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 inline intptr_t ObjectMonitor::is_entered(TRAPS) const {
29 if (THREAD == _owner || THREAD->is_lock_owned((address) _owner)) {
30 return 1;
31 }
32 return 0;
33 }
34
35 inline markOop ObjectMonitor::header() const {
36 return _header;
37 }
38
39 inline volatile markOop* ObjectMonitor::header_addr() {
40 assert((intptr_t)this == (intptr_t)&_header, "sync code expects this");
41 return &_header;
42 }
43
44 inline void ObjectMonitor::set_header(markOop hdr) {
45 _header = hdr;
46 }
47
48 inline jint ObjectMonitor::waiters() const {
49 return _waiters;
50 }
51
52 // Returns NULL if DEFLATER_MARKER is observed.
53 inline void* ObjectMonitor::owner() const {
54 void* owner = _owner;
55 return owner != DEFLATER_MARKER ? owner : NULL;
56 }
57
58 // Returns true if owner field == DEFLATER_MARKER and false otherwise.
59 // This accessor is called when we really need to know if the owner
60 // field == DEFLATER_MARKER and any non-NULL value won't do the trick.
61 inline bool ObjectMonitor::owner_is_DEFLATER_MARKER() {
62 return OrderAccess::load_acquire(&_owner) == DEFLATER_MARKER;
63 }
64
65 inline void ObjectMonitor::clear() {
66 assert(_header != NULL, "must be non-NULL");
67 assert(_owner == NULL, "must be NULL: owner=" INTPTR_FORMAT, p2i(_owner));
68 assert(ref_count() == 0, "must be 0: ref_count=%d", ref_count());
69
70 _header = NULL;
71
72 clear_using_JT();
73 }
74
75 inline void ObjectMonitor::clear_using_JT() {
76 // Unlike other *_using_JT() functions, we cannot assert
77 // AsyncDeflateIdleMonitors or Thread::current()->is_Java_thread()
78 // because clear() calls this function for the rest of its checks.
79
80 if (AsyncDeflateIdleMonitors) {
81 // Async deflation protocol uses the header, owner and ref_count
82 // fields. While the ObjectMonitor being deflated is on the global free
83 // list, we leave those three fields alone; owner == DEFLATER_MARKER
84 // and ref_count < 0 will force any racing threads to retry. The
85 // header field is used by install_displaced_markword_in_object()
86 // in the last part of the deflation protocol so we cannot check
87 // its value here.
88 guarantee(_owner == NULL || _owner == DEFLATER_MARKER,
89 "must be NULL or DEFLATER_MARKER: owner=" INTPTR_FORMAT,
90 p2i(_owner));
91 guarantee(ref_count() <= 0, "must be <= 0: ref_count=%d", ref_count());
92 }
93 assert(_contentions == 0, "must be 0: contentions=%d", _contentions);
94 assert(_waiters == 0, "must be 0: waiters=%d", _waiters);
95 assert(_recursions == 0, "must be 0: recursions=" INTPTR_FORMAT, _recursions);
96 assert(_object != NULL, "must be non-NULL");
97
98 set_allocation_state(Free);
99 _object = NULL;
100 }
101
102 inline void* ObjectMonitor::object() const {
103 return _object;
104 }
105
106 inline void* ObjectMonitor::object_addr() {
107 return (void *)(&_object);
108 }
109
110 inline void ObjectMonitor::set_object(void* obj) {
111 _object = obj;
112 }
113
114 inline bool ObjectMonitor::check(TRAPS) {
115 if (THREAD != _owner) {
116 if (THREAD->is_lock_owned((address) _owner)) {
117 _owner = THREAD; // regain ownership of inflated monitor
118 assert (_recursions == 0, "invariant") ;
119 } else {
120 check_slow(THREAD);
121 return false;
122 }
123 }
124 return true;
125 }
126
127 // return number of threads contending for this monitor
128 inline jint ObjectMonitor::contentions() const {
129 return _contentions;
130 }
131
132 inline void ObjectMonitor::set_owner(void* owner) {
133 _owner = owner;
134 }
135
136 inline void ObjectMonitor::set_allocation_state(ObjectMonitor::AllocationState s) {
137 _allocation_state = s;
138 }
139
140 inline ObjectMonitor::AllocationState ObjectMonitor::allocation_state() const {
141 return _allocation_state;
142 }
143
144 inline bool ObjectMonitor::is_free() const {
145 return _allocation_state == Free;
146 }
147
148 inline bool ObjectMonitor::is_active() const {
149 return !is_free();
150 }
151
152 inline bool ObjectMonitor::is_old() const {
153 return _allocation_state == Old;
154 }
155
156 inline bool ObjectMonitor::is_new() const {
157 return _allocation_state == New;
158 }
159
160 inline void ObjectMonitor::dec_ref_count() {
161 // The decrement only needs to be MO_ACQ_REL since the reference
162 // counter is volatile.
163 Atomic::dec(&_ref_count);
164 // Can be negative as part of async deflation protocol.
165 ADIM_guarantee(AsyncDeflateIdleMonitors || ref_count() >= 0,
166 "sanity check: ref_count=%d", ref_count());
167 }
168
169 inline void ObjectMonitor::inc_ref_count() {
170 // The increment needs to be MO_SEQ_CST so that the reference
171 // counter update is seen as soon as possible in a race with the
172 // async deflation protocol.
173 Atomic::inc(&_ref_count);
174 // Can be negative as part of async deflation protocol.
175 ADIM_guarantee(AsyncDeflateIdleMonitors || ref_count() > 0,
176 "sanity check: ref_count=%d", ref_count());
177 }
178
179 inline jint ObjectMonitor::ref_count() const {
180 return OrderAccess::load_acquire(&_ref_count);
181 }
182
183 #endif // SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP