/*

 * 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

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 */

#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.";

  }

}