1 /*
2 * Copyright (c) 2001, 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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20 * or visit www.oracle.com if you need additional information or have any
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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/concurrentMark.hpp"
29 #include "gc/g1/g1CollectedHeap.hpp"
30 #include "gc/g1/g1CollectorPolicy.hpp"
31 #include "gc/g1/g1CollectorState.hpp"
32 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
33 #include "gc/g1/heapRegionManager.inline.hpp"
34 #include "gc/g1/heapRegionSet.inline.hpp"
35 #include "gc/shared/taskqueue.hpp"
36 #include "runtime/orderAccess.inline.hpp"
37
38 G1EvacStats* G1CollectedHeap::alloc_buffer_stats(InCSetState dest) {
39 switch (dest.value()) {
40 case InCSetState::Young:
41 return &_survivor_evac_stats;
42 case InCSetState::Old:
43 return &_old_evac_stats;
44 default:
45 ShouldNotReachHere();
46 return NULL; // Keep some compilers happy
47 }
48 }
49
50 size_t G1CollectedHeap::desired_plab_sz(InCSetState dest) {
51 size_t gclab_word_size = alloc_buffer_stats(dest)->desired_plab_sz(G1CollectedHeap::heap()->workers()->active_workers());
52 // Prevent humongous PLAB sizes for two reasons:
53 // * PLABs are allocated using a similar paths as oops, but should
54 // never be in a humongous region
55 // * Allowing humongous PLABs needlessly churns the region free lists
56 return MIN2(_humongous_object_threshold_in_words, gclab_word_size);
57 }
58
59 // Inline functions for G1CollectedHeap
60
61 inline AllocationContextStats& G1CollectedHeap::allocation_context_stats() {
62 return _allocation_context_stats;
63 }
64
65 // Return the region with the given index. It assumes the index is valid.
66 inline HeapRegion* G1CollectedHeap::region_at(uint index) const { return _hrm.at(index); }
67
68 inline HeapRegion* G1CollectedHeap::next_region_in_humongous(HeapRegion* hr) const {
69 return _hrm.next_region_in_humongous(hr);
70 }
71
72 inline uint G1CollectedHeap::addr_to_region(HeapWord* addr) const {
73 assert(is_in_reserved(addr),
74 "Cannot calculate region index for address " PTR_FORMAT " that is outside of the heap [" PTR_FORMAT ", " PTR_FORMAT ")",
75 p2i(addr), p2i(reserved_region().start()), p2i(reserved_region().end()));
76 return (uint)(pointer_delta(addr, reserved_region().start(), sizeof(uint8_t)) >> HeapRegion::LogOfHRGrainBytes);
77 }
78
79 inline HeapWord* G1CollectedHeap::bottom_addr_for_region(uint index) const {
80 return _hrm.reserved().start() + index * HeapRegion::GrainWords;
81 }
82
83 template <class T>
84 inline HeapRegion* G1CollectedHeap::heap_region_containing(const T addr) const {
85 assert(addr != NULL, "invariant");
86 assert(is_in_g1_reserved((const void*) addr),
87 "Address " PTR_FORMAT " is outside of the heap ranging from [" PTR_FORMAT " to " PTR_FORMAT ")",
88 p2i((void*)addr), p2i(g1_reserved().start()), p2i(g1_reserved().end()));
89 return _hrm.addr_to_region((HeapWord*) addr);
90 }
91
92 inline void G1CollectedHeap::reset_gc_time_stamp() {
93 _gc_time_stamp = 0;
94 OrderAccess::fence();
95 // Clear the cached CSet starting regions and time stamps.
96 // Their validity is dependent on the GC timestamp.
97 clear_cset_start_regions();
98 }
99
100 inline void G1CollectedHeap::increment_gc_time_stamp() {
101 ++_gc_time_stamp;
102 OrderAccess::fence();
103 }
104
105 inline void G1CollectedHeap::old_set_add(HeapRegion* hr) {
106 _old_set.add(hr);
107 }
108
109 inline void G1CollectedHeap::old_set_remove(HeapRegion* hr) {
110 _old_set.remove(hr);
111 }
112
113 // It dirties the cards that cover the block so that so that the post
114 // write barrier never queues anything when updating objects on this
115 // block. It is assumed (and in fact we assert) that the block
116 // belongs to a young region.
117 inline void
118 G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {
119 assert_heap_not_locked();
120
121 // Assign the containing region to containing_hr so that we don't
122 // have to keep calling heap_region_containing() in the
123 // asserts below.
124 DEBUG_ONLY(HeapRegion* containing_hr = heap_region_containing(start);)
125 assert(word_size > 0, "pre-condition");
126 assert(containing_hr->is_in(start), "it should contain start");
127 assert(containing_hr->is_young(), "it should be young");
128 assert(!containing_hr->is_humongous(), "it should not be humongous");
129
130 HeapWord* end = start + word_size;
131 assert(containing_hr->is_in(end - 1), "it should also contain end - 1");
132
133 MemRegion mr(start, end);
134 g1_barrier_set()->g1_mark_as_young(mr);
135 }
136
137 inline RefToScanQueue* G1CollectedHeap::task_queue(uint i) const {
138 return _task_queues->queue(i);
139 }
140
141 inline bool G1CollectedHeap::isMarkedPrev(oop obj) const {
142 return _cm->prevMarkBitMap()->isMarked((HeapWord *)obj);
143 }
144
145 inline bool G1CollectedHeap::isMarkedNext(oop obj) const {
146 return _cm->nextMarkBitMap()->isMarked((HeapWord *)obj);
147 }
148
149 // This is a fast test on whether a reference points into the
150 // collection set or not. Assume that the reference
151 // points into the heap.
152 inline bool G1CollectedHeap::is_in_cset(oop obj) {
153 bool ret = _in_cset_fast_test.is_in_cset((HeapWord*)obj);
154 // let's make sure the result is consistent with what the slower
155 // test returns
156 assert( ret || !obj_in_cs(obj), "sanity");
157 assert(!ret || obj_in_cs(obj), "sanity");
158 return ret;
159 }
160
161 bool G1CollectedHeap::is_in_cset(const HeapRegion* hr) {
162 return _in_cset_fast_test.is_in_cset(hr);
163 }
164
165 bool G1CollectedHeap::is_in_cset_or_humongous(const oop obj) {
166 return _in_cset_fast_test.is_in_cset_or_humongous((HeapWord*)obj);
167 }
168
169 InCSetState G1CollectedHeap::in_cset_state(const oop obj) {
170 return _in_cset_fast_test.at((HeapWord*)obj);
171 }
172
173 void G1CollectedHeap::register_humongous_region_with_cset(uint index) {
174 _in_cset_fast_test.set_humongous(index);
175 }
176
177 #ifndef PRODUCT
178 // Support for G1EvacuationFailureALot
179
180 inline bool
181 G1CollectedHeap::evacuation_failure_alot_for_gc_type(bool gcs_are_young,
182 bool during_initial_mark,
183 bool during_marking) {
184 bool res = false;
185 if (during_marking) {
186 res |= G1EvacuationFailureALotDuringConcMark;
187 }
188 if (during_initial_mark) {
189 res |= G1EvacuationFailureALotDuringInitialMark;
190 }
191 if (gcs_are_young) {
192 res |= G1EvacuationFailureALotDuringYoungGC;
193 } else {
194 // GCs are mixed
195 res |= G1EvacuationFailureALotDuringMixedGC;
196 }
197 return res;
198 }
199
200 inline void
201 G1CollectedHeap::set_evacuation_failure_alot_for_current_gc() {
202 if (G1EvacuationFailureALot) {
203 // Note we can't assert that _evacuation_failure_alot_for_current_gc
204 // is clear here. It may have been set during a previous GC but that GC
205 // did not copy enough objects (i.e. G1EvacuationFailureALotCount) to
206 // trigger an evacuation failure and clear the flags and and counts.
207
208 // Check if we have gone over the interval.
209 const size_t gc_num = total_collections();
210 const size_t elapsed_gcs = gc_num - _evacuation_failure_alot_gc_number;
211
212 _evacuation_failure_alot_for_current_gc = (elapsed_gcs >= G1EvacuationFailureALotInterval);
213
214 // Now check if G1EvacuationFailureALot is enabled for the current GC type.
215 const bool gcs_are_young = collector_state()->gcs_are_young();
216 const bool during_im = collector_state()->during_initial_mark_pause();
217 const bool during_marking = collector_state()->mark_in_progress();
218
219 _evacuation_failure_alot_for_current_gc &=
220 evacuation_failure_alot_for_gc_type(gcs_are_young,
221 during_im,
222 during_marking);
223 }
224 }
225
226 inline bool G1CollectedHeap::evacuation_should_fail() {
227 if (!G1EvacuationFailureALot || !_evacuation_failure_alot_for_current_gc) {
228 return false;
229 }
230 // G1EvacuationFailureALot is in effect for current GC
231 // Access to _evacuation_failure_alot_count is not atomic;
232 // the value does not have to be exact.
233 if (++_evacuation_failure_alot_count < G1EvacuationFailureALotCount) {
234 return false;
235 }
236 _evacuation_failure_alot_count = 0;
237 return true;
238 }
239
240 inline void G1CollectedHeap::reset_evacuation_should_fail() {
241 if (G1EvacuationFailureALot) {
242 _evacuation_failure_alot_gc_number = total_collections();
243 _evacuation_failure_alot_count = 0;
244 _evacuation_failure_alot_for_current_gc = false;
245 }
246 }
247 #endif // #ifndef PRODUCT
248
249 inline bool G1CollectedHeap::is_in_young(const oop obj) {
250 if (obj == NULL) {
251 return false;
252 }
253 return heap_region_containing(obj)->is_young();
254 }
255
256 // We don't need barriers for initializing stores to objects
257 // in the young gen: for the SATB pre-barrier, there is no
258 // pre-value that needs to be remembered; for the remembered-set
259 // update logging post-barrier, we don't maintain remembered set
260 // information for young gen objects.
261 inline bool G1CollectedHeap::can_elide_initializing_store_barrier(oop new_obj) {
262 return is_in_young(new_obj);
263 }
264
265 inline bool G1CollectedHeap::is_obj_dead(const oop obj) const {
266 if (obj == NULL) {
267 return false;
268 }
269 return is_obj_dead(obj, heap_region_containing(obj));
270 }
271
272 inline bool G1CollectedHeap::is_obj_ill(const oop obj) const {
273 if (obj == NULL) {
274 return false;
275 }
276 return is_obj_ill(obj, heap_region_containing(obj));
277 }
278
279 inline void G1CollectedHeap::set_humongous_reclaim_candidate(uint region, bool value) {
280 assert(_hrm.at(region)->is_starts_humongous(), "Must start a humongous object");
281 _humongous_reclaim_candidates.set_candidate(region, value);
282 }
283
284 inline bool G1CollectedHeap::is_humongous_reclaim_candidate(uint region) {
285 assert(_hrm.at(region)->is_starts_humongous(), "Must start a humongous object");
286 return _humongous_reclaim_candidates.is_candidate(region);
287 }
288
289 inline void G1CollectedHeap::set_humongous_is_live(oop obj) {
290 uint region = addr_to_region((HeapWord*)obj);
291 // Clear the flag in the humongous_reclaim_candidates table. Also
292 // reset the entry in the _in_cset_fast_test table so that subsequent references
293 // to the same humongous object do not go into the slow path again.
294 // This is racy, as multiple threads may at the same time enter here, but this
295 // is benign.
296 // During collection we only ever clear the "candidate" flag, and only ever clear the
297 // entry in the in_cset_fast_table.
298 // We only ever evaluate the contents of these tables (in the VM thread) after
299 // having synchronized the worker threads with the VM thread, or in the same
300 // thread (i.e. within the VM thread).
301 if (is_humongous_reclaim_candidate(region)) {
302 set_humongous_reclaim_candidate(region, false);
303 _in_cset_fast_test.clear_humongous(region);
304 }
305 }
306
307 #endif // SHARE_VM_GC_G1_G1COLLECTEDHEAP_INLINE_HPP