1 /*
2 * Copyright (c) 2002, 2013, 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
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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 #include "oops/oop.psgc.inline.hpp"
32
33 inline PSPromotionManager* PSPromotionManager::manager_array(int index) {
34 assert(_manager_array != NULL, "access of NULL manager_array");
35 assert(index >= 0 && index <= (int)ParallelGCThreads, "out of range manager_array access");
36 return &_manager_array[index];
37 }
38
39 template <class T>
40 inline void PSPromotionManager::claim_or_forward_internal_depth(T* p) {
41 if (p != NULL) { // XXX: error if p != NULL here
42 oop o = oopDesc::load_decode_heap_oop_not_null(p);
43 if (o->is_forwarded()) {
44 o = o->forwardee();
45 // Card mark
46 if (PSScavenge::is_obj_in_young(o)) {
47 PSScavenge::card_table()->inline_write_ref_field_gc(p, o);
48 }
49 oopDesc::encode_store_heap_oop_not_null(p, o);
50 } else {
51 push_depth(p);
52 }
53 }
54 }
55
56 template <class T>
57 inline void PSPromotionManager::claim_or_forward_depth(T* p) {
58 assert(PSScavenge::should_scavenge(p, true), "revisiting object?");
59 assert(Universe::heap()->kind() == CollectedHeap::ParallelScavengeHeap,
60 "Sanity");
61 assert(Universe::heap()->is_in(p), "pointer outside heap");
62
63 claim_or_forward_internal_depth(p);
64 }
65
66 //
67 // This method is pretty bulky. It would be nice to split it up
68 // into smaller submethods, but we need to be careful not to hurt
69 // performance.
70 //
71 template<bool promote_immediately>
72 oop PSPromotionManager::copy_to_survivor_space(oop o) {
73 assert(PSScavenge::should_scavenge(&o), "Sanity");
74
75 oop new_obj = NULL;
76
77 // NOTE! We must be very careful with any methods that access the mark
78 // in o. There may be multiple threads racing on it, and it may be forwarded
79 // at any time. Do not use oop methods for accessing the mark!
80 markOop test_mark = o->mark();
81
82 // The same test as "o->is_forwarded()"
83 if (!test_mark->is_marked()) {
84 bool new_obj_is_tenured = false;
85 size_t new_obj_size = o->size();
86
87 if (!promote_immediately) {
88 // Find the objects age, MT safe.
89 uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
90 test_mark->displaced_mark_helper()->age() : test_mark->age();
91
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 } else {
101 // Flush and fill
102 _young_lab.flush();
103
104 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
105 if (lab_base != NULL) {
106 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
107 // Try the young lab allocation again.
108 new_obj = (oop) _young_lab.allocate(new_obj_size);
109 } else {
110 _young_gen_is_full = true;
111 }
112 }
113 }
114 }
115 }
116
117 // Otherwise try allocating obj tenured
118 if (new_obj == NULL) {
119 #ifndef PRODUCT
120 if (Universe::heap()->promotion_should_fail()) {
121 return oop_promotion_failed(o, test_mark);
122 }
123 #endif // #ifndef PRODUCT
124
125 new_obj = (oop) _old_lab.allocate(new_obj_size);
126 new_obj_is_tenured = true;
127
128 if (new_obj == NULL) {
129 if (!_old_gen_is_full) {
130 // Do we allocate directly, or flush and refill?
131 if (new_obj_size > (OldPLABSize / 2)) {
132 // Allocate this object directly
133 new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
134 } else {
135 // Flush and fill
136 _old_lab.flush();
137
138 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
139 if(lab_base != NULL) {
140 #ifdef ASSERT
141 // Delay the initialization of the promotion lab (plab).
142 // This exposes uninitialized plabs to card table processing.
143 if (GCWorkerDelayMillis > 0) {
144 os::sleep(Thread::current(), GCWorkerDelayMillis, false);
145 }
146 #endif
147 _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
148 // Try the old lab allocation again.
149 new_obj = (oop) _old_lab.allocate(new_obj_size);
150 }
151 }
152 }
153
154 // This is the promotion failed test, and code handling.
155 // The code belongs here for two reasons. It is slightly
156 // different than the code below, and cannot share the
157 // CAS testing code. Keeping the code here also minimizes
158 // the impact on the common case fast path code.
159
160 if (new_obj == NULL) {
161 _old_gen_is_full = true;
162 return oop_promotion_failed(o, test_mark);
163 }
164 }
165 }
166
167 assert(new_obj != NULL, "allocation should have succeeded");
168
169 // Copy obj
170 Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
171
172 // Now we have to CAS in the header.
173 if (o->cas_forward_to(new_obj, test_mark)) {
174 // We won any races, we "own" this object.
175 assert(new_obj == o->forwardee(), "Sanity");
176
177 // Increment age if obj still in new generation. Now that
178 // we're dealing with a markOop that cannot change, it is
179 // okay to use the non mt safe oop methods.
180 if (!new_obj_is_tenured) {
181 new_obj->incr_age();
182 assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
183 }
184
185 // Do the size comparison first with new_obj_size, which we
186 // already have. Hopefully, only a few objects are larger than
187 // _min_array_size_for_chunking, and most of them will be arrays.
188 // So, the is->objArray() test would be very infrequent.
189 if (new_obj_size > _min_array_size_for_chunking &&
190 new_obj->is_objArray() &&
191 PSChunkLargeArrays) {
192 // we'll chunk it
193 oop* const masked_o = mask_chunked_array_oop(o);
194 push_depth(masked_o);
195 TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
196 } else {
197 // we'll just push its contents
198 new_obj->push_contents(this);
199 }
200 } else {
201 // We lost, someone else "owns" this object
202 guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
203
204 // Try to deallocate the space. If it was directly allocated we cannot
205 // deallocate it, so we have to test. If the deallocation fails,
206 // overwrite with a filler object.
207 if (new_obj_is_tenured) {
208 if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
209 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
210 }
211 } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
212 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
213 }
214
215 // don't update this before the unallocation!
216 new_obj = o->forwardee();
217 }
218 } else {
219 assert(o->is_forwarded(), "Sanity");
220 new_obj = o->forwardee();
221 }
222
223 #ifndef PRODUCT
224 // This code must come after the CAS test, or it will print incorrect
225 // information.
226 if (TraceScavenge) {
227 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
228 PSScavenge::should_scavenge(&new_obj) ? "copying" : "tenuring",
229 new_obj->klass()->internal_name(), (void *)o, (void *)new_obj, new_obj->size());
230 }
231 #endif
232
233 return new_obj;
234 }
235
236
237 inline void PSPromotionManager::process_popped_location_depth(StarTask p) {
238 if (is_oop_masked(p)) {
239 assert(PSChunkLargeArrays, "invariant");
240 oop const old = unmask_chunked_array_oop(p);
241 process_array_chunk(old);
242 } else {
243 if (p.is_narrow()) {
244 assert(UseCompressedOops, "Error");
245 PSScavenge::copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(this, p);
246 } else {
247 PSScavenge::copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(this, p);
248 }
249 }
250 }
251
252 #if TASKQUEUE_STATS
253 void PSPromotionManager::record_steal(StarTask& p) {
254 if (is_oop_masked(p)) {
255 ++_masked_steals;
256 }
257 }
258 #endif // TASKQUEUE_STATS
259
260 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP