1 /*
2 * Copyright (c) 2002, 2018, 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_PARALLEL_PSPROMOTIONMANAGER_INLINE_HPP
26 #define SHARE_VM_GC_PARALLEL_PSPROMOTIONMANAGER_INLINE_HPP
27
28 #include "gc/parallel/parallelScavengeHeap.hpp"
29 #include "gc/parallel/parMarkBitMap.inline.hpp"
30 #include "gc/parallel/psOldGen.hpp"
31 #include "gc/parallel/psPromotionLAB.inline.hpp"
32 #include "gc/parallel/psPromotionManager.hpp"
33 #include "gc/parallel/psScavenge.hpp"
34 #include "gc/shared/taskqueue.inline.hpp"
35 #include "logging/log.hpp"
36 #include "oops/oop.inline.hpp"
37
38 inline PSPromotionManager* PSPromotionManager::manager_array(uint index) {
39 assert(_manager_array != NULL, "access of NULL manager_array");
40 assert(index <= ParallelGCThreads, "out of range manager_array access");
41 return &_manager_array[index];
42 }
43
44 template <class T>
45 inline void PSPromotionManager::push_depth(T* p) {
46 claimed_stack_depth()->push(p);
47 }
48
49 template <class T>
50 inline void PSPromotionManager::claim_or_forward_internal_depth(T* p) {
51 if (p != NULL) { // XXX: error if p != NULL here
52 oop o = oopDesc::load_decode_heap_oop_not_null(p);
53 if (o->is_forwarded()) {
54 o = o->forwardee();
55 // Card mark
56 if (PSScavenge::is_obj_in_young(o)) {
57 PSScavenge::card_table()->inline_write_ref_field_gc(p, o);
58 }
59 oopDesc::encode_store_heap_oop_not_null(p, o);
60 } else {
61 push_depth(p);
62 }
63 }
64 }
65
66 template <class T>
67 inline void PSPromotionManager::claim_or_forward_depth(T* p) {
68 assert(should_scavenge(p, true), "revisiting object?");
69 assert(ParallelScavengeHeap::heap()->is_in(p), "pointer outside heap");
70
71 claim_or_forward_internal_depth(p);
72 }
73
74 inline void PSPromotionManager::promotion_trace_event(oop new_obj, oop old_obj,
75 size_t obj_size,
76 uint age, bool tenured,
77 const PSPromotionLAB* lab) {
78 // Skip if memory allocation failed
79 if (new_obj != NULL) {
80 const ParallelScavengeTracer* gc_tracer = PSScavenge::gc_tracer();
81
82 if (lab != NULL) {
83 // Promotion of object through newly allocated PLAB
84 if (gc_tracer->should_report_promotion_in_new_plab_event()) {
85 size_t obj_bytes = obj_size * HeapWordSize;
86 size_t lab_size = lab->capacity();
87 gc_tracer->report_promotion_in_new_plab_event(old_obj->klass(), obj_bytes,
88 age, tenured, lab_size);
89 }
90 } else {
91 // Promotion of object directly to heap
92 if (gc_tracer->should_report_promotion_outside_plab_event()) {
93 size_t obj_bytes = obj_size * HeapWordSize;
94 gc_tracer->report_promotion_outside_plab_event(old_obj->klass(), obj_bytes,
95 age, tenured);
96 }
97 }
98 }
99 }
100
101 inline void PSPromotionManager::push_contents(oop obj) {
102 obj->ps_push_contents(this);
103 }
104 //
105 // This method is pretty bulky. It would be nice to split it up
106 // into smaller submethods, but we need to be careful not to hurt
107 // performance.
108 //
109 template<bool promote_immediately>
110 inline oop PSPromotionManager::copy_to_survivor_space(oop o) {
111 assert(should_scavenge(&o), "Sanity");
112
113 oop new_obj = NULL;
114
115 // NOTE! We must be very careful with any methods that access the mark
116 // in o. There may be multiple threads racing on it, and it may be forwarded
117 // at any time. Do not use oop methods for accessing the mark!
118 markOop test_mark = o->mark_raw();
119
120 // The same test as "o->is_forwarded()"
121 if (!test_mark->is_marked()) {
122 bool new_obj_is_tenured = false;
123 size_t new_obj_size = o->size();
124
125 // Find the objects age, MT safe.
126 uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
127 test_mark->displaced_mark_helper()->age() : test_mark->age();
128
129 if (!promote_immediately) {
130 // Try allocating obj in to-space (unless too old)
131 if (age < PSScavenge::tenuring_threshold()) {
132 new_obj = (oop) _young_lab.allocate(new_obj_size);
133 if (new_obj == NULL && !_young_gen_is_full) {
134 // Do we allocate directly, or flush and refill?
135 if (new_obj_size > (YoungPLABSize / 2)) {
136 // Allocate this object directly
137 new_obj = (oop)young_space()->cas_allocate(new_obj_size);
138 promotion_trace_event(new_obj, o, new_obj_size, age, false, NULL);
139 } else {
140 // Flush and fill
141 _young_lab.flush();
142
143 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
144 if (lab_base != NULL) {
145 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
146 // Try the young lab allocation again.
147 new_obj = (oop) _young_lab.allocate(new_obj_size);
148 promotion_trace_event(new_obj, o, new_obj_size, age, false, &_young_lab);
149 } else {
150 _young_gen_is_full = true;
151 }
152 }
153 }
154 }
155 }
156
157 // Otherwise try allocating obj tenured
158 if (new_obj == NULL) {
159 #ifndef PRODUCT
160 if (ParallelScavengeHeap::heap()->promotion_should_fail()) {
161 return oop_promotion_failed(o, test_mark);
162 }
163 #endif // #ifndef PRODUCT
164
165 new_obj = (oop) _old_lab.allocate(new_obj_size);
166 new_obj_is_tenured = true;
167
168 if (new_obj == NULL) {
169 if (!_old_gen_is_full) {
170 // Do we allocate directly, or flush and refill?
171 if (new_obj_size > (OldPLABSize / 2)) {
172 // Allocate this object directly
173 new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
174 promotion_trace_event(new_obj, o, new_obj_size, age, true, NULL);
175 } else {
176 // Flush and fill
177 _old_lab.flush();
178
179 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
180 if(lab_base != NULL) {
181 #ifdef ASSERT
182 // Delay the initialization of the promotion lab (plab).
183 // This exposes uninitialized plabs to card table processing.
184 if (GCWorkerDelayMillis > 0) {
185 os::sleep(Thread::current(), GCWorkerDelayMillis, false);
186 }
187 #endif
188 _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
189 // Try the old lab allocation again.
190 new_obj = (oop) _old_lab.allocate(new_obj_size);
191 promotion_trace_event(new_obj, o, new_obj_size, age, true, &_old_lab);
192 }
193 }
194 }
195
196 // This is the promotion failed test, and code handling.
197 // The code belongs here for two reasons. It is slightly
198 // different than the code below, and cannot share the
199 // CAS testing code. Keeping the code here also minimizes
200 // the impact on the common case fast path code.
201
202 if (new_obj == NULL) {
203 _old_gen_is_full = true;
204 return oop_promotion_failed(o, test_mark);
205 }
206 }
207 }
208
209 assert(new_obj != NULL, "allocation should have succeeded");
210
211 // Copy obj
212 Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
213
214 // Now we have to CAS in the header.
215 if (o->cas_forward_to(new_obj, test_mark)) {
216 // We won any races, we "own" this object.
217 assert(new_obj == o->forwardee(), "Sanity");
218
219 // Increment age if obj still in new generation. Now that
220 // we're dealing with a markOop that cannot change, it is
221 // okay to use the non mt safe oop methods.
222 if (!new_obj_is_tenured) {
223 new_obj->incr_age();
224 assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
225 }
226
227 // Do the size comparison first with new_obj_size, which we
228 // already have. Hopefully, only a few objects are larger than
229 // _min_array_size_for_chunking, and most of them will be arrays.
230 // So, the is->objArray() test would be very infrequent.
231 if (new_obj_size > _min_array_size_for_chunking &&
232 new_obj->is_objArray() &&
233 PSChunkLargeArrays) {
234 // we'll chunk it
235 oop* const masked_o = mask_chunked_array_oop(o);
236 push_depth(masked_o);
237 TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
238 } else {
239 // we'll just push its contents
240 push_contents(new_obj);
241 }
242 } else {
243 // We lost, someone else "owns" this object
244 guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
245
246 // Try to deallocate the space. If it was directly allocated we cannot
247 // deallocate it, so we have to test. If the deallocation fails,
248 // overwrite with a filler object.
249 if (new_obj_is_tenured) {
250 if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
251 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
252 }
253 } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
254 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
255 }
256
257 // don't update this before the unallocation!
258 new_obj = o->forwardee();
259 }
260 } else {
261 assert(o->is_forwarded(), "Sanity");
262 new_obj = o->forwardee();
263 }
264
265 // This code must come after the CAS test, or it will print incorrect
266 // information.
267 log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
268 should_scavenge(&new_obj) ? "copying" : "tenuring",
269 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
270
271 return new_obj;
272 }
273
274 // Attempt to "claim" oop at p via CAS, push the new obj if successful
275 // This version tests the oop* to make sure it is within the heap before
276 // attempting marking.
277 template <class T, bool promote_immediately>
278 inline void PSPromotionManager::copy_and_push_safe_barrier(T* p) {
279 assert(should_scavenge(p, true), "revisiting object?");
280
281 oop o = oopDesc::load_decode_heap_oop_not_null(p);
282 oop new_obj = o->is_forwarded()
283 ? o->forwardee()
284 : copy_to_survivor_space<promote_immediately>(o);
285
286 // This code must come after the CAS test, or it will print incorrect
287 // information.
288 if (log_develop_is_enabled(Trace, gc, scavenge) && o->is_forwarded()) {
289 log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
290 "forwarding",
291 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
292 }
293
294 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
295
296 // We cannot mark without test, as some code passes us pointers
297 // that are outside the heap. These pointers are either from roots
298 // or from metadata.
299 if ((!PSScavenge::is_obj_in_young((HeapWord*)p)) &&
300 ParallelScavengeHeap::heap()->is_in_reserved(p)) {
301 if (PSScavenge::is_obj_in_young(new_obj)) {
302 PSScavenge::card_table()->inline_write_ref_field_gc(p, new_obj);
303 }
304 }
305 }
306
307 inline void PSPromotionManager::process_popped_location_depth(StarTask p) {
308 if (is_oop_masked(p)) {
309 assert(PSChunkLargeArrays, "invariant");
310 oop const old = unmask_chunked_array_oop(p);
311 process_array_chunk(old);
312 } else {
313 if (p.is_narrow()) {
314 assert(UseCompressedOops, "Error");
315 copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(p);
316 } else {
317 copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(p);
318 }
319 }
320 }
321
322 inline bool PSPromotionManager::steal_depth(int queue_num, int* seed, StarTask& t) {
323 return stack_array_depth()->steal(queue_num, seed, t);
324 }
325
326 #if TASKQUEUE_STATS
327 void PSPromotionManager::record_steal(StarTask& p) {
328 if (is_oop_masked(p)) {
329 ++_masked_steals;
330 }
331 }
332 #endif // TASKQUEUE_STATS
333
334 #endif // SHARE_VM_GC_PARALLEL_PSPROMOTIONMANAGER_INLINE_HPP