1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/oops/markOop.inline.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,113 @@
1.4 +/*
1.5 + * Copyright (c) 2006, 2012, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#ifndef SHARE_VM_OOPS_MARKOOP_INLINE_HPP
1.29 +#define SHARE_VM_OOPS_MARKOOP_INLINE_HPP
1.30 +
1.31 +#include "oops/klass.hpp"
1.32 +#include "oops/markOop.hpp"
1.33 +#include "runtime/globals.hpp"
1.34 +
1.35 +// Should this header be preserved during GC (when biased locking is enabled)?
1.36 +inline bool markOopDesc::must_be_preserved_with_bias(oop obj_containing_mark) const {
1.37 + assert(UseBiasedLocking, "unexpected");
1.38 + if (has_bias_pattern()) {
1.39 + // Will reset bias at end of collection
1.40 + // Mark words of biased and currently locked objects are preserved separately
1.41 + return false;
1.42 + }
1.43 + markOop prototype_header = prototype_for_object(obj_containing_mark);
1.44 + if (prototype_header->has_bias_pattern()) {
1.45 + // Individual instance which has its bias revoked; must return
1.46 + // true for correctness
1.47 + return true;
1.48 + }
1.49 + return (!is_unlocked() || !has_no_hash());
1.50 +}
1.51 +
1.52 +// Should this header be preserved during GC?
1.53 +inline bool markOopDesc::must_be_preserved(oop obj_containing_mark) const {
1.54 + if (!UseBiasedLocking)
1.55 + return (!is_unlocked() || !has_no_hash());
1.56 + return must_be_preserved_with_bias(obj_containing_mark);
1.57 +}
1.58 +
1.59 +// Should this header be preserved in the case of a promotion failure
1.60 +// during scavenge (when biased locking is enabled)?
1.61 +inline bool markOopDesc::must_be_preserved_with_bias_for_promotion_failure(oop obj_containing_mark) const {
1.62 + assert(UseBiasedLocking, "unexpected");
1.63 + // We don't explicitly save off the mark words of biased and
1.64 + // currently-locked objects during scavenges, so if during a
1.65 + // promotion failure we encounter either a biased mark word or a
1.66 + // klass which still has a biasable prototype header, we have to
1.67 + // preserve the mark word. This results in oversaving, but promotion
1.68 + // failures are rare, and this avoids adding more complex logic to
1.69 + // the scavengers to call new variants of
1.70 + // BiasedLocking::preserve_marks() / restore_marks() in the middle
1.71 + // of a scavenge when a promotion failure has first been detected.
1.72 + if (has_bias_pattern() ||
1.73 + prototype_for_object(obj_containing_mark)->has_bias_pattern()) {
1.74 + return true;
1.75 + }
1.76 + return (!is_unlocked() || !has_no_hash());
1.77 +}
1.78 +
1.79 +// Should this header be preserved in the case of a promotion failure
1.80 +// during scavenge?
1.81 +inline bool markOopDesc::must_be_preserved_for_promotion_failure(oop obj_containing_mark) const {
1.82 + if (!UseBiasedLocking)
1.83 + return (!is_unlocked() || !has_no_hash());
1.84 + return must_be_preserved_with_bias_for_promotion_failure(obj_containing_mark);
1.85 +}
1.86 +
1.87 +
1.88 +// Same as must_be_preserved_with_bias_for_promotion_failure() except that
1.89 +// it takes a Klass* argument, instead of the object of which this is the mark word.
1.90 +inline bool markOopDesc::must_be_preserved_with_bias_for_cms_scavenge(Klass* klass_of_obj_containing_mark) const {
1.91 + assert(UseBiasedLocking, "unexpected");
1.92 + // CMS scavenges preserve mark words in similar fashion to promotion failures; see above
1.93 + if (has_bias_pattern() ||
1.94 + klass_of_obj_containing_mark->prototype_header()->has_bias_pattern()) {
1.95 + return true;
1.96 + }
1.97 + return (!is_unlocked() || !has_no_hash());
1.98 +}
1.99 +
1.100 +// Same as must_be_preserved_for_promotion_failure() except that
1.101 +// it takes a Klass* argument, instead of the object of which this is the mark word.
1.102 +inline bool markOopDesc::must_be_preserved_for_cms_scavenge(Klass* klass_of_obj_containing_mark) const {
1.103 + if (!UseBiasedLocking)
1.104 + return (!is_unlocked() || !has_no_hash());
1.105 + return must_be_preserved_with_bias_for_cms_scavenge(klass_of_obj_containing_mark);
1.106 +}
1.107 +
1.108 +inline markOop markOopDesc::prototype_for_object(oop obj) {
1.109 +#ifdef ASSERT
1.110 + markOop prototype_header = obj->klass()->prototype_header();
1.111 + assert(prototype_header == prototype() || prototype_header->has_bias_pattern(), "corrupt prototype header");
1.112 +#endif
1.113 + return obj->klass()->prototype_header();
1.114 +}
1.115 +
1.116 +#endif // SHARE_VM_OOPS_MARKOOP_INLINE_HPP
