1 /*
2 * Copyright (c) 2002, 2014, 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.
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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/psPromotionLAB.inline.hpp"
31 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
32 #include "gc_interface/collectedHeap.inline.hpp"
33 #include "oops/oop.psgc.inline.hpp"
34
35 inline PSPromotionManager* PSPromotionManager::manager_array(int index) {
36 assert(_manager_array != NULL, "access of NULL manager_array");
37 assert(index >= 0 && index <= (int)ParallelGCThreads, "out of range manager_array access");
38 return &_manager_array[index];
39 }
40
41 template <class T>
42 inline void PSPromotionManager::claim_or_forward_internal_depth(T* p) {
43 if (p != NULL) { // XXX: error if p != NULL here
44 oop o = oopDesc::load_decode_heap_oop_not_null(p);
45 if (o->is_forwarded()) {
46 o = o->forwardee();
47 // Card mark
48 if (PSScavenge::is_obj_in_young(o)) {
49 PSScavenge::card_table()->inline_write_ref_field_gc(p, o);
50 }
51 oopDesc::encode_store_heap_oop_not_null(p, o);
52 } else {
53 push_depth(p);
54 }
55 }
56 }
57
58 template <class T>
59 inline void PSPromotionManager::claim_or_forward_depth(T* p) {
60 assert(PSScavenge::should_scavenge(p, true), "revisiting object?");
61 assert(Universe::heap()->kind() == CollectedHeap::ParallelScavengeHeap,
62 "Sanity");
63 assert(Universe::heap()->is_in(p), "pointer outside heap");
64
65 claim_or_forward_internal_depth(p);
66 }
67
68 //
69 // This method is pretty bulky. It would be nice to split it up
70 // into smaller submethods, but we need to be careful not to hurt
71 // performance.
72 //
73 template<bool promote_immediately>
74 oop PSPromotionManager::copy_to_survivor_space(oop o) {
75 assert(PSScavenge::should_scavenge(&o), "Sanity");
76
77 oop new_obj = NULL;
78
79 // NOTE! We must be very careful with any methods that access the mark
80 // in o. There may be multiple threads racing on it, and it may be forwarded
81 // at any time. Do not use oop methods for accessing the mark!
82 markOop test_mark = o->mark();
83
84 // The same test as "o->is_forwarded()"
85 if (!test_mark->is_marked()) {
86 bool new_obj_is_tenured = false;
87 size_t new_obj_size = o->size();
88
89 if (!promote_immediately) {
90 // Find the objects age, MT safe.
91 uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
92 test_mark->displaced_mark_helper()->age() : test_mark->age();
93
94 // Try allocating obj in to-space (unless too old)
95 if (age < PSScavenge::tenuring_threshold()) {
96 new_obj = (oop) _young_lab.allocate(new_obj_size);
97 if (new_obj == NULL && !_young_gen_is_full) {
98 // Do we allocate directly, or flush and refill?
99 if (new_obj_size > (YoungPLABSize / 2)) {
100 // Allocate this object directly
101 new_obj = (oop)young_space()->cas_allocate(new_obj_size);
102 } else {
103 // Flush and fill
104 _young_lab.flush();
105
106 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
107 if (lab_base != NULL) {
108 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
109 // Try the young lab allocation again.
110 new_obj = (oop) _young_lab.allocate(new_obj_size);
111 } else {
112 _young_gen_is_full = true;
113 }
114 }
115 }
116 }
117 }
118
119 // Otherwise try allocating obj tenured
120 if (new_obj == NULL) {
121 #ifndef PRODUCT
122 if (Universe::heap()->promotion_should_fail()) {
123 return oop_promotion_failed(o, test_mark);
124 }
125 #endif // #ifndef PRODUCT
126
127 new_obj = (oop) _old_lab.allocate(new_obj_size);
128 new_obj_is_tenured = true;
129
130 if (new_obj == NULL) {
131 if (!_old_gen_is_full) {
132 // Do we allocate directly, or flush and refill?
133 if (new_obj_size > (OldPLABSize / 2)) {
134 // Allocate this object directly
135 new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
136 } else {
137 // Flush and fill
138 _old_lab.flush();
139
140 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
141 if(lab_base != NULL) {
142 #ifdef ASSERT
143 // Delay the initialization of the promotion lab (plab).
144 // This exposes uninitialized plabs to card table processing.
145 if (GCWorkerDelayMillis > 0) {
146 os::sleep(Thread::current(), GCWorkerDelayMillis, false);
147 }
148 #endif
149 _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
150 // Try the old lab allocation again.
151 new_obj = (oop) _old_lab.allocate(new_obj_size);
152 }
153 }
154 }
155
156 // This is the promotion failed test, and code handling.
157 // The code belongs here for two reasons. It is slightly
158 // different than the code below, and cannot share the
159 // CAS testing code. Keeping the code here also minimizes
160 // the impact on the common case fast path code.
161
162 if (new_obj == NULL) {
163 _old_gen_is_full = true;
164 return oop_promotion_failed(o, test_mark);
165 }
166 }
167 }
168
169 assert(new_obj != NULL, "allocation should have succeeded");
170
171 // Copy obj
172 Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
173
174 // Now we have to CAS in the header.
175 if (o->cas_forward_to(new_obj, test_mark)) {
176 // We won any races, we "own" this object.
177 assert(new_obj == o->forwardee(), "Sanity");
178
179 // Increment age if obj still in new generation. Now that
180 // we're dealing with a markOop that cannot change, it is
181 // okay to use the non mt safe oop methods.
182 if (!new_obj_is_tenured) {
183 new_obj->incr_age();
184 assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
185 }
186
187 // Do the size comparison first with new_obj_size, which we
188 // already have. Hopefully, only a few objects are larger than
189 // _min_array_size_for_chunking, and most of them will be arrays.
190 // So, the is->objArray() test would be very infrequent.
191 if (new_obj_size > _min_array_size_for_chunking &&
192 new_obj->is_objArray() &&
193 PSChunkLargeArrays) {
194 // we'll chunk it
195 oop* const masked_o = mask_chunked_array_oop(o);
196 push_depth(masked_o);
197 TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
198 } else {
199 // we'll just push its contents
200 new_obj->push_contents(this);
201 }
202 } else {
203 // We lost, someone else "owns" this object
204 guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
205
206 // Try to deallocate the space. If it was directly allocated we cannot
207 // deallocate it, so we have to test. If the deallocation fails,
208 // overwrite with a filler object.
209 if (new_obj_is_tenured) {
210 if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
211 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
212 }
213 } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
214 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
215 }
216
217 // don't update this before the unallocation!
218 new_obj = o->forwardee();
219 }
220 } else {
221 assert(o->is_forwarded(), "Sanity");
222 new_obj = o->forwardee();
223 }
224
225 #ifndef PRODUCT
226 // This code must come after the CAS test, or it will print incorrect
227 // information.
228 if (TraceScavenge) {
229 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
230 PSScavenge::should_scavenge(&new_obj) ? "copying" : "tenuring",
231 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
232 }
233 #endif
234
235 return new_obj;
236 }
237
238
239 inline void PSPromotionManager::process_popped_location_depth(StarTask p) {
240 if (is_oop_masked(p)) {
241 assert(PSChunkLargeArrays, "invariant");
242 oop const old = unmask_chunked_array_oop(p);
243 process_array_chunk(old);
244 } else {
245 if (p.is_narrow()) {
246 assert(UseCompressedOops, "Error");
247 PSScavenge::copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(this, p);
248 } else {
249 PSScavenge::copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(this, p);
250 }
251 }
252 }
253
254 #if TASKQUEUE_STATS
255 void PSPromotionManager::record_steal(StarTask& p) {
256 if (is_oop_masked(p)) {
257 ++_masked_steals;
258 }
259 }
260 #endif // TASKQUEUE_STATS
261
262 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP