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.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
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.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(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,
68 size_t obj_size,
69 uint age, bool tenured,
70 const PSPromotionLAB* lab) {
71 // Skip if memory allocation failed
72 if (new_obj != NULL) {
73 const ParallelScavengeTracer* gc_tracer = PSScavenge::gc_tracer();
74
75 if (lab != NULL) {
76 // Promotion of object through newly allocated PLAB
77 if (gc_tracer->should_report_promotion_in_new_plab_event()) {
78 size_t obj_bytes = obj_size * HeapWordSize;
79 size_t lab_size = lab->capacity();
80 gc_tracer->report_promotion_in_new_plab_event(old_obj->klass(), obj_bytes,
81 age, tenured, lab_size);
82 }
83 } else {
84 // Promotion of object directly to heap
85 if (gc_tracer->should_report_promotion_outside_plab_event()) {
86 size_t obj_bytes = obj_size * HeapWordSize;
87 gc_tracer->report_promotion_outside_plab_event(old_obj->klass(), obj_bytes,
88 age, tenured);
89 }
90 }
91 }
92 }
93
94 inline void PSPromotionManager::push_contents(oop obj) {
95 obj->ps_push_contents(this);
96 }
97 //
98 // This method is pretty bulky. It would be nice to split it up
99 // into smaller submethods, but we need to be careful not to hurt
100 // performance.
101 //
102 template<bool promote_immediately>
103 oop PSPromotionManager::copy_to_survivor_space(oop o) {
104 assert(should_scavenge(&o), "Sanity");
105
106 oop new_obj = NULL;
107
108 // NOTE! We must be very careful with any methods that access the mark
109 // in o. There may be multiple threads racing on it, and it may be forwarded
110 // at any time. Do not use oop methods for accessing the mark!
111 markOop test_mark = o->mark();
112
113 // The same test as "o->is_forwarded()"
114 if (!test_mark->is_marked()) {
115 bool new_obj_is_tenured = false;
116 size_t new_obj_size = o->size();
117
118 // Find the objects age, MT safe.
119 uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
120 test_mark->displaced_mark_helper()->age() : test_mark->age();
121
122 if (!promote_immediately) {
123 // Try allocating obj in to-space (unless too old)
124 if (age < PSScavenge::tenuring_threshold()) {
125 new_obj = (oop) _young_lab.allocate(new_obj_size);
126 if (new_obj == NULL && !_young_gen_is_full) {
127 // Do we allocate directly, or flush and refill?
128 if (new_obj_size > (YoungPLABSize / 2)) {
129 // Allocate this object directly
130 new_obj = (oop)young_space()->cas_allocate(new_obj_size);
131 promotion_trace_event(new_obj, o, new_obj_size, age, false, NULL);
132 } else {
133 // Flush and fill
134 _young_lab.flush();
135
136 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
137 if (lab_base != NULL) {
138 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
139 // Try the young lab allocation again.
140 new_obj = (oop) _young_lab.allocate(new_obj_size);
141 promotion_trace_event(new_obj, o, new_obj_size, age, false, &_young_lab);
142 } else {
143 _young_gen_is_full = true;
144 }
145 }
146 }
147 }
148 }
149
150 // Otherwise try allocating obj tenured
151 if (new_obj == NULL) {
152 #ifndef PRODUCT
153 if (Universe::heap()->promotion_should_fail()) {
154 return oop_promotion_failed(o, test_mark);
155 }
156 #endif // #ifndef PRODUCT
157
158 new_obj = (oop) _old_lab.allocate(new_obj_size);
159 new_obj_is_tenured = true;
160
161 if (new_obj == NULL) {
162 if (!_old_gen_is_full) {
163 // Do we allocate directly, or flush and refill?
164 if (new_obj_size > (OldPLABSize / 2)) {
165 // Allocate this object directly
166 new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
167 promotion_trace_event(new_obj, o, new_obj_size, age, true, NULL);
168 } else {
169 // Flush and fill
170 _old_lab.flush();
171
172 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
173 if(lab_base != NULL) {
174 #ifdef ASSERT
175 // Delay the initialization of the promotion lab (plab).
176 // This exposes uninitialized plabs to card table processing.
177 if (GCWorkerDelayMillis > 0) {
178 os::sleep(Thread::current(), GCWorkerDelayMillis, false);
179 }
180 #endif
181 _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
182 // Try the old lab allocation again.
183 new_obj = (oop) _old_lab.allocate(new_obj_size);
184 promotion_trace_event(new_obj, o, new_obj_size, age, true, &_old_lab);
185 }
186 }
187 }
188
189 // This is the promotion failed test, and code handling.
190 // The code belongs here for two reasons. It is slightly
191 // different than the code below, and cannot share the
192 // CAS testing code. Keeping the code here also minimizes
193 // the impact on the common case fast path code.
194
195 if (new_obj == NULL) {
196 _old_gen_is_full = true;
197 return oop_promotion_failed(o, test_mark);
198 }
199 }
200 }
201
202 assert(new_obj != NULL, "allocation should have succeeded");
203
204 // Copy obj
205 Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
206
207 // Now we have to CAS in the header.
208 if (o->cas_forward_to(new_obj, test_mark)) {
209 // We won any races, we "own" this object.
210 assert(new_obj == o->forwardee(), "Sanity");
211
212 // Increment age if obj still in new generation. Now that
213 // we're dealing with a markOop that cannot change, it is
214 // okay to use the non mt safe oop methods.
215 if (!new_obj_is_tenured) {
216 new_obj->incr_age();
217 assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
218 }
219
220 // Do the size comparison first with new_obj_size, which we
221 // already have. Hopefully, only a few objects are larger than
222 // _min_array_size_for_chunking, and most of them will be arrays.
223 // So, the is->objArray() test would be very infrequent.
224 if (new_obj_size > _min_array_size_for_chunking &&
225 new_obj->is_objArray() &&
226 PSChunkLargeArrays) {
227 // we'll chunk it
228 oop* const masked_o = mask_chunked_array_oop(o);
229 push_depth(masked_o);
230 TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
231 } else {
232 // we'll just push its contents
233 push_contents(new_obj);
234 }
235 } else {
236 // We lost, someone else "owns" this object
237 guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
238
239 // Try to deallocate the space. If it was directly allocated we cannot
240 // deallocate it, so we have to test. If the deallocation fails,
241 // overwrite with a filler object.
242 if (new_obj_is_tenured) {
243 if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
244 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
245 }
246 } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
247 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
248 }
249
250 // don't update this before the unallocation!
251 new_obj = o->forwardee();
252 }
253 } else {
254 assert(o->is_forwarded(), "Sanity");
255 new_obj = o->forwardee();
256 }
257
258 #ifndef PRODUCT
259 // This code must come after the CAS test, or it will print incorrect
260 // information.
261 if (TraceScavenge) {
262 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
263 should_scavenge(&new_obj) ? "copying" : "tenuring",
264 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
265 }
266 #endif
267
268 return new_obj;
269 }
270
271 // Attempt to "claim" oop at p via CAS, push the new obj if successful
272 // This version tests the oop* to make sure it is within the heap before
273 // attempting marking.
274 template <class T, bool promote_immediately>
275 inline void PSPromotionManager::copy_and_push_safe_barrier(T* p) {
276 assert(should_scavenge(p, true), "revisiting object?");
277
278 oop o = oopDesc::load_decode_heap_oop_not_null(p);
279 oop new_obj = o->is_forwarded()
280 ? o->forwardee()
281 : copy_to_survivor_space<promote_immediately>(o);
282
283 #ifndef PRODUCT
284 // This code must come after the CAS test, or it will print incorrect
285 // information.
286 if (TraceScavenge && o->is_forwarded()) {
287 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
288 "forwarding",
289 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
290 }
291 #endif
292
293 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
294
295 // We cannot mark without test, as some code passes us pointers
296 // that are outside the heap. These pointers are either from roots
297 // or from metadata.
298 if ((!PSScavenge::is_obj_in_young((HeapWord*)p)) &&
299 Universe::heap()->is_in_reserved(p)) {
300 if (PSScavenge::is_obj_in_young(new_obj)) {
301 PSScavenge::card_table()->inline_write_ref_field_gc(p, new_obj);
302 }
303 }
304 }
305
306 inline void PSPromotionManager::process_popped_location_depth(StarTask p) {
307 if (is_oop_masked(p)) {
308 assert(PSChunkLargeArrays, "invariant");
309 oop const old = unmask_chunked_array_oop(p);
310 process_array_chunk(old);
311 } else {
312 if (p.is_narrow()) {
313 assert(UseCompressedOops, "Error");
314 copy_and_push_safe_barrier<narrowOop, /*promote_immediately=*/false>(p);
315 } else {
316 copy_and_push_safe_barrier<oop, /*promote_immediately=*/false>(p);
317 }
318 }
319 }
320
321 #if TASKQUEUE_STATS
322 void PSPromotionManager::record_steal(StarTask& p) {
323 if (is_oop_masked(p)) {
324 ++_masked_steals;
325 }
326 }
327 #endif // TASKQUEUE_STATS
328
329 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSPROMOTIONMANAGER_INLINE_HPP