| /* |
| * Copyright (c) 2006, 2012, 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. |
| * |
| */ |
| |
| #ifndef SHARE_VM_OOPS_MARKOOP_INLINE_HPP |
| #define SHARE_VM_OOPS_MARKOOP_INLINE_HPP |
| |
| #include "oops/klass.hpp" |
| #include "oops/markOop.hpp" |
| #include "runtime/globals.hpp" |
| |
| // Should this header be preserved during GC (when biased locking is enabled)? |
| inline bool markOopDesc::must_be_preserved_with_bias(oop obj_containing_mark) const { |
| assert(UseBiasedLocking, "unexpected"); |
| if (has_bias_pattern()) { |
| // Will reset bias at end of collection |
| // Mark words of biased and currently locked objects are preserved separately |
| return false; |
| } |
| markOop prototype_header = prototype_for_object(obj_containing_mark); |
| if (prototype_header->has_bias_pattern()) { |
| // Individual instance which has its bias revoked; must return |
| // true for correctness |
| return true; |
| } |
| return (!is_unlocked() || !has_no_hash()); |
| } |
| |
| // Should this header be preserved during GC? |
| inline bool markOopDesc::must_be_preserved(oop obj_containing_mark) const { |
| if (!UseBiasedLocking) |
| return (!is_unlocked() || !has_no_hash()); |
| return must_be_preserved_with_bias(obj_containing_mark); |
| } |
| |
| // Should this header be preserved in the case of a promotion failure |
| // during scavenge (when biased locking is enabled)? |
| inline bool markOopDesc::must_be_preserved_with_bias_for_promotion_failure(oop obj_containing_mark) const { |
| assert(UseBiasedLocking, "unexpected"); |
| // We don't explicitly save off the mark words of biased and |
| // currently-locked objects during scavenges, so if during a |
| // promotion failure we encounter either a biased mark word or a |
| // klass which still has a biasable prototype header, we have to |
| // preserve the mark word. This results in oversaving, but promotion |
| // failures are rare, and this avoids adding more complex logic to |
| // the scavengers to call new variants of |
| // BiasedLocking::preserve_marks() / restore_marks() in the middle |
| // of a scavenge when a promotion failure has first been detected. |
| if (has_bias_pattern() || |
| prototype_for_object(obj_containing_mark)->has_bias_pattern()) { |
| return true; |
| } |
| return (!is_unlocked() || !has_no_hash()); |
| } |
| |
| // Should this header be preserved in the case of a promotion failure |
| // during scavenge? |
| inline bool markOopDesc::must_be_preserved_for_promotion_failure(oop obj_containing_mark) const { |
| if (!UseBiasedLocking) |
| return (!is_unlocked() || !has_no_hash()); |
| return must_be_preserved_with_bias_for_promotion_failure(obj_containing_mark); |
| } |
| |
| |
| // Same as must_be_preserved_with_bias_for_promotion_failure() except that |
| // it takes a Klass* argument, instead of the object of which this is the mark word. |
| inline bool markOopDesc::must_be_preserved_with_bias_for_cms_scavenge(Klass* klass_of_obj_containing_mark) const { |
| assert(UseBiasedLocking, "unexpected"); |
| // CMS scavenges preserve mark words in similar fashion to promotion failures; see above |
| if (has_bias_pattern() || |
| klass_of_obj_containing_mark->prototype_header()->has_bias_pattern()) { |
| return true; |
| } |
| return (!is_unlocked() || !has_no_hash()); |
| } |
| |
| // Same as must_be_preserved_for_promotion_failure() except that |
| // it takes a Klass* argument, instead of the object of which this is the mark word. |
| inline bool markOopDesc::must_be_preserved_for_cms_scavenge(Klass* klass_of_obj_containing_mark) const { |
| if (!UseBiasedLocking) |
| return (!is_unlocked() || !has_no_hash()); |
| return must_be_preserved_with_bias_for_cms_scavenge(klass_of_obj_containing_mark); |
| } |
| |
| inline markOop markOopDesc::prototype_for_object(oop obj) { |
| #ifdef ASSERT |
| markOop prototype_header = obj->klass()->prototype_header(); |
| assert(prototype_header == prototype() || prototype_header->has_bias_pattern(), "corrupt prototype header"); |
| #endif |
| return obj->klass()->prototype_header(); |
| } |
| |
| #endif // SHARE_VM_OOPS_MARKOOP_INLINE_HPP |