| 1 | /* |
| 2 | * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 12 | * version 2 for more details (a copy is included in the LICENSE file that |
| 13 | * accompanied this code). |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License version |
| 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 18 | * |
| 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| 20 | * or visit www.oracle.com if you need additional information or have any |
| 21 | * questions. |
| 22 | */ |
| 23 | |
| 24 | #include "precompiled.hpp" |
| 25 | #include "runtime/objectMonitor.hpp" |
| 26 | #include "runtime/vm_version.hpp" |
| 27 | #include "unittest.hpp" |
| 28 | |
| 29 | TEST_VM(ObjectMonitor, sanity) { |
| 30 | |
| 31 | EXPECT_EQ(0, ObjectMonitor::header_offset_in_bytes()) << "Offset for _header must be zero." ; |
| 32 | |
| 33 | uint cache_line_size = VM_Version::L1_data_cache_line_size(); |
| 34 | |
| 35 | if (cache_line_size != 0) { |
| 36 | // We were able to determine the L1 data cache line size so |
| 37 | // do some cache line specific sanity checks |
| 38 | EXPECT_EQ((size_t) 0, sizeof (PaddedEnd<ObjectMonitor>) % cache_line_size) |
| 39 | << "PaddedEnd<ObjectMonitor> size is not a " |
| 40 | << "multiple of a cache line which permits false sharing. " |
| 41 | << "sizeof(PaddedEnd<ObjectMonitor>) = " |
| 42 | << sizeof (PaddedEnd<ObjectMonitor>) |
| 43 | << "; cache_line_size = " << cache_line_size; |
| 44 | |
| 45 | EXPECT_GE((size_t) ObjectMonitor::owner_offset_in_bytes(), cache_line_size) |
| 46 | << "the _header and _owner fields are closer " |
| 47 | << "than a cache line which permits false sharing." ; |
| 48 | } |
| 49 | } |
| 50 | |