "
+        << "multiple of a cache line which permits false sharing. "
+        << "sizeof(PaddedEnd<ObjectMonitor>) = "
+        << sizeof (PaddedEnd<ObjectMonitor>)
+        << "; cache_line_size = " << cache_line_size;
+
+   EXPECT_GE((size_t) ObjectMonitor::owner_offset_in_bytes(), cache_line_size)
+        << "the _header and _owner fields are closer "
+        << "than a cache line which permits false sharing.";
+  }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/gtest/runtime/test_synchronizer.cpp	Fri Jul 27 16:29:36 2018 -0400
@@ -0,0 +1,69 @@
+/*
+ * 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 "memory/allocation.hpp"
+#include "runtime/synchronizer.hpp"
+#include "runtime/vm_version.hpp"
+#include "unittest.hpp"
+
+class SynchronizerTest : public ::testing::Test {
+  public:
+    static u_char* get_gvars_addr() { return ObjectSynchronizer::get_gvars_addr(); }
+    static u_char* get_gvars_hcSequence_addr() { return ObjectSynchronizer::get_gvars_hcSequence_addr(); }
+    static size_t get_gvars_size() { return ObjectSynchronizer::get_gvars_size(); }
+    static u_char* get_gvars_stwRandom_addr() { return ObjectSynchronizer::get_gvars_stwRandom_addr(); }
+};
+
+TEST_VM(SynchronizerTest, sanity) {
+  uint cache_line_size = VM_Version::L1_data_cache_line_size();
+  if (cache_line_size != 0) {
+    // We were able to determine the L1 data cache line size so
+    // do some cache line specific sanity checks
+
+    u_char *addr_begin = SynchronizerTest::get_gvars_addr();
+    u_char *addr_stwRandom = SynchronizerTest::get_gvars_stwRandom_addr();
+    u_char *addr_hcSequence = SynchronizerTest::get_gvars_hcSequence_addr();
+    size_t gvars_size = SynchronizerTest::get_gvars_size();
+
+    uint offset_stwRandom = (uint) (addr_stwRandom - addr_begin);
+    uint offset_hcSequence = (uint) (addr_hcSequence - addr_begin);
+    uint offset_hcSequence_stwRandom = offset_hcSequence - offset_stwRandom;
+    uint offset_hcSequence_struct_end = (uint) gvars_size - offset_hcSequence;
+
+    EXPECT_GE(offset_stwRandom, cache_line_size)
+            << "the SharedGlobals.stwRandom field is closer "
+            << "to the struct beginning than a cache line which permits "
+            << "false sharing.";
+
+    EXPECT_GE(offset_hcSequence_stwRandom, cache_line_size)
+            << "the SharedGlobals.stwRandom and "
+            << "SharedGlobals.hcSequence fields are closer than a cache "
+            << "line which permits false sharing.";
+
+    EXPECT_GE(offset_hcSequence_struct_end, cache_line_size)
+            << "the SharedGlobals.hcSequence field is closer "
+            << "to the struct end than a cache line which permits false "
+            << "sharing.";
+  }
+}