50
51 inline jint ObjectMonitor::waiters() const {
52 return _waiters;
53 }
54
55 // Returns NULL if DEFLATER_MARKER is observed.
56 inline void* ObjectMonitor::owner() const {
57 void* owner = _owner;
58 return owner != DEFLATER_MARKER ? owner : NULL;
59 }
60
61 // Returns true if owner field == DEFLATER_MARKER and false otherwise.
62 // This accessor is called when we really need to know if the owner
63 // field == DEFLATER_MARKER and any non-NULL value won't do the trick.
64 inline bool ObjectMonitor::owner_is_DEFLATER_MARKER() {
65 return Atomic::load(&_owner) == DEFLATER_MARKER;
66 }
67
68 // Returns true if 'this' is being async deflated and false otherwise.
69 inline bool ObjectMonitor::is_being_async_deflated() {
70 return AsyncDeflateIdleMonitors && contentions() < 0;
71 }
72
73 inline void ObjectMonitor::clear() {
74 assert(Atomic::load(&_header).value() != 0, "must be non-zero");
75 assert(_owner == NULL, "must be NULL: owner=" INTPTR_FORMAT, p2i(_owner));
76
77 Atomic::store(&_header, markWord::zero());
78
79 clear_common();
80 }
81
82 inline void ObjectMonitor::clear_common() {
83 if (AsyncDeflateIdleMonitors) {
84 // Async deflation protocol uses the header, owner and contentions
85 // fields. While the ObjectMonitor being deflated is on the global
86 // free list, we leave those three fields alone; contentions < 0
87 // will force any racing threads to retry. The header field is used
88 // by install_displaced_markword_in_object() to restore the object's
89 // header so we cannot check its value here.
90 guarantee(_owner == NULL || _owner == DEFLATER_MARKER,
91 "must be NULL or DEFLATER_MARKER: owner=" INTPTR_FORMAT,
92 p2i(_owner));
93 }
94 assert(contentions() <= 0, "must not be positive: contentions=%d", contentions());
95 assert(_waiters == 0, "must be 0: waiters=%d", _waiters);
96 assert(_recursions == 0, "must be 0: recursions=" INTX_FORMAT, _recursions);
97 assert(_object != NULL, "must be non-NULL");
98
99 set_allocation_state(Free);
100 _object = NULL;
101 }
102
103 inline void* ObjectMonitor::object() const {
104 return _object;
105 }
106
107 inline void* ObjectMonitor::object_addr() {
108 return (void *)(&_object);
109 }
110
111 inline void ObjectMonitor::set_object(void* obj) {
112 _object = obj;
113 }
114
115 // Return number of threads contending for this monitor.
116 inline jint ObjectMonitor::contentions() const {
117 return Atomic::load(&_contentions);
118 }
119
120 // Add value to the contentions field.
121 inline void ObjectMonitor::add_to_contentions(jint value) {
122 Atomic::add(&_contentions, value);
123 }
124
125 // Clear _owner field; current value must match old_value.
126 inline void ObjectMonitor::release_clear_owner(void* old_value) {
127 void* prev = Atomic::load(&_owner);
128 ADIM_guarantee(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
129 ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
130 Atomic::release_store(&_owner, (void*)NULL);
131 log_trace(monitorinflation, owner)("release_clear_owner(): mid="
132 INTPTR_FORMAT ", old_value=" INTPTR_FORMAT,
133 p2i(this), p2i(old_value));
134 }
135
136 // Simply set _owner field to new_value; current value must match old_value.
137 // (Simple means no memory sync needed.)
138 inline void ObjectMonitor::set_owner_from(void* old_value, void* new_value) {
139 void* prev = Atomic::load(&_owner);
140 ADIM_guarantee(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
141 ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
142 Atomic::store(&_owner, new_value);
143 log_trace(monitorinflation, owner)("set_owner_from(): mid="
144 INTPTR_FORMAT ", old_value=" INTPTR_FORMAT
145 ", new_value=" INTPTR_FORMAT, p2i(this),
146 p2i(old_value), p2i(new_value));
147 }
148
149 // Simply set _owner field to new_value; current value must match old_value1 or old_value2.
150 // (Simple means no memory sync needed.)
151 inline void ObjectMonitor::set_owner_from(void* old_value1, void* old_value2, void* new_value) {
152 void* prev = Atomic::load(&_owner);
153 ADIM_guarantee(prev == old_value1 || prev == old_value2,
154 "unexpected prev owner=" INTPTR_FORMAT ", expected1="
155 INTPTR_FORMAT " or expected2=" INTPTR_FORMAT, p2i(prev),
156 p2i(old_value1), p2i(old_value2));
157 _owner = new_value;
158 log_trace(monitorinflation, owner)("set_owner_from(old1=" INTPTR_FORMAT
159 ", old2=" INTPTR_FORMAT "): mid="
160 INTPTR_FORMAT ", prev=" INTPTR_FORMAT
161 ", new=" INTPTR_FORMAT, p2i(old_value1),
162 p2i(old_value2), p2i(this), p2i(prev),
163 p2i(new_value));
164 }
165
166 // Simply set _owner field to self; current value must match basic_lock_p.
167 inline void ObjectMonitor::set_owner_from_BasicLock(void* basic_lock_p, Thread* self) {
168 void* prev = Atomic::load(&_owner);
169 ADIM_guarantee(prev == basic_lock_p, "unexpected prev owner=" INTPTR_FORMAT
170 ", expected=" INTPTR_FORMAT, p2i(prev), p2i(basic_lock_p));
171 // Non-null owner field to non-null owner field is safe without
172 // cmpxchg() as long as all readers can tolerate either flavor.
173 Atomic::store(&_owner, self);
174 log_trace(monitorinflation, owner)("set_owner_from_BasicLock(): mid="
175 INTPTR_FORMAT ", basic_lock_p="
176 INTPTR_FORMAT ", new_value=" INTPTR_FORMAT,
177 p2i(this), p2i(basic_lock_p), p2i(self));
178 }
179
180 // Try to set _owner field to new_value if the current value matches
181 // old_value. Otherwise, does not change the _owner field. Returns
182 // the prior value of the _owner field.
183 inline void* ObjectMonitor::try_set_owner_from(void* old_value, void* new_value) {
184 void* prev = Atomic::cmpxchg(&_owner, old_value, new_value);
185 if (prev == old_value) {
186 log_trace(monitorinflation, owner)("try_set_owner_from(): mid="
187 INTPTR_FORMAT ", prev=" INTPTR_FORMAT
188 ", new=" INTPTR_FORMAT, p2i(this),
189 p2i(prev), p2i(new_value));
190 }
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50
51 inline jint ObjectMonitor::waiters() const {
52 return _waiters;
53 }
54
55 // Returns NULL if DEFLATER_MARKER is observed.
56 inline void* ObjectMonitor::owner() const {
57 void* owner = _owner;
58 return owner != DEFLATER_MARKER ? owner : NULL;
59 }
60
61 // Returns true if owner field == DEFLATER_MARKER and false otherwise.
62 // This accessor is called when we really need to know if the owner
63 // field == DEFLATER_MARKER and any non-NULL value won't do the trick.
64 inline bool ObjectMonitor::owner_is_DEFLATER_MARKER() {
65 return Atomic::load(&_owner) == DEFLATER_MARKER;
66 }
67
68 // Returns true if 'this' is being async deflated and false otherwise.
69 inline bool ObjectMonitor::is_being_async_deflated() {
70 return contentions() < 0;
71 }
72
73 inline void ObjectMonitor::clear() {
74 assert(Atomic::load(&_header).value() != 0, "must be non-zero");
75 assert(_owner == NULL, "must be NULL: owner=" INTPTR_FORMAT, p2i(_owner));
76
77 Atomic::store(&_header, markWord::zero());
78
79 clear_common();
80 }
81
82 inline void ObjectMonitor::clear_common() {
83 // Async deflation protocol uses the header, owner and contentions
84 // fields. While the ObjectMonitor being deflated is on the global
85 // free list, we leave those three fields alone; contentions < 0
86 // will force any racing threads to retry. The header field is used
87 // by install_displaced_markword_in_object() to restore the object's
88 // header so we cannot check its value here.
89 guarantee(_owner == NULL || _owner == DEFLATER_MARKER,
90 "must be NULL or DEFLATER_MARKER: owner=" INTPTR_FORMAT,
91 p2i(_owner));
92 assert(contentions() <= 0, "must not be positive: contentions=%d", contentions());
93 assert(_waiters == 0, "must be 0: waiters=%d", _waiters);
94 assert(_recursions == 0, "must be 0: recursions=" INTX_FORMAT, _recursions);
95 assert(_object != NULL, "must be non-NULL");
96
97 set_allocation_state(Free);
98 _object = NULL;
99 }
100
101 inline void* ObjectMonitor::object() const {
102 return _object;
103 }
104
105 inline void* ObjectMonitor::object_addr() {
106 return (void *)(&_object);
107 }
108
109 inline void ObjectMonitor::set_object(void* obj) {
110 _object = obj;
111 }
112
113 // Return number of threads contending for this monitor.
114 inline jint ObjectMonitor::contentions() const {
115 return Atomic::load(&_contentions);
116 }
117
118 // Add value to the contentions field.
119 inline void ObjectMonitor::add_to_contentions(jint value) {
120 Atomic::add(&_contentions, value);
121 }
122
123 // Clear _owner field; current value must match old_value.
124 inline void ObjectMonitor::release_clear_owner(void* old_value) {
125 #ifdef ASSERT
126 void* prev = Atomic::load(&_owner);
127 assert(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
128 ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
129 #endif
130 Atomic::release_store(&_owner, (void*)NULL);
131 log_trace(monitorinflation, owner)("release_clear_owner(): mid="
132 INTPTR_FORMAT ", old_value=" INTPTR_FORMAT,
133 p2i(this), p2i(old_value));
134 }
135
136 // Simply set _owner field to new_value; current value must match old_value.
137 // (Simple means no memory sync needed.)
138 inline void ObjectMonitor::set_owner_from(void* old_value, void* new_value) {
139 #ifdef ASSERT
140 void* prev = Atomic::load(&_owner);
141 assert(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
142 ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
143 #endif
144 Atomic::store(&_owner, new_value);
145 log_trace(monitorinflation, owner)("set_owner_from(): mid="
146 INTPTR_FORMAT ", old_value=" INTPTR_FORMAT
147 ", new_value=" INTPTR_FORMAT, p2i(this),
148 p2i(old_value), p2i(new_value));
149 }
150
151 // Simply set _owner field to new_value; current value must match old_value1 or old_value2.
152 // (Simple means no memory sync needed.)
153 inline void ObjectMonitor::set_owner_from(void* old_value1, void* old_value2, void* new_value) {
154 void* prev = Atomic::load(&_owner);
155 assert(prev == old_value1 || prev == old_value2,
156 "unexpected prev owner=" INTPTR_FORMAT ", expected1="
157 INTPTR_FORMAT " or expected2=" INTPTR_FORMAT, p2i(prev),
158 p2i(old_value1), p2i(old_value2));
159 _owner = new_value;
160 log_trace(monitorinflation, owner)("set_owner_from(old1=" INTPTR_FORMAT
161 ", old2=" INTPTR_FORMAT "): mid="
162 INTPTR_FORMAT ", prev=" INTPTR_FORMAT
163 ", new=" INTPTR_FORMAT, p2i(old_value1),
164 p2i(old_value2), p2i(this), p2i(prev),
165 p2i(new_value));
166 }
167
168 // Simply set _owner field to self; current value must match basic_lock_p.
169 inline void ObjectMonitor::set_owner_from_BasicLock(void* basic_lock_p, Thread* self) {
170 #ifdef ASSERT
171 void* prev = Atomic::load(&_owner);
172 assert(prev == basic_lock_p, "unexpected prev owner=" INTPTR_FORMAT
173 ", expected=" INTPTR_FORMAT, p2i(prev), p2i(basic_lock_p));
174 #endif
175 // Non-null owner field to non-null owner field is safe without
176 // cmpxchg() as long as all readers can tolerate either flavor.
177 Atomic::store(&_owner, self);
178 log_trace(monitorinflation, owner)("set_owner_from_BasicLock(): mid="
179 INTPTR_FORMAT ", basic_lock_p="
180 INTPTR_FORMAT ", new_value=" INTPTR_FORMAT,
181 p2i(this), p2i(basic_lock_p), p2i(self));
182 }
183
184 // Try to set _owner field to new_value if the current value matches
185 // old_value. Otherwise, does not change the _owner field. Returns
186 // the prior value of the _owner field.
187 inline void* ObjectMonitor::try_set_owner_from(void* old_value, void* new_value) {
188 void* prev = Atomic::cmpxchg(&_owner, old_value, new_value);
189 if (prev == old_value) {
190 log_trace(monitorinflation, owner)("try_set_owner_from(): mid="
191 INTPTR_FORMAT ", prev=" INTPTR_FORMAT
192 ", new=" INTPTR_FORMAT, p2i(this),
193 p2i(prev), p2i(new_value));
194 }
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