| 1 | /* |
| 2 | * Copyright (c) 2017, 2019, 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 | |
| 25 | #ifndef SHARE_GC_SHARED_ACCESSBARRIERSUPPORT_HPP |
| 26 | #define SHARE_GC_SHARED_ACCESSBARRIERSUPPORT_HPP |
| 27 | |
| 28 | #include "memory/allocation.hpp" |
| 29 | #include "oops/access.hpp" |
| 30 | |
| 31 | class AccessBarrierSupport: AllStatic { |
| 32 | private: |
| 33 | static DecoratorSet resolve_unknown_oop_ref_strength(DecoratorSet decorators, oop base, ptrdiff_t offset); |
| 34 | |
| 35 | public: |
| 36 | // Some collectors, like G1, needs to keep referents alive when loading them. |
| 37 | // Therefore, for APIs that accept unknown oop ref strength (e.g. unsafe), |
| 38 | // we need to dynamically find out if a given field is on a java.lang.ref.Reference object. |
| 39 | // and in that case what strength it has. |
| 40 | template<DecoratorSet decorators> |
| 41 | static DecoratorSet resolve_possibly_unknown_oop_ref_strength(oop base, ptrdiff_t offset); |
| 42 | }; |
| 43 | |
| 44 | #endif // SHARE_GC_SHARED_ACCESSBARRIERSUPPORT_HPP |
| 45 | |