1 /*
 2  * Copyright (c) 2005, 2022, 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
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 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
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17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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24 
25 #ifndef SHARE_OOPS_KLASS_INLINE_HPP
26 #define SHARE_OOPS_KLASS_INLINE_HPP
27 
28 #include "oops/klass.hpp"
29 
30 #include "classfile/classLoaderData.inline.hpp"
31 #include "oops/klassVtable.hpp"
32 #include "oops/markWord.hpp"
33 
34 // This loads and keeps the klass's loader alive.
35 inline oop Klass::klass_holder() const {
36   return class_loader_data()->holder();
37 }
38 
39 inline bool Klass::is_non_strong_hidden() const {
40   return access_flags().is_hidden_class() &&
41          class_loader_data()->has_class_mirror_holder();
42 }
43 
44 // Iff the class loader (or mirror for non-strong hidden classes) is alive the
45 // Klass is considered alive. This is safe to call before the CLD is marked as
46 // unloading, and hence during concurrent class unloading.
47 // This returns false if the Klass is unloaded, or about to be unloaded because the holder of
48 // the CLD is no longer strongly reachable.
49 // The return value of this function may change from true to false after a safepoint. So the caller
50 // of this function must ensure that a safepoint doesn't happen while interpreting the return value.
51 inline bool Klass::is_loader_alive() const {
52   return class_loader_data()->is_alive();
53 }
54 
55 inline void Klass::set_prototype_header(markWord header) {
56   assert(UseCompactObjectHeaders, "only with compact headers");
57   _prototype_header = header;
58 }
59 
60 inline oop Klass::java_mirror() const {
61   return _java_mirror.resolve();
62 }
63 
64 inline oop Klass::java_mirror_no_keepalive() const {
65   return _java_mirror.peek();
66 }
67 
68 inline klassVtable Klass::vtable() const {
69   return klassVtable(const_cast<Klass*>(this), start_of_vtable(), vtable_length() / vtableEntry::size());
70 }
71 
72 inline oop Klass::class_loader() const {
73   return class_loader_data()->class_loader();
74 }
75 
76 inline vtableEntry* Klass::start_of_vtable() const {
77   return (vtableEntry*) ((address)this + in_bytes(vtable_start_offset()));
78 }
79 
80 inline ByteSize Klass::vtable_start_offset() {
81   return in_ByteSize(InstanceKlass::header_size() * wordSize);
82 }
83 
84 #endif // SHARE_OOPS_KLASS_INLINE_HPP