67 //
68 // This method is pretty bulky. It would be nice to split it up
69 // into smaller submethods, but we need to be careful not to hurt
70 // performance.
71 //
72 template<bool promote_immediately>
73 oop PSPromotionManager::copy_to_survivor_space(oop o) {
74 assert(PSScavenge::should_scavenge(&o), "Sanity");
75
76 oop new_obj = NULL;
77
78 // NOTE! We must be very careful with any methods that access the mark
79 // in o. There may be multiple threads racing on it, and it may be forwarded
80 // at any time. Do not use oop methods for accessing the mark!
81 markOop test_mark = o->mark();
82
83 // The same test as "o->is_forwarded()"
84 if (!test_mark->is_marked()) {
85 bool new_obj_is_tenured = false;
86 size_t new_obj_size = o->size();
87
88 if (!promote_immediately) {
89 // Find the objects age, MT safe.
90 uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
91 test_mark->displaced_mark_helper()->age() : test_mark->age();
92
93 // Try allocating obj in to-space (unless too old)
94 if (age < PSScavenge::tenuring_threshold()) {
95 new_obj = (oop) _young_lab.allocate(new_obj_size);
96 if (new_obj == NULL && !_young_gen_is_full) {
97 // Do we allocate directly, or flush and refill?
98 if (new_obj_size > (YoungPLABSize / 2)) {
99 // Allocate this object directly
100 new_obj = (oop)young_space()->cas_allocate(new_obj_size);
101 } else {
102 // Flush and fill
103 _young_lab.flush();
104
105 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
106 if (lab_base != NULL) {
107 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
108 // Try the young lab allocation again.
109 new_obj = (oop) _young_lab.allocate(new_obj_size);
110 } else {
111 _young_gen_is_full = true;
112 }
113 }
114 }
115 }
116 }
117
118 // Otherwise try allocating obj tenured
119 if (new_obj == NULL) {
120 #ifndef PRODUCT
121 if (Universe::heap()->promotion_should_fail()) {
122 return oop_promotion_failed(o, test_mark);
123 }
124 #endif // #ifndef PRODUCT
125
126 new_obj = (oop) _old_lab.allocate(new_obj_size);
127 new_obj_is_tenured = true;
128
129 if (new_obj == NULL) {
130 if (!_old_gen_is_full) {
131 // Do we allocate directly, or flush and refill?
132 if (new_obj_size > (OldPLABSize / 2)) {
133 // Allocate this object directly
134 new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
135 } else {
136 // Flush and fill
137 _old_lab.flush();
138
139 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
140 if(lab_base != NULL) {
141 #ifdef ASSERT
142 // Delay the initialization of the promotion lab (plab).
143 // This exposes uninitialized plabs to card table processing.
144 if (GCWorkerDelayMillis > 0) {
145 os::sleep(Thread::current(), GCWorkerDelayMillis, false);
146 }
147 #endif
148 _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
149 // Try the old lab allocation again.
150 new_obj = (oop) _old_lab.allocate(new_obj_size);
151 }
152 }
153 }
154
155 // This is the promotion failed test, and code handling.
156 // The code belongs here for two reasons. It is slightly
157 // different than the code below, and cannot share the
158 // CAS testing code. Keeping the code here also minimizes
159 // the impact on the common case fast path code.
160
161 if (new_obj == NULL) {
162 _old_gen_is_full = true;
163 return oop_promotion_failed(o, test_mark);
164 }
165 }
166 }
167
168 assert(new_obj != NULL, "allocation should have succeeded");
169
170 // Copy obj
|
67 //
68 // This method is pretty bulky. It would be nice to split it up
69 // into smaller submethods, but we need to be careful not to hurt
70 // performance.
71 //
72 template<bool promote_immediately>
73 oop PSPromotionManager::copy_to_survivor_space(oop o) {
74 assert(PSScavenge::should_scavenge(&o), "Sanity");
75
76 oop new_obj = NULL;
77
78 // NOTE! We must be very careful with any methods that access the mark
79 // in o. There may be multiple threads racing on it, and it may be forwarded
80 // at any time. Do not use oop methods for accessing the mark!
81 markOop test_mark = o->mark();
82
83 // The same test as "o->is_forwarded()"
84 if (!test_mark->is_marked()) {
85 bool new_obj_is_tenured = false;
86 size_t new_obj_size = o->size();
87 // Find the objects age, MT safe.
88 uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
89 test_mark->displaced_mark_helper()->age() : test_mark->age();
90
91 if (!promote_immediately) {
92 // Try allocating obj in to-space (unless too old)
93 if (age < PSScavenge::tenuring_threshold()) {
94 new_obj = (oop) _young_lab.allocate(new_obj_size);
95 if (new_obj == NULL && !_young_gen_is_full) {
96 // Do we allocate directly, or flush and refill?
97 if (new_obj_size > (YoungPLABSize / 2)) {
98 // Allocate this object directly
99 new_obj = (oop)young_space()->cas_allocate(new_obj_size);
100 if (new_obj != NULL) {
101 PSScavenge::gc_tracer()->report_promotion_outside_plab_event(o,
102 new_obj_size,
103 age,
104 false);
105 }
106 } else {
107 // Flush and fill
108 _young_lab.flush();
109
110 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
111 if (lab_base != NULL) {
112 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
113 // Try the young lab allocation again.
114 new_obj = (oop) _young_lab.allocate(new_obj_size);
115 if (new_obj != NULL) {
116 size_t lab_size = pointer_delta(_young_lab.end(), _young_lab.bottom());
117 PSScavenge::gc_tracer()->report_promotion_in_new_plab_event(o,
118 new_obj_size,
119 age,
120 false,
121 lab_size);
122 }
123 } else {
124 _young_gen_is_full = true;
125 }
126 }
127 }
128 }
129 }
130
131 // Otherwise try allocating obj tenured
132 if (new_obj == NULL) {
133 #ifndef PRODUCT
134 if (Universe::heap()->promotion_should_fail()) {
135 return oop_promotion_failed(o, test_mark);
136 }
137 #endif // #ifndef PRODUCT
138
139 new_obj = (oop) _old_lab.allocate(new_obj_size);
140 new_obj_is_tenured = true;
141
142 if (new_obj == NULL) {
143 if (!_old_gen_is_full) {
144 // Do we allocate directly, or flush and refill?
145 if (new_obj_size > (OldPLABSize / 2)) {
146 // Allocate this object directly
147 new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
148 if (new_obj != NULL) {
149 PSScavenge::gc_tracer()->report_promotion_outside_plab_event(o,
150 new_obj_size,
151 age,
152 true);
153 }
154 } else {
155 // Flush and fill
156 _old_lab.flush();
157
158 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
159 if(lab_base != NULL) {
160 #ifdef ASSERT
161 // Delay the initialization of the promotion lab (plab).
162 // This exposes uninitialized plabs to card table processing.
163 if (GCWorkerDelayMillis > 0) {
164 os::sleep(Thread::current(), GCWorkerDelayMillis, false);
165 }
166 #endif
167 _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
168 // Try the old lab allocation again.
169 new_obj = (oop) _old_lab.allocate(new_obj_size);
170 if (new_obj != NULL) {
171 size_t lab_size = pointer_delta(_old_lab.end(), _old_lab.bottom());
172 PSScavenge::gc_tracer()->report_promotion_in_new_plab_event(o,
173 new_obj_size,
174 age,
175 true,
176 lab_size);
177 }
178 }
179 }
180 }
181
182 // This is the promotion failed test, and code handling.
183 // The code belongs here for two reasons. It is slightly
184 // different than the code below, and cannot share the
185 // CAS testing code. Keeping the code here also minimizes
186 // the impact on the common case fast path code.
187
188 if (new_obj == NULL) {
189 _old_gen_is_full = true;
190 return oop_promotion_failed(o, test_mark);
191 }
192 }
193 }
194
195 assert(new_obj != NULL, "allocation should have succeeded");
196
197 // Copy obj
|