1 /*
2 * Copyright (c) 2001, 2017, 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
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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_G1_G1COLLECTEDHEAP_INLINE_HPP
26 #define SHARE_VM_GC_G1_G1COLLECTEDHEAP_INLINE_HPP
27
28 #include "gc/g1/g1CollectedHeap.hpp"
29 #include "gc/g1/g1CollectorState.hpp"
30 #include "gc/g1/g1ConcurrentMark.inline.hpp"
31 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
32 #include "gc/g1/heapRegionManager.inline.hpp"
33 #include "gc/g1/heapRegionSet.inline.hpp"
34 #include "gc/shared/taskqueue.hpp"
35 #include "runtime/orderAccess.inline.hpp"
36
37 G1EvacStats* G1CollectedHeap::alloc_buffer_stats(InCSetState dest) {
38 switch (dest.value()) {
39 case InCSetState::Young:
40 return &_survivor_evac_stats;
41 case InCSetState::Old:
42 return &_old_evac_stats;
43 default:
44 ShouldNotReachHere();
45 return NULL; // Keep some compilers happy
46 }
47 }
48
49 size_t G1CollectedHeap::desired_plab_sz(InCSetState dest) {
50 size_t gclab_word_size = alloc_buffer_stats(dest)->desired_plab_sz(G1CollectedHeap::heap()->workers()->active_workers());
51 // Prevent humongous PLAB sizes for two reasons:
52 // * PLABs are allocated using a similar paths as oops, but should
53 // never be in a humongous region
54 // * Allowing humongous PLABs needlessly churns the region free lists
55 return MIN2(_humongous_object_threshold_in_words, gclab_word_size);
56 }
57
58 // Inline functions for G1CollectedHeap
59
60 inline AllocationContextStats& G1CollectedHeap::allocation_context_stats() {
61 return _allocation_context_stats;
62 }
63
64 // Return the region with the given index. It assumes the index is valid.
65 inline HeapRegion* G1CollectedHeap::region_at(uint index) const { return _hrm.at(index); }
66
67 inline HeapRegion* G1CollectedHeap::next_region_in_humongous(HeapRegion* hr) const {
68 return _hrm.next_region_in_humongous(hr);
69 }
70
71 inline uint G1CollectedHeap::addr_to_region(HeapWord* addr) const {
72 assert(is_in_reserved(addr),
73 "Cannot calculate region index for address " PTR_FORMAT " that is outside of the heap [" PTR_FORMAT ", " PTR_FORMAT ")",
74 p2i(addr), p2i(reserved_region().start()), p2i(reserved_region().end()));
75 return (uint)(pointer_delta(addr, reserved_region().start(), sizeof(uint8_t)) >> HeapRegion::LogOfHRGrainBytes);
76 }
77
78 inline HeapWord* G1CollectedHeap::bottom_addr_for_region(uint index) const {
79 return _hrm.reserved().start() + index * HeapRegion::GrainWords;
80 }
81
82 template <class T>
83 inline HeapRegion* G1CollectedHeap::heap_region_containing(const T addr) const {
84 assert(addr != NULL, "invariant");
85 assert(is_in_g1_reserved((const void*) addr),
86 "Address " PTR_FORMAT " is outside of the heap ranging from [" PTR_FORMAT " to " PTR_FORMAT ")",
87 p2i((void*)addr), p2i(g1_reserved().start()), p2i(g1_reserved().end()));
88 return _hrm.addr_to_region((HeapWord*) addr);
89 }
90
91 inline void G1CollectedHeap::reset_gc_time_stamp() {
92 assert_at_safepoint(true);
93 _gc_time_stamp = 0;
94 }
95
96 inline void G1CollectedHeap::increment_gc_time_stamp() {
97 assert_at_safepoint(true);
98 ++_gc_time_stamp;
99 }
100
101 inline void G1CollectedHeap::old_set_add(HeapRegion* hr) {
102 _old_set.add(hr);
103 }
104
105 inline void G1CollectedHeap::old_set_remove(HeapRegion* hr) {
106 _old_set.remove(hr);
107 }
108
109 // It dirties the cards that cover the block so that the post
110 // write barrier never queues anything when updating objects on this
111 // block. It is assumed (and in fact we assert) that the block
112 // belongs to a young region.
113 inline void
114 G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {
115 assert_heap_not_locked();
116
117 // Assign the containing region to containing_hr so that we don't
118 // have to keep calling heap_region_containing() in the
119 // asserts below.
120 DEBUG_ONLY(HeapRegion* containing_hr = heap_region_containing(start);)
121 assert(word_size > 0, "pre-condition");
122 assert(containing_hr->is_in(start), "it should contain start");
123 assert(containing_hr->is_young(), "it should be young");
124 assert(!containing_hr->is_humongous(), "it should not be humongous");
125
126 HeapWord* end = start + word_size;
127 assert(containing_hr->is_in(end - 1), "it should also contain end - 1");
128
129 MemRegion mr(start, end);
130 g1_barrier_set()->g1_mark_as_young(mr);
131 }
132
133 inline RefToScanQueue* G1CollectedHeap::task_queue(uint i) const {
134 return _task_queues->queue(i);
135 }
136
137 inline bool G1CollectedHeap::isMarkedNext(oop obj) const {
138 return _cm->next_mark_bitmap()->is_marked((HeapWord*)obj);
139 }
140
141 inline bool G1CollectedHeap::is_in_cset(oop obj) {
142 return is_in_cset((HeapWord*)obj);
143 }
144
145 inline bool G1CollectedHeap::is_in_cset(HeapWord* addr) {
146 return _in_cset_fast_test.is_in_cset(addr);
147 }
148
149 bool G1CollectedHeap::is_in_cset(const HeapRegion* hr) {
150 return _in_cset_fast_test.is_in_cset(hr);
151 }
152
153 bool G1CollectedHeap::is_in_cset_or_humongous(const oop obj) {
154 return _in_cset_fast_test.is_in_cset_or_humongous((HeapWord*)obj);
155 }
156
157 InCSetState G1CollectedHeap::in_cset_state(const oop obj) {
158 return _in_cset_fast_test.at((HeapWord*)obj);
159 }
160
161 void G1CollectedHeap::register_humongous_region_with_cset(uint index) {
162 _in_cset_fast_test.set_humongous(index);
163 }
164
165 #ifndef PRODUCT
166 // Support for G1EvacuationFailureALot
167
168 inline bool
169 G1CollectedHeap::evacuation_failure_alot_for_gc_type(bool gcs_are_young,
170 bool during_initial_mark,
171 bool during_marking) {
172 bool res = false;
173 if (during_marking) {
174 res |= G1EvacuationFailureALotDuringConcMark;
175 }
176 if (during_initial_mark) {
177 res |= G1EvacuationFailureALotDuringInitialMark;
178 }
179 if (gcs_are_young) {
180 res |= G1EvacuationFailureALotDuringYoungGC;
181 } else {
182 // GCs are mixed
183 res |= G1EvacuationFailureALotDuringMixedGC;
184 }
185 return res;
186 }
187
188 inline void
189 G1CollectedHeap::set_evacuation_failure_alot_for_current_gc() {
190 if (G1EvacuationFailureALot) {
191 // Note we can't assert that _evacuation_failure_alot_for_current_gc
192 // is clear here. It may have been set during a previous GC but that GC
193 // did not copy enough objects (i.e. G1EvacuationFailureALotCount) to
194 // trigger an evacuation failure and clear the flags and and counts.
195
196 // Check if we have gone over the interval.
197 const size_t gc_num = total_collections();
198 const size_t elapsed_gcs = gc_num - _evacuation_failure_alot_gc_number;
199
200 _evacuation_failure_alot_for_current_gc = (elapsed_gcs >= G1EvacuationFailureALotInterval);
201
202 // Now check if G1EvacuationFailureALot is enabled for the current GC type.
203 const bool gcs_are_young = collector_state()->gcs_are_young();
204 const bool during_im = collector_state()->during_initial_mark_pause();
205 const bool during_marking = collector_state()->mark_in_progress();
206
207 _evacuation_failure_alot_for_current_gc &=
208 evacuation_failure_alot_for_gc_type(gcs_are_young,
209 during_im,
210 during_marking);
211 }
212 }
213
214 inline bool G1CollectedHeap::evacuation_should_fail() {
215 if (!G1EvacuationFailureALot || !_evacuation_failure_alot_for_current_gc) {
216 return false;
217 }
218 // G1EvacuationFailureALot is in effect for current GC
219 // Access to _evacuation_failure_alot_count is not atomic;
220 // the value does not have to be exact.
221 if (++_evacuation_failure_alot_count < G1EvacuationFailureALotCount) {
222 return false;
223 }
224 _evacuation_failure_alot_count = 0;
225 return true;
226 }
227
228 inline void G1CollectedHeap::reset_evacuation_should_fail() {
229 if (G1EvacuationFailureALot) {
230 _evacuation_failure_alot_gc_number = total_collections();
231 _evacuation_failure_alot_count = 0;
232 _evacuation_failure_alot_for_current_gc = false;
233 }
234 }
235 #endif // #ifndef PRODUCT
236
237 inline bool G1CollectedHeap::is_in_young(const oop obj) {
238 if (obj == NULL) {
239 return false;
240 }
241 return heap_region_containing(obj)->is_young();
242 }
243
244 // We don't need barriers for initializing stores to objects
245 // in the young gen: for the SATB pre-barrier, there is no
246 // pre-value that needs to be remembered; for the remembered-set
247 // update logging post-barrier, we don't maintain remembered set
248 // information for young gen objects.
249 inline bool G1CollectedHeap::can_elide_initializing_store_barrier(oop new_obj) {
250 return is_in_young(new_obj);
251 }
252
253 inline bool G1CollectedHeap::is_obj_dead(const oop obj) const {
254 if (obj == NULL) {
255 return false;
256 }
257 return is_obj_dead(obj, heap_region_containing(obj));
258 }
259
260 inline bool G1CollectedHeap::is_obj_ill(const oop obj) const {
261 if (obj == NULL) {
262 return false;
263 }
264 return is_obj_ill(obj, heap_region_containing(obj));
265 }
266
267 inline bool G1CollectedHeap::is_obj_dead_full(const oop obj, const HeapRegion* hr) const {
268 return !isMarkedNext(obj) && !hr->is_archive();
269 }
270
271 inline bool G1CollectedHeap::is_obj_dead_full(const oop obj) const {
272 return is_obj_dead_full(obj, heap_region_containing(obj));
273 }
274
275 inline void G1CollectedHeap::set_humongous_reclaim_candidate(uint region, bool value) {
276 assert(_hrm.at(region)->is_starts_humongous(), "Must start a humongous object");
277 _humongous_reclaim_candidates.set_candidate(region, value);
278 }
279
280 inline bool G1CollectedHeap::is_humongous_reclaim_candidate(uint region) {
281 assert(_hrm.at(region)->is_starts_humongous(), "Must start a humongous object");
282 return _humongous_reclaim_candidates.is_candidate(region);
283 }
284
285 inline void G1CollectedHeap::set_humongous_is_live(oop obj) {
286 uint region = addr_to_region((HeapWord*)obj);
287 // Clear the flag in the humongous_reclaim_candidates table. Also
288 // reset the entry in the _in_cset_fast_test table so that subsequent references
289 // to the same humongous object do not go into the slow path again.
290 // This is racy, as multiple threads may at the same time enter here, but this
291 // is benign.
292 // During collection we only ever clear the "candidate" flag, and only ever clear the
293 // entry in the in_cset_fast_table.
294 // We only ever evaluate the contents of these tables (in the VM thread) after
295 // having synchronized the worker threads with the VM thread, or in the same
296 // thread (i.e. within the VM thread).
297 if (is_humongous_reclaim_candidate(region)) {
298 set_humongous_reclaim_candidate(region, false);
299 _in_cset_fast_test.clear_humongous(region);
300 }
301 }
302
303 #endif // SHARE_VM_GC_G1_G1COLLECTEDHEAP_INLINE_HPP