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 "oops/oop.psgc.inline.hpp"
33
34 inline PSPromotionManager* PSPromotionManager::manager_array(int index) {
35 assert(_manager_array != NULL, "access of NULL manager_array");
36 assert(index >= 0 && index <= (int)ParallelGCThreads, "out of range manager_array access");
37 return &_manager_array[index];
38 }
39
40 template <class T>
41 inline void PSPromotionManager::claim_or_forward_internal_depth(T* p) {
42 if (p != NULL) { // XXX: error if p != NULL here
43 oop o = oopDesc::load_decode_heap_oop_not_null(p);
44 if (o->is_forwarded()) {
45 o = o->forwardee();
46 // Card mark
47 if (PSScavenge::is_obj_in_young(o)) {
48 PSScavenge::card_table()->inline_write_ref_field_gc(p, o);
49 }
50 oopDesc::encode_store_heap_oop_not_null(p, o);
51 } else {
52 push_depth(p);
53 }
54 }
55 }
56
57 template <class T>
58 inline void PSPromotionManager::claim_or_forward_depth(T* p) {
59 assert(PSScavenge::should_scavenge(p, true), "revisiting object?");
60 assert(Universe::heap()->kind() == CollectedHeap::ParallelScavengeHeap,
61 "Sanity");
62 assert(Universe::heap()->is_in(p), "pointer outside heap");
63
64 claim_or_forward_internal_depth(p);
65 }
66
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
171 Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
172
173 // Now we have to CAS in the header.
174 if (o->cas_forward_to(new_obj, test_mark)) {
175 // We won any races, we "own" this object.
176 assert(new_obj == o->forwardee(), "Sanity");
177
178 // Increment age if obj still in new generation. Now that
179 // we're dealing with a markOop that cannot change, it is
180 // okay to use the non mt safe oop methods.
181 if (!new_obj_is_tenured) {
182 new_obj->incr_age();
183 assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
184 }
185
186 // Do the size comparison first with new_obj_size, which we
187 // already have. Hopefully, only a few objects are larger than
188 // _min_array_size_for_chunking, and most of them will be arrays.
189 // So, the is->objArray() test would be very infrequent.
190 if (new_obj_size > _min_array_size_for_chunking &&
191 new_obj->is_objArray() &&
192 PSChunkLargeArrays) {
193 // we'll chunk it
194 oop* const masked_o = mask_chunked_array_oop(o);
195 push_depth(masked_o);
196 TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
197 } else {
198 // we'll just push its contents
199 new_obj->push_contents(this);
200 }
201 } else {
202 // We lost, someone else "owns" this object
203 guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
204
205 // Try to deallocate the space. If it was directly allocated we cannot
206 // deallocate it, so we have to test. If the deallocation fails,
207 // overwrite with a filler object.
208 if (new_obj_is_tenured) {
209 if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
210 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
211 }
212 } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
213 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
214 }
215
216 // don't update this before the unallocation!
217 new_obj = o->forwardee();
218 }
219 } else {
220 assert(o->is_forwarded(), "Sanity");
221 new_obj = o->forwardee();
222 }
223
224 #ifndef PRODUCT
225 // This code must come after the CAS test, or it will print incorrect
226 // information.
227 if (TraceScavenge) {
228 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
229 PSScavenge::should_scavenge(&new_obj) ? "copying" : "tenuring",
230 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
231 }
232 #endif
233
234 return new_obj;
235 }
236
237
238 inline void PSPromotionManager::process_popped_location_depth(StarTask p) {
239 if (is_oop_masked(p)) {
240 assert(PSChunkLargeArrays, "invariant");
241 oop const old = unmask_chunked_array_oop(p);
242 process_array_chunk(old);
243 } else {
244 if (p.is_narrow()) {
245 assert(UseCompressedOops, "Error");
246 PSScavenge::copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(this, p);
247 } else {
248 PSScavenge::copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(this, p);
249 }
250 }
251 }
252
253 #if TASKQUEUE_STATS
254 void PSPromotionManager::record_steal(StarTask& p) {
255 if (is_oop_masked(p)) {
256 ++_masked_steals;
257 }
258 }
259 #endif // TASKQUEUE_STATS
260
261 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP