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.
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/psOldGen.hpp"
30 #include "gc/parallel/psPromotionLAB.inline.hpp"
31 #include "gc/parallel/psPromotionManager.hpp"
32 #include "gc/parallel/psScavenge.hpp"
33 #include "gc/shared/taskqueue.inline.hpp"
34 #include "logging/log.hpp"
35 #include "oops/oop.inline.hpp"
36
37 inline PSPromotionManager* PSPromotionManager::manager_array(uint index) {
38 assert(_manager_array != NULL, "access of NULL manager_array");
39 assert(index <= ParallelGCThreads, "out of range manager_array access");
40 return &_manager_array[index];
41 }
42
43 template <class T>
44 inline void PSPromotionManager::push_depth(T* p) {
45 claimed_stack_depth()->push(p);
46 }
47
48 template <class T>
49 inline void PSPromotionManager::claim_or_forward_internal_depth(T* p) {
50 if (p != NULL) { // XXX: error if p != NULL here
51 oop o = oopDesc::load_decode_heap_oop_not_null(p);
52 if (o->is_forwarded()) {
53 o = o->forwardee();
54 // Card mark
55 if (PSScavenge::is_obj_in_young(o)) {
56 PSScavenge::card_table()->inline_write_ref_field_gc(p, o);
57 }
58 oopDesc::encode_store_heap_oop_not_null(p, o);
59 } else {
60 push_depth(p);
61 }
62 }
63 }
64
65 template <class T>
66 inline void PSPromotionManager::claim_or_forward_depth(T* p) {
67 assert(should_scavenge(p, true), "revisiting object?");
68 assert(ParallelScavengeHeap::heap()->is_in(p), "pointer outside heap");
69
70 claim_or_forward_internal_depth(p);
71 }
72
73 inline void PSPromotionManager::promotion_trace_event(oop new_obj, oop old_obj,
74 size_t obj_size,
75 uint age, bool tenured,
76 const PSPromotionLAB* lab) {
77 // Skip if memory allocation failed
78 if (new_obj != NULL) {
79 const ParallelScavengeTracer* gc_tracer = PSScavenge::gc_tracer();
80
81 if (lab != NULL) {
82 // Promotion of object through newly allocated PLAB
83 if (gc_tracer->should_report_promotion_in_new_plab_event()) {
84 size_t obj_bytes = obj_size * HeapWordSize;
85 size_t lab_size = lab->capacity();
86 gc_tracer->report_promotion_in_new_plab_event(old_obj->klass(), obj_bytes,
87 age, tenured, lab_size);
88 }
89 } else {
90 // Promotion of object directly to heap
91 if (gc_tracer->should_report_promotion_outside_plab_event()) {
92 size_t obj_bytes = obj_size * HeapWordSize;
93 gc_tracer->report_promotion_outside_plab_event(old_obj->klass(), obj_bytes,
94 age, tenured);
95 }
96 }
97 }
98 }
99
100 inline void PSPromotionManager::push_contents(oop obj) {
101 obj->ps_push_contents(this);
102 }
103 //
104 // This method is pretty bulky. It would be nice to split it up
105 // into smaller submethods, but we need to be careful not to hurt
106 // performance.
107 //
108 template<bool promote_immediately>
109 inline oop PSPromotionManager::copy_to_survivor_space(oop o) {
110 assert(should_scavenge(&o), "Sanity");
111
112 oop new_obj = NULL;
113
114 // NOTE! We must be very careful with any methods that access the mark
115 // in o. There may be multiple threads racing on it, and it may be forwarded
116 // at any time. Do not use oop methods for accessing the mark!
117 markOop test_mark = o->mark();
118
119 // The same test as "o->is_forwarded()"
120 if (!test_mark->is_marked()) {
121 bool new_obj_is_tenured = false;
122 size_t new_obj_size = o->size();
123
124 // Find the objects age, MT safe.
125 uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
126 test_mark->displaced_mark_helper()->age() : test_mark->age();
127
128 if (!promote_immediately) {
129 // Try allocating obj in to-space (unless too old)
130 if (age < PSScavenge::tenuring_threshold()) {
131 new_obj = (oop) _young_lab.allocate(new_obj_size);
132 if (new_obj == NULL && !_young_gen_is_full) {
133 // Do we allocate directly, or flush and refill?
134 if (new_obj_size > (YoungPLABSize / 2)) {
135 // Allocate this object directly
136 new_obj = (oop)young_space()->cas_allocate(new_obj_size);
137 promotion_trace_event(new_obj, o, new_obj_size, age, false, NULL);
138 } else {
139 // Flush and fill
140 _young_lab.flush();
141
142 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
143 if (lab_base != NULL) {
144 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
145 // Try the young lab allocation again.
146 new_obj = (oop) _young_lab.allocate(new_obj_size);
147 promotion_trace_event(new_obj, o, new_obj_size, age, false, &_young_lab);
148 } else {
149 _young_gen_is_full = true;
150 }
151 }
152 }
153 }
154 }
155
156 // Otherwise try allocating obj tenured
157 if (new_obj == NULL) {
158 #ifndef PRODUCT
159 if (ParallelScavengeHeap::heap()->promotion_should_fail()) {
160 return oop_promotion_failed(o, test_mark);
161 }
162 #endif // #ifndef PRODUCT
163
164 new_obj = (oop) _old_lab.allocate(new_obj_size);
165 new_obj_is_tenured = true;
166
167 if (new_obj == NULL) {
168 if (!_old_gen_is_full) {
169 // Do we allocate directly, or flush and refill?
170 if (new_obj_size > (OldPLABSize / 2)) {
171 // Allocate this object directly
172 new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
173 promotion_trace_event(new_obj, o, new_obj_size, age, true, NULL);
174 } else {
175 // Flush and fill
176 _old_lab.flush();
177
178 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
179 if(lab_base != NULL) {
180 #ifdef ASSERT
181 // Delay the initialization of the promotion lab (plab).
182 // This exposes uninitialized plabs to card table processing.
183 if (GCWorkerDelayMillis > 0) {
184 os::sleep(Thread::current(), GCWorkerDelayMillis, false);
185 }
186 #endif
187 _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
188 // Try the old lab allocation again.
189 new_obj = (oop) _old_lab.allocate(new_obj_size);
190 promotion_trace_event(new_obj, o, new_obj_size, age, true, &_old_lab);
191 }
192 }
193 }
194
195 // This is the promotion failed test, and code handling.
196 // The code belongs here for two reasons. It is slightly
197 // different than the code below, and cannot share the
198 // CAS testing code. Keeping the code here also minimizes
199 // the impact on the common case fast path code.
200
201 if (new_obj == NULL) {
202 _old_gen_is_full = true;
203 return oop_promotion_failed(o, test_mark);
204 }
205 }
206 }
207
208 assert(new_obj != NULL, "allocation should have succeeded");
209
210 // Copy obj
211 Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
212
213 // Now we have to CAS in the header.
214 if (o->cas_forward_to(new_obj, test_mark, memory_order_relaxed)) {
215 // We won any races, we "own" this object.
216 assert(new_obj == o->forwardee(), "Sanity");
217
218 // Increment age if obj still in new generation. Now that
219 // we're dealing with a markOop that cannot change, it is
220 // okay to use the non mt safe oop methods.
221 if (!new_obj_is_tenured) {
222 new_obj->incr_age();
223 assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
224 }
225
226 // Do the size comparison first with new_obj_size, which we
227 // already have. Hopefully, only a few objects are larger than
228 // _min_array_size_for_chunking, and most of them will be arrays.
229 // So, the is->objArray() test would be very infrequent.
230 if (new_obj_size > _min_array_size_for_chunking &&
231 new_obj->is_objArray() &&
232 PSChunkLargeArrays) {
233 // we'll chunk it
234 oop* const masked_o = mask_chunked_array_oop(o);
235 push_depth(masked_o);
236 TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
237 } else {
238 // we'll just push its contents
239 push_contents(new_obj);
240 }
241
242 // This code must come after the CAS test, or it will print incorrect
243 // information.
244 log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
245 should_scavenge(&new_obj) ? "copying" : "tenuring",
246 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj),
247 new_obj->size());
248 } else {
249 // We lost, someone else "owns" this object
250 guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
251
252 // Try to deallocate the space. If it was directly allocated we cannot
253 // deallocate it, so we have to test. If the deallocation fails,
254 // overwrite with a filler object.
255 if (new_obj_is_tenured) {
256 if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
257 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
258 }
259 } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
260 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
261 }
262
263 // don't update this before the unallocation!
264 new_obj = o->forwardee();
265
266 // fields in new_obj may not be synchronized.
267 log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT "}",
268 should_scavenge(&new_obj) ? "copying" : "tenuring",
269 o->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj));
270 }
271 } else {
272 assert(o->is_forwarded(), "Sanity");
273 new_obj = o->forwardee();
274 // fields in new_obj may not be synchronized.
275 log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT "}",
276 should_scavenge(&new_obj) ? "copying" : "tenuring",
277 o->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj));
278 }
279
280 return new_obj;
281 }
282
283 // Attempt to "claim" oop at p via CAS, push the new obj if successful
284 // This version tests the oop* to make sure it is within the heap before
285 // attempting marking.
286 template <class T, bool promote_immediately>
287 inline void PSPromotionManager::copy_and_push_safe_barrier(T* p) {
288 assert(should_scavenge(p, true), "revisiting object?");
289
290 oop o = oopDesc::load_decode_heap_oop_not_null(p);
291 oop new_obj;
292
293 if (o->is_forwarded()) {
294 new_obj = o->forwardee();
295 // fields in new_obj may not be synchronized.
296 if (log_develop_is_enabled(Trace, gc, scavenge) && o->is_forwarded()) {
297 log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT "}",
298 "forwarding",
299 o->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj));
300 }
301 } else {
302 new_obj = copy_to_survivor_space<promote_immediately>(o);
303 // This code must come after the CAS test, or it will print incorrect
304 // information.
305 if (log_develop_is_enabled(Trace, gc, scavenge) && o->is_forwarded()) {
306 log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
307 "forwarding",
308 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj),
309 new_obj->size());
310 }
311 }
312
313 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
314
315 // We cannot mark without test, as some code passes us pointers
316 // that are outside the heap. These pointers are either from roots
317 // or from metadata.
318 if ((!PSScavenge::is_obj_in_young((HeapWord*)p)) &&
319 ParallelScavengeHeap::heap()->is_in_reserved(p)) {
320 if (PSScavenge::is_obj_in_young(new_obj)) {
321 PSScavenge::card_table()->inline_write_ref_field_gc(p, new_obj);
322 }
323 }
324 }
325
326 inline void PSPromotionManager::process_popped_location_depth(StarTask p) {
327 if (is_oop_masked(p)) {
328 assert(PSChunkLargeArrays, "invariant");
329 oop const old = unmask_chunked_array_oop(p);
330 process_array_chunk(old);
331 } else {
332 if (p.is_narrow()) {
333 assert(UseCompressedOops, "Error");
334 copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(p);
335 } else {
336 copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(p);
337 }
338 }
339 }
340
341 inline bool PSPromotionManager::steal_depth(int queue_num, int* seed, StarTask& t) {
342 return stack_array_depth()->steal(queue_num, seed, t);
343 }
344
345 #if TASKQUEUE_STATS
346 void PSPromotionManager::record_steal(StarTask& p) {
347 if (is_oop_masked(p)) {
348 ++_masked_steals;
349 }
350 }
351 #endif // TASKQUEUE_STATS
352
353 #endif // SHARE_VM_GC_PARALLEL_PSPROMOTIONMANAGER_INLINE_HPP