1 /*
2 * Copyright (c) 2002, 2015, 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
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7 * published by the Free Software Foundation.
8 *
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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).
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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/parallelScavengeHeap.hpp"
29 #include "gc_implementation/parallelScavenge/psOldGen.hpp"
30 #include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
31 #include "gc_implementation/parallelScavenge/psPromotionLAB.inline.hpp"
32 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
33 #include "oops/oop.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(should_scavenge(p, true), "revisiting object?");
61 assert(ParallelScavengeHeap::heap()->is_in(p), "pointer outside heap");
62
63 claim_or_forward_internal_depth(p);
64 }
65
66 inline void PSPromotionManager::promotion_trace_event(oop new_obj, oop old_obj,
67 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) {
75 // Promotion of object through newly allocated PLAB
76 if (gc_tracer->should_report_promotion_in_new_plab_event()) {
77 size_t obj_bytes = obj_size * HeapWordSize;
78 size_t lab_size = lab->capacity();
79 gc_tracer->report_promotion_in_new_plab_event(old_obj->klass(), obj_bytes,
80 age, tenured, lab_size);
81 }
82 } else {
83 // Promotion of object directly to heap
84 if (gc_tracer->should_report_promotion_outside_plab_event()) {
85 size_t obj_bytes = obj_size * HeapWordSize;
86 gc_tracer->report_promotion_outside_plab_event(old_obj->klass(), obj_bytes,
87 age, tenured);
88 }
89 }
90 }
91 }
92
93 inline void PSPromotionManager::push_contents(oop obj) {
94 obj->ps_push_contents(this);
95 }
96 //
97 // This method is pretty bulky. It would be nice to split it up
98 // into smaller submethods, but we need to be careful not to hurt
99 // performance.
100 //
101 template<bool promote_immediately>
102 oop PSPromotionManager::copy_to_survivor_space(oop o) {
103 assert(should_scavenge(&o), "Sanity");
104
105 oop new_obj = NULL;
106
107 // NOTE! We must be very careful with any methods that access the mark
108 // in o. There may be multiple threads racing on it, and it may be forwarded
109 // at any time. Do not use oop methods for accessing the mark!
110 markOop test_mark = o->mark();
111
112 // The same test as "o->is_forwarded()"
113 if (!test_mark->is_marked()) {
114 bool new_obj_is_tenured = false;
115 size_t new_obj_size = o->size();
116
117 // Find the objects age, MT safe.
118 uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
119 test_mark->displaced_mark_helper()->age() : test_mark->age();
120
121 if (!promote_immediately) {
122 // Try allocating obj in to-space (unless too old)
123 if (age < PSScavenge::tenuring_threshold()) {
124 new_obj = (oop) _young_lab.allocate(new_obj_size);
125 if (new_obj == NULL && !_young_gen_is_full) {
126 // Do we allocate directly, or flush and refill?
127 if (new_obj_size > (YoungPLABSize / 2)) {
128 // Allocate this object directly
129 new_obj = (oop)young_space()->cas_allocate(new_obj_size);
130 promotion_trace_event(new_obj, o, new_obj_size, age, false, NULL);
131 } else {
132 // Flush and fill
133 _young_lab.flush();
134
135 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
136 if (lab_base != NULL) {
137 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
138 // Try the young lab allocation again.
139 new_obj = (oop) _young_lab.allocate(new_obj_size);
140 promotion_trace_event(new_obj, o, new_obj_size, age, false, &_young_lab);
141 } else {
142 _young_gen_is_full = true;
143 }
144 }
145 }
146 }
147 }
148
149 // Otherwise try allocating obj tenured
150 if (new_obj == NULL) {
151 #ifndef PRODUCT
152 if (ParallelScavengeHeap::heap()->promotion_should_fail()) {
153 return oop_promotion_failed(o, test_mark);
154 }
155 #endif // #ifndef PRODUCT
156
157 new_obj = (oop) _old_lab.allocate(new_obj_size);
158 new_obj_is_tenured = true;
159
160 if (new_obj == NULL) {
161 if (!_old_gen_is_full) {
162 // Do we allocate directly, or flush and refill?
163 if (new_obj_size > (OldPLABSize / 2)) {
164 // Allocate this object directly
165 new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
166 promotion_trace_event(new_obj, o, new_obj_size, age, true, NULL);
167 } else {
168 // Flush and fill
169 _old_lab.flush();
170
171 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
172 if(lab_base != NULL) {
173 #ifdef ASSERT
174 // Delay the initialization of the promotion lab (plab).
175 // This exposes uninitialized plabs to card table processing.
176 if (GCWorkerDelayMillis > 0) {
177 os::sleep(Thread::current(), GCWorkerDelayMillis, false);
178 }
179 #endif
180 _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
181 // Try the old lab allocation again.
182 new_obj = (oop) _old_lab.allocate(new_obj_size);
183 promotion_trace_event(new_obj, o, new_obj_size, age, true, &_old_lab);
184 }
185 }
186 }
187
188 // This is the promotion failed test, and code handling.
189 // The code belongs here for two reasons. It is slightly
190 // different than the code below, and cannot share the
191 // CAS testing code. Keeping the code here also minimizes
192 // the impact on the common case fast path code.
193
194 if (new_obj == NULL) {
195 _old_gen_is_full = true;
196 return oop_promotion_failed(o, test_mark);
197 }
198 }
199 }
200
201 assert(new_obj != NULL, "allocation should have succeeded");
202
203 // Copy obj
204 Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
205
206 // Now we have to CAS in the header.
207 if (o->cas_forward_to(new_obj, test_mark)) {
208 // We won any races, we "own" this object.
209 assert(new_obj == o->forwardee(), "Sanity");
210
211 // Increment age if obj still in new generation. Now that
212 // we're dealing with a markOop that cannot change, it is
213 // okay to use the non mt safe oop methods.
214 if (!new_obj_is_tenured) {
215 new_obj->incr_age();
216 assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
217 }
218
219 // Do the size comparison first with new_obj_size, which we
220 // already have. Hopefully, only a few objects are larger than
221 // _min_array_size_for_chunking, and most of them will be arrays.
222 // So, the is->objArray() test would be very infrequent.
223 if (new_obj_size > _min_array_size_for_chunking &&
224 new_obj->is_objArray() &&
225 PSChunkLargeArrays) {
226 // we'll chunk it
227 oop* const masked_o = mask_chunked_array_oop(o);
228 push_depth(masked_o);
229 TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
230 } else {
231 // we'll just push its contents
232 push_contents(new_obj);
233 }
234 } else {
235 // We lost, someone else "owns" this object
236 guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
237
238 // Try to deallocate the space. If it was directly allocated we cannot
239 // deallocate it, so we have to test. If the deallocation fails,
240 // overwrite with a filler object.
241 if (new_obj_is_tenured) {
242 if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
243 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
244 }
245 } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
246 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
247 }
248
249 // don't update this before the unallocation!
250 new_obj = o->forwardee();
251 }
252 } else {
253 assert(o->is_forwarded(), "Sanity");
254 new_obj = o->forwardee();
255 }
256
257 #ifndef PRODUCT
258 // This code must come after the CAS test, or it will print incorrect
259 // information.
260 if (TraceScavenge) {
261 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
262 should_scavenge(&new_obj) ? "copying" : "tenuring",
263 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
264 }
265 #endif
266
267 return new_obj;
268 }
269
270 // Attempt to "claim" oop at p via CAS, push the new obj if successful
271 // This version tests the oop* to make sure it is within the heap before
272 // attempting marking.
273 template <class T, bool promote_immediately>
274 inline void PSPromotionManager::copy_and_push_safe_barrier(T* p) {
275 assert(should_scavenge(p, true), "revisiting object?");
276
277 oop o = oopDesc::load_decode_heap_oop_not_null(p);
278 oop new_obj = o->is_forwarded()
279 ? o->forwardee()
280 : copy_to_survivor_space<promote_immediately>(o);
281
282 #ifndef PRODUCT
283 // This code must come after the CAS test, or it will print incorrect
284 // information.
285 if (TraceScavenge && o->is_forwarded()) {
286 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
287 "forwarding",
288 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
289 }
290 #endif
291
292 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
293
294 // We cannot mark without test, as some code passes us pointers
295 // that are outside the heap. These pointers are either from roots
296 // or from metadata.
297 if ((!PSScavenge::is_obj_in_young((HeapWord*)p)) &&
298 ParallelScavengeHeap::heap()->is_in_reserved(p)) {
299 if (PSScavenge::is_obj_in_young(new_obj)) {
300 PSScavenge::card_table()->inline_write_ref_field_gc(p, new_obj);
301 }
302 }
303 }
304
305 inline void PSPromotionManager::process_popped_location_depth(StarTask p) {
306 if (is_oop_masked(p)) {
307 assert(PSChunkLargeArrays, "invariant");
308 oop const old = unmask_chunked_array_oop(p);
309 process_array_chunk(old);
310 } else {
311 if (p.is_narrow()) {
312 assert(UseCompressedOops, "Error");
313 copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(p);
314 } else {
315 copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(p);
316 }
317 }
318 }
319
320 #if TASKQUEUE_STATS
321 void PSPromotionManager::record_steal(StarTask& p) {
322 if (is_oop_masked(p)) {
323 ++_masked_steals;
324 }
325 }
326 #endif // TASKQUEUE_STATS
327
328 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP