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.
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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,
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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 inline void PSPromotionManager::promotion_trace_event(oop new_obj, oop old_obj, size_t obj_size,
68 uint age, bool tenured,
69 const PSPromotionLAB* lab) {
70 // Skip if memory allocation failed
71 if (new_obj != NULL) {
72 const ParallelScavengeTracer* gc_tracer = PSScavenge::gc_tracer();
73
74 if (lab != NULL && gc_tracer->should_report_promotion_in_new_plab_event()) {
75 // Promotion of small object in new PLAB
76 size_t obj_bytes = obj_size * HeapWordSize;
77 size_t lab_size = lab->capacity();
78 gc_tracer->report_promotion_in_new_plab_event(old_obj->klass(), obj_bytes, age, tenured, lab_size);
79
80 } else if (gc_tracer->should_report_promotion_outside_plab_event()) {
81 // Promotion of object directly to heap without PLAB
82 size_t obj_bytes = obj_size * HeapWordSize;
83 gc_tracer->report_promotion_outside_plab_event(old_obj->klass(), obj_bytes, age, tenured);
84 }
85 }
86 }
87
88 //
89 // This method is pretty bulky. It would be nice to split it up
90 // into smaller submethods, but we need to be careful not to hurt
91 // performance.
92 //
93 template<bool promote_immediately>
94 oop PSPromotionManager::copy_to_survivor_space(oop o) {
95 assert(PSScavenge::should_scavenge(&o), "Sanity");
96
97 oop new_obj = NULL;
98
99 // NOTE! We must be very careful with any methods that access the mark
100 // in o. There may be multiple threads racing on it, and it may be forwarded
101 // at any time. Do not use oop methods for accessing the mark!
102 markOop test_mark = o->mark();
103
104 // The same test as "o->is_forwarded()"
105 if (!test_mark->is_marked()) {
106 bool new_obj_is_tenured = false;
107 size_t new_obj_size = o->size();
108
109 // Find the objects age, MT safe.
110 uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
111 test_mark->displaced_mark_helper()->age() : test_mark->age();
112
113 if (!promote_immediately) {
114 // Try allocating obj in to-space (unless too old)
115 if (age < PSScavenge::tenuring_threshold()) {
116 new_obj = (oop) _young_lab.allocate(new_obj_size);
117 if (new_obj == NULL && !_young_gen_is_full) {
118 // Do we allocate directly, or flush and refill?
119 if (new_obj_size > (YoungPLABSize / 2)) {
120 // Allocate this object directly
121 new_obj = (oop)young_space()->cas_allocate(new_obj_size);
122 promotion_trace_event(new_obj, o, new_obj_size, age, false, NULL);
123 } else {
124 // Flush and fill
125 _young_lab.flush();
126
127 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
128 if (lab_base != NULL) {
129 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
130 // Try the young lab allocation again.
131 new_obj = (oop) _young_lab.allocate(new_obj_size);
132 promotion_trace_event(new_obj, o, new_obj_size, age, false, &_young_lab);
133 } else {
134 _young_gen_is_full = true;
135 }
136 }
137 }
138 }
139 }
140
141 // Otherwise try allocating obj tenured
142 if (new_obj == NULL) {
143 #ifndef PRODUCT
144 if (Universe::heap()->promotion_should_fail()) {
145 return oop_promotion_failed(o, test_mark);
146 }
147 #endif // #ifndef PRODUCT
148
149 new_obj = (oop) _old_lab.allocate(new_obj_size);
150 new_obj_is_tenured = true;
151
152 if (new_obj == NULL) {
153 if (!_old_gen_is_full) {
154 // Do we allocate directly, or flush and refill?
155 if (new_obj_size > (OldPLABSize / 2)) {
156 // Allocate this object directly
157 new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
158 promotion_trace_event(new_obj, o, new_obj_size, age, true, NULL);
159 } else {
160 // Flush and fill
161 _old_lab.flush();
162
163 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
164 if(lab_base != NULL) {
165 #ifdef ASSERT
166 // Delay the initialization of the promotion lab (plab).
167 // This exposes uninitialized plabs to card table processing.
168 if (GCWorkerDelayMillis > 0) {
169 os::sleep(Thread::current(), GCWorkerDelayMillis, false);
170 }
171 #endif
172 _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
173 // Try the old lab allocation again.
174 new_obj = (oop) _old_lab.allocate(new_obj_size);
175 promotion_trace_event(new_obj, o, new_obj_size, age, true, &_old_lab);
176 }
177 }
178 }
179
180 // This is the promotion failed test, and code handling.
181 // The code belongs here for two reasons. It is slightly
182 // different than the code below, and cannot share the
183 // CAS testing code. Keeping the code here also minimizes
184 // the impact on the common case fast path code.
185
186 if (new_obj == NULL) {
187 _old_gen_is_full = true;
188 return oop_promotion_failed(o, test_mark);
189 }
190 }
191 }
192
193 assert(new_obj != NULL, "allocation should have succeeded");
194
195 // Copy obj
196 Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
197
198 // Now we have to CAS in the header.
199 if (o->cas_forward_to(new_obj, test_mark)) {
200 // We won any races, we "own" this object.
201 assert(new_obj == o->forwardee(), "Sanity");
202
203 // Increment age if obj still in new generation. Now that
204 // we're dealing with a markOop that cannot change, it is
205 // okay to use the non mt safe oop methods.
206 if (!new_obj_is_tenured) {
207 new_obj->incr_age();
208 assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
209 }
210
211 // Do the size comparison first with new_obj_size, which we
212 // already have. Hopefully, only a few objects are larger than
213 // _min_array_size_for_chunking, and most of them will be arrays.
214 // So, the is->objArray() test would be very infrequent.
215 if (new_obj_size > _min_array_size_for_chunking &&
216 new_obj->is_objArray() &&
217 PSChunkLargeArrays) {
218 // we'll chunk it
219 oop* const masked_o = mask_chunked_array_oop(o);
220 push_depth(masked_o);
221 TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
222 } else {
223 // we'll just push its contents
224 new_obj->push_contents(this);
225 }
226 } else {
227 // We lost, someone else "owns" this object
228 guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
229
230 // Try to deallocate the space. If it was directly allocated we cannot
231 // deallocate it, so we have to test. If the deallocation fails,
232 // overwrite with a filler object.
233 if (new_obj_is_tenured) {
234 if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
235 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
236 }
237 } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
238 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
239 }
240
241 // don't update this before the unallocation!
242 new_obj = o->forwardee();
243 }
244 } else {
245 assert(o->is_forwarded(), "Sanity");
246 new_obj = o->forwardee();
247 }
248
249 #ifndef PRODUCT
250 // This code must come after the CAS test, or it will print incorrect
251 // information.
252 if (TraceScavenge) {
253 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
254 PSScavenge::should_scavenge(&new_obj) ? "copying" : "tenuring",
255 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
256 }
257 #endif
258
259 return new_obj;
260 }
261
262
263 inline void PSPromotionManager::process_popped_location_depth(StarTask p) {
264 if (is_oop_masked(p)) {
265 assert(PSChunkLargeArrays, "invariant");
266 oop const old = unmask_chunked_array_oop(p);
267 process_array_chunk(old);
268 } else {
269 if (p.is_narrow()) {
270 assert(UseCompressedOops, "Error");
271 PSScavenge::copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(this, p);
272 } else {
273 PSScavenge::copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(this, p);
274 }
275 }
276 }
277
278 #if TASKQUEUE_STATS
279 void PSPromotionManager::record_steal(StarTask& p) {
280 if (is_oop_masked(p)) {
281 ++_masked_steals;
282 }
283 }
284 #endif // TASKQUEUE_STATS
285
286 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP