1 /*
2 * Copyright (c) 1998, 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_RUNTIME_OBJECTMONITOR_INLINE_HPP
26 #define SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP
27
28 #include "logging/log.hpp"
29 #include "runtime/atomic.hpp"
30
31 inline intptr_t ObjectMonitor::is_entered(TRAPS) const {
32 if (THREAD == _owner || THREAD->is_lock_owned((address) _owner)) {
33 return 1;
34 }
35 return 0;
36 }
37
38 inline markWord ObjectMonitor::header() const {
39 return Atomic::load(&_header);
40 }
41
42 inline volatile markWord* ObjectMonitor::header_addr() {
43 assert((intptr_t)this == (intptr_t)&_header, "sync code expects this");
44 return &_header;
45 }
46
47 inline void ObjectMonitor::set_header(markWord hdr) {
48 Atomic::store(&_header, hdr);
49 }
50
51 inline jint ObjectMonitor::waiters() const {
52 return _waiters;
53 }
54
55 inline void* ObjectMonitor::owner() const {
56 return _owner;
57 }
58
59 inline void ObjectMonitor::clear() {
60 assert(Atomic::load(&_header).value() != 0, "must be non-zero");
61 assert(_contentions == 0, "must be 0: contentions=%d", _contentions);
62 assert(_waiters == 0, "must be 0: waiters=%d", _waiters);
63 assert(_recursions == 0, "must be 0: recursions=" INTX_FORMAT, _recursions);
64 assert(_object != NULL, "must be non-NULL");
65 assert(_owner == NULL, "must be NULL: owner=" INTPTR_FORMAT, p2i(_owner));
66
67 Atomic::store(&_header, markWord::zero());
68 _object = NULL;
69 }
70
71 inline void* ObjectMonitor::object() const {
72 return _object;
73 }
74
75 inline void* ObjectMonitor::object_addr() {
76 return (void *)(&_object);
77 }
78
79 inline void ObjectMonitor::set_object(void* obj) {
80 _object = obj;
81 }
82
83 // return number of threads contending for this monitor
84 inline jint ObjectMonitor::contentions() const {
85 return _contentions;
86 }
87
88 // Clear _owner field; current value must match old_value.
89 inline void ObjectMonitor::release_clear_owner(void* old_value) {
90 void* prev = _owner;
91 assert(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
92 ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
93 Atomic::release_store(&_owner, (void*)NULL);
94 log_trace(monitorinflation, owner)("release_clear_owner(): mid="
95 INTPTR_FORMAT ", prev=" INTPTR_FORMAT,
96 p2i(this), p2i(prev));
97 }
98
99 // Simply set _owner field to new_value; current value must match old_value.
100 // (Simple means no memory sync needed.)
101 inline void ObjectMonitor::set_owner_from(void* old_value, void* new_value) {
102 void* prev = _owner;
103 assert(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
104 ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
105 _owner = new_value;
106 log_trace(monitorinflation, owner)("set_owner_from(): mid="
107 INTPTR_FORMAT ", prev=" INTPTR_FORMAT
108 ", new=" INTPTR_FORMAT, p2i(this),
109 p2i(prev), p2i(new_value));
110 }
111
112 // Simply set _owner field to self; current value must match basic_lock_p.
113 inline void ObjectMonitor::set_owner_from_BasicLock(void* basic_lock_p, Thread* self) {
114 void* prev = _owner;
115 assert(prev == basic_lock_p, "unexpected prev owner=" INTPTR_FORMAT
116 ", expected=" INTPTR_FORMAT, p2i(prev), p2i(basic_lock_p));
117 // Non-null owner field to non-null owner field is safe without
118 // cmpxchg() as long as all readers can tolerate either flavor.
119 _owner = self;
120 log_trace(monitorinflation, owner)("set_owner_from_BasicLock(): mid="
121 INTPTR_FORMAT ", prev=" INTPTR_FORMAT
122 ", new=" INTPTR_FORMAT ", basic_lock_p="
123 INTPTR_FORMAT, p2i(this), p2i(prev),
124 p2i(self), p2i(basic_lock_p));
125 }
126
127 // Try to set _owner field to new_value if the current value matches
128 // old_value. Otherwise, does not change the _owner field.
129 inline void* ObjectMonitor::try_set_owner_from(void* old_value, void* new_value) {
130 void* prev = Atomic::cmpxchg(&_owner, old_value, new_value);
131 if (prev == old_value) {
132 log_trace(monitorinflation, owner)("try_set_owner_from(): mid="
133 INTPTR_FORMAT ", prev=" INTPTR_FORMAT
134 ", new=" INTPTR_FORMAT, p2i(this),
135 p2i(prev), p2i(new_value));
136 }
137 return prev;
138 }
139
140 #endif // SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP