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.
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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_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/access.inline.hpp"
37 #include "oops/oop.inline.hpp"
38
39 inline PSPromotionManager* PSPromotionManager::manager_array(uint index) {
40 assert(_manager_array != NULL, "access of NULL manager_array");
41 assert(index <= ParallelGCThreads, "out of range manager_array access");
42 return &_manager_array[index];
43 }
44
45 template <class T>
46 inline void PSPromotionManager::push_depth(T* p) {
47 claimed_stack_depth()->push(p);
48 }
49
50 template <class T>
51 inline void PSPromotionManager::claim_or_forward_internal_depth(T* p) {
52 if (p != NULL) { // XXX: error if p != NULL here
53 oop o = RawAccess<IS_NOT_NULL>::oop_load(p);
54 if (o->is_forwarded()) {
55 o = o->forwardee();
56 // Card mark
57 if (PSScavenge::is_obj_in_young(o)) {
58 PSScavenge::card_table()->inline_write_ref_field_gc(p, o);
59 }
60 RawAccess<IS_NOT_NULL>::oop_store(p, o);
61 } else {
62 push_depth(p);
63 }
64 }
65 }
66
67 template <class T>
68 inline void PSPromotionManager::claim_or_forward_depth(T* p) {
69 assert(should_scavenge(p, true), "revisiting object?");
70 assert(ParallelScavengeHeap::heap()->is_in(p), "pointer outside heap");
71
72 claim_or_forward_internal_depth(p);
73 }
74
75 inline void PSPromotionManager::promotion_trace_event(oop new_obj, oop old_obj,
76 size_t obj_size,
77 uint age, bool tenured,
78 const PSPromotionLAB* lab) {
79 // Skip if memory allocation failed
80 if (new_obj != NULL) {
81 const ParallelScavengeTracer* gc_tracer = PSScavenge::gc_tracer();
82
83 if (lab != NULL) {
84 // Promotion of object through newly allocated PLAB
85 if (gc_tracer->should_report_promotion_in_new_plab_event()) {
86 size_t obj_bytes = obj_size * HeapWordSize;
87 size_t lab_size = lab->capacity();
88 gc_tracer->report_promotion_in_new_plab_event(old_obj->klass(), obj_bytes,
89 age, tenured, lab_size);
90 }
91 } else {
92 // Promotion of object directly to heap
93 if (gc_tracer->should_report_promotion_outside_plab_event()) {
94 size_t obj_bytes = obj_size * HeapWordSize;
95 gc_tracer->report_promotion_outside_plab_event(old_obj->klass(), obj_bytes,
96 age, tenured);
97 }
98 }
99 }
100 }
101
102 inline void PSPromotionManager::push_contents(oop obj) {
103 obj->ps_push_contents(this);
104 }
105 //
106 // This method is pretty bulky. It would be nice to split it up
107 // into smaller submethods, but we need to be careful not to hurt
108 // performance.
109 //
110 template<bool promote_immediately>
111 inline oop PSPromotionManager::copy_to_survivor_space(oop o) {
112 assert(should_scavenge(&o), "Sanity");
113
114 oop new_obj = NULL;
115
116 // NOTE! We must be very careful with any methods that access the mark
117 // in o. There may be multiple threads racing on it, and it may be forwarded
118 // at any time. Do not use oop methods for accessing the mark!
119 markOop test_mark = o->mark_raw();
120
121 // The same test as "o->is_forwarded()"
122 if (!test_mark->is_marked()) {
123 bool new_obj_is_tenured = false;
124 size_t new_obj_size = o->size();
125
126 // Find the objects age, MT safe.
127 uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
128 test_mark->displaced_mark_helper()->age() : test_mark->age();
129
130 if (!promote_immediately) {
131 // Try allocating obj in to-space (unless too old)
132 if (age < PSScavenge::tenuring_threshold()) {
133 new_obj = (oop) _young_lab.allocate(new_obj_size);
134 if (new_obj == NULL && !_young_gen_is_full) {
135 // Do we allocate directly, or flush and refill?
136 if (new_obj_size > (YoungPLABSize / 2)) {
137 // Allocate this object directly
138 new_obj = (oop)young_space()->cas_allocate(new_obj_size);
139 promotion_trace_event(new_obj, o, new_obj_size, age, false, NULL);
140 } else {
141 // Flush and fill
142 _young_lab.flush();
143
144 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
145 if (lab_base != NULL) {
146 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
147 // Try the young lab allocation again.
148 new_obj = (oop) _young_lab.allocate(new_obj_size);
149 promotion_trace_event(new_obj, o, new_obj_size, age, false, &_young_lab);
150 } else {
151 _young_gen_is_full = true;
152 }
153 }
154 }
155 }
156 }
157
158 // Otherwise try allocating obj tenured
159 if (new_obj == NULL) {
160 #ifndef PRODUCT
161 if (ParallelScavengeHeap::heap()->promotion_should_fail()) {
162 return oop_promotion_failed(o, test_mark);
163 }
164 #endif // #ifndef PRODUCT
165
166 new_obj = (oop) _old_lab.allocate(new_obj_size);
167 new_obj_is_tenured = true;
168
169 if (new_obj == NULL) {
170 if (!_old_gen_is_full) {
171 // Do we allocate directly, or flush and refill?
172 if (new_obj_size > (OldPLABSize / 2)) {
173 // Allocate this object directly
174 new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
175 promotion_trace_event(new_obj, o, new_obj_size, age, true, NULL);
176 } else {
177 // Flush and fill
178 _old_lab.flush();
179
180 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
181 if(lab_base != NULL) {
182 #ifdef ASSERT
183 // Delay the initialization of the promotion lab (plab).
184 // This exposes uninitialized plabs to card table processing.
185 if (GCWorkerDelayMillis > 0) {
186 os::sleep(Thread::current(), GCWorkerDelayMillis, false);
187 }
188 #endif
189 _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
190 // Try the old lab allocation again.
191 new_obj = (oop) _old_lab.allocate(new_obj_size);
192 promotion_trace_event(new_obj, o, new_obj_size, age, true, &_old_lab);
193 }
194 }
195 }
196
197 // This is the promotion failed test, and code handling.
198 // The code belongs here for two reasons. It is slightly
199 // different than the code below, and cannot share the
200 // CAS testing code. Keeping the code here also minimizes
201 // the impact on the common case fast path code.
202
203 if (new_obj == NULL) {
204 _old_gen_is_full = true;
205 return oop_promotion_failed(o, test_mark);
206 }
207 }
208 }
209
210 assert(new_obj != NULL, "allocation should have succeeded");
211
212 // Copy obj
213 Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
214
215 // Now we have to CAS in the header.
216 // Make copy visible to threads reading the forwardee.
217 if (o->cas_forward_to(new_obj, test_mark, memory_order_release)) {
218 // We won any races, we "own" this object.
219 assert(new_obj == o->forwardee(), "Sanity");
220
221 // Increment age if obj still in new generation. Now that
222 // we're dealing with a markOop that cannot change, it is
223 // okay to use the non mt safe oop methods.
224 if (!new_obj_is_tenured) {
225 new_obj->incr_age();
226 assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
227 }
228
229 // Do the size comparison first with new_obj_size, which we
230 // already have. Hopefully, only a few objects are larger than
231 // _min_array_size_for_chunking, and most of them will be arrays.
232 // So, the is->objArray() test would be very infrequent.
233 if (new_obj_size > _min_array_size_for_chunking &&
234 new_obj->is_objArray() &&
235 PSChunkLargeArrays) {
236 // we'll chunk it
237 oop* const masked_o = mask_chunked_array_oop(o);
238 push_depth(masked_o);
239 TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
240 } else {
241 // we'll just push its contents
242 push_contents(new_obj);
243 }
244 } else {
245 // We lost, someone else "owns" this object
246 guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
247
248 // Try to deallocate the space. If it was directly allocated we cannot
249 // deallocate it, so we have to test. If the deallocation fails,
250 // overwrite with a filler object.
251 if (new_obj_is_tenured) {
252 if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
253 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
254 }
255 } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
256 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
257 }
258
259 // don't update this before the unallocation!
260 // Using acquire though consume would be accurate for accessing new_obj.
261 new_obj = o->forwardee_acquire();
262 }
263 } else {
264 assert(o->is_forwarded(), "Sanity");
265 new_obj = o->forwardee_acquire();
266 }
267
268 // This code must come after the CAS test, or it will print incorrect
269 // information.
270 log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
271 should_scavenge(&new_obj) ? "copying" : "tenuring",
272 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
273
274 return new_obj;
275 }
276
277 // Attempt to "claim" oop at p via CAS, push the new obj if successful
278 // This version tests the oop* to make sure it is within the heap before
279 // attempting marking.
280 template <class T, bool promote_immediately>
281 inline void PSPromotionManager::copy_and_push_safe_barrier(T* p) {
282 assert(should_scavenge(p, true), "revisiting object?");
283
284 oop o = RawAccess<IS_NOT_NULL>::oop_load(p);
285 oop new_obj = o->is_forwarded()
286 ? o->forwardee()
287 : copy_to_survivor_space<promote_immediately>(o);
288
289 // This code must come after the CAS test, or it will print incorrect
290 // information.
291 if (log_develop_is_enabled(Trace, gc, scavenge) && o->is_forwarded()) {
292 log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
293 "forwarding",
294 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
295 }
296
297 RawAccess<IS_NOT_NULL>::oop_store(p, new_obj);
298
299 // We cannot mark without test, as some code passes us pointers
300 // that are outside the heap. These pointers are either from roots
301 // or from metadata.
302 if ((!PSScavenge::is_obj_in_young((HeapWord*)p)) &&
303 ParallelScavengeHeap::heap()->is_in_reserved(p)) {
304 if (PSScavenge::is_obj_in_young(new_obj)) {
305 PSScavenge::card_table()->inline_write_ref_field_gc(p, new_obj);
306 }
307 }
308 }
309
310 inline void PSPromotionManager::process_popped_location_depth(StarTask p) {
311 if (is_oop_masked(p)) {
312 assert(PSChunkLargeArrays, "invariant");
313 oop const old = unmask_chunked_array_oop(p);
314 process_array_chunk(old);
315 } else {
316 if (p.is_narrow()) {
317 assert(UseCompressedOops, "Error");
318 copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(p);
319 } else {
320 copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(p);
321 }
322 }
323 }
324
325 inline bool PSPromotionManager::steal_depth(int queue_num, StarTask& t) {
326 return stack_array_depth()->steal(queue_num, t);
327 }
328
329 #if TASKQUEUE_STATS
330 void PSPromotionManager::record_steal(StarTask& p) {
331 if (is_oop_masked(p)) {
332 ++_masked_steals;
333 }
334 }
335 #endif // TASKQUEUE_STATS
336
337 #endif // SHARE_VM_GC_PARALLEL_PSPROMOTIONMANAGER_INLINE_HPP