1 /*
2 * Copyright (c) 2002, 2012, 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.
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23 */
24
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP
27
28 #include "gc_implementation/parallelScavenge/psOldGen.hpp"
29 #include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
30 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
31
32 inline PSPromotionManager* PSPromotionManager::manager_array(int index) {
33 assert(_manager_array != NULL, "access of NULL manager_array");
34 assert(index >= 0 && index <= (int)ParallelGCThreads, "out of range manager_array access");
35 return _manager_array[index];
36 }
37
38 template <class T>
39 inline void PSPromotionManager::claim_or_forward_internal_depth(T* p) {
40 if (p != NULL) { // XXX: error if p != NULL here
41 oop o = oopDesc::load_decode_heap_oop_not_null(p);
42 if (o->is_forwarded()) {
43 o = o->forwardee();
44 // Card mark
45 if (PSScavenge::is_obj_in_young(o)) {
46 PSScavenge::card_table()->inline_write_ref_field_gc(p, o);
47 }
48 oopDesc::encode_store_heap_oop_not_null(p, o);
49 } else {
50 push_depth(p);
51 }
52 }
53 }
54
55 template <class T>
56 inline void PSPromotionManager::claim_or_forward_depth(T* p) {
57 assert(PSScavenge::should_scavenge(p, true), "revisiting object?");
58 assert(Universe::heap()->kind() == CollectedHeap::ParallelScavengeHeap,
59 "Sanity");
60 assert(Universe::heap()->is_in(p), "pointer outside heap");
61
62 claim_or_forward_internal_depth(p);
63 }
64
65 //
66 // This method is pretty bulky. It would be nice to split it up
67 // into smaller submethods, but we need to be careful not to hurt
68 // performance.
69 //
70 template<bool promote_immediately>
71 oop PSPromotionManager::copy_to_survivor_space(oop o) {
72 assert(PSScavenge::should_scavenge(&o), "Sanity");
73
74 oop new_obj = NULL;
75
76 // NOTE! We must be very careful with any methods that access the mark
77 // in o. There may be multiple threads racing on it, and it may be forwarded
78 // at any time. Do not use oop methods for accessing the mark!
79 markOop test_mark = o->mark();
80
81 // The same test as "o->is_forwarded()"
82 if (!test_mark->is_marked()) {
83 bool new_obj_is_tenured = false;
84 size_t new_obj_size = o->size();
85
86 if (!promote_immediately) {
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 // Try allocating obj in to-space (unless too old)
92 if (age < PSScavenge::tenuring_threshold()) {
93 new_obj = (oop) _young_lab.allocate(new_obj_size);
94 if (new_obj == NULL && !_young_gen_is_full) {
95 // Do we allocate directly, or flush and refill?
96 if (new_obj_size > (YoungPLABSize / 2)) {
97 // Allocate this object directly
98 new_obj = (oop)young_space()->cas_allocate(new_obj_size);
99 } else {
100 // Flush and fill
101 _young_lab.flush();
102
103 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
104 if (lab_base != NULL) {
105 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
106 // Try the young lab allocation again.
107 new_obj = (oop) _young_lab.allocate(new_obj_size);
108 } else {
109 _young_gen_is_full = true;
110 }
111 }
112 }
113 }
114 }
115
116 // Otherwise try allocating obj tenured
117 if (new_obj == NULL) {
118 #ifndef PRODUCT
119 if (Universe::heap()->promotion_should_fail()) {
120 return oop_promotion_failed(o, test_mark);
121 }
122 #endif // #ifndef PRODUCT
123
124 new_obj = (oop) _old_lab.allocate(new_obj_size);
125 new_obj_is_tenured = true;
126
127 if (new_obj == NULL) {
128 if (!_old_gen_is_full) {
129 // Do we allocate directly, or flush and refill?
130 if (new_obj_size > (OldPLABSize / 2)) {
131 // Allocate this object directly
132 new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
133 } else {
134 // Flush and fill
135 _old_lab.flush();
136
137 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
138 if(lab_base != NULL) {
139 #ifdef ASSERT
140 // Delay the initialization of the promotion lab (plab).
141 // This exposes uninitialized plabs to card table processing.
142 if (GCWorkerDelayMillis > 0) {
143 os::sleep(Thread::current(), GCWorkerDelayMillis, false);
144 }
145 #endif
146 _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
147 // Try the old lab allocation again.
148 new_obj = (oop) _old_lab.allocate(new_obj_size);
149 }
150 }
151 }
152
153 // This is the promotion failed test, and code handling.
154 // The code belongs here for two reasons. It is slightly
155 // different thatn the code below, and cannot share the
156 // CAS testing code. Keeping the code here also minimizes
157 // the impact on the common case fast path code.
158
159 if (new_obj == NULL) {
160 _old_gen_is_full = true;
161 return oop_promotion_failed(o, test_mark);
162 }
163 }
164 }
165
166 assert(new_obj != NULL, "allocation should have succeeded");
167
168 // Copy obj
169 Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
170
171 // Now we have to CAS in the header.
172 if (o->cas_forward_to(new_obj, test_mark)) {
173 // We won any races, we "own" this object.
174 assert(new_obj == o->forwardee(), "Sanity");
175
176 // Increment age if obj still in new generation. Now that
177 // we're dealing with a markOop that cannot change, it is
178 // okay to use the non mt safe oop methods.
179 if (!new_obj_is_tenured) {
180 new_obj->incr_age();
181 assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
182 }
183
184 // Do the size comparison first with new_obj_size, which we
185 // already have. Hopefully, only a few objects are larger than
186 // _min_array_size_for_chunking, and most of them will be arrays.
187 // So, the is->objArray() test would be very infrequent.
188 if (new_obj_size > _min_array_size_for_chunking &&
189 new_obj->is_objArray() &&
190 PSChunkLargeArrays) {
191 // we'll chunk it
192 oop* const masked_o = mask_chunked_array_oop(o);
193 push_depth(masked_o);
194 TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
195 } else {
196 // we'll just push its contents
197 new_obj->push_contents(this);
198 }
199 } else {
200 // We lost, someone else "owns" this object
201 guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
202
203 // Try to deallocate the space. If it was directly allocated we cannot
204 // deallocate it, so we have to test. If the deallocation fails,
205 // overwrite with a filler object.
206 if (new_obj_is_tenured) {
207 if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
208 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
209 }
210 } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
211 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
212 }
213
214 // don't update this before the unallocation!
215 new_obj = o->forwardee();
216 }
217 } else {
218 assert(o->is_forwarded(), "Sanity");
219 new_obj = o->forwardee();
220 }
221
222 #ifndef PRODUCT
223 // This code must come after the CAS test, or it will print incorrect
224 // information.
225 if (TraceScavenge) {
226 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
227 PSScavenge::should_scavenge(&new_obj) ? "copying" : "tenuring",
228 new_obj->klass()->internal_name(), o, new_obj, new_obj->size());
229 }
230 #endif
231
232 return new_obj;
233 }
234
235
236 inline void PSPromotionManager::process_popped_location_depth(StarTask p) {
237 if (is_oop_masked(p)) {
238 assert(PSChunkLargeArrays, "invariant");
239 oop const old = unmask_chunked_array_oop(p);
240 process_array_chunk(old);
241 } else {
242 if (p.is_narrow()) {
243 assert(UseCompressedOops, "Error");
244 PSScavenge::copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(this, p);
245 } else {
246 PSScavenge::copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(this, p);
247 }
248 }
249 }
250
251 #if TASKQUEUE_STATS
252 void PSPromotionManager::record_steal(StarTask& p) {
253 if (is_oop_masked(p)) {
254 ++_masked_steals;
255 }
256 }
257 #endif // TASKQUEUE_STATS
258
259 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP