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
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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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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP
27
28 #include "gc_implementation/g1/concurrentMark.hpp"
29 #include "gc_implementation/g1/g1CollectedHeap.hpp"
30 #include "gc_implementation/g1/g1AllocRegion.inline.hpp"
31 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
32 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
33 #include "gc_implementation/g1/heapRegionManager.inline.hpp"
34 #include "gc_implementation/g1/heapRegionSet.inline.hpp"
35 #include "runtime/orderAccess.inline.hpp"
36 #include "utilities/taskqueue.hpp"
37
38 PLABStats* G1CollectedHeap::alloc_buffer_stats(InCSetState dest) {
39 switch (dest.value()) {
40 case InCSetState::Young:
41 return &_survivor_plab_stats;
42 case InCSetState::Old:
43 return &_old_plab_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();
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 HeapWord* G1CollectedHeap::par_allocate_during_gc(InCSetState dest,
60 size_t word_size,
61 AllocationContext_t context) {
62 switch (dest.value()) {
63 case InCSetState::Young:
64 return survivor_attempt_allocation(word_size, context);
65 case InCSetState::Old:
66 return old_attempt_allocation(word_size, context);
67 default:
68 ShouldNotReachHere();
69 return NULL; // Keep some compilers happy
70 }
71 }
72
73 // Inline functions for G1CollectedHeap
74
75 inline AllocationContextStats& G1CollectedHeap::allocation_context_stats() {
76 return _allocation_context_stats;
77 }
78
79 // Return the region with the given index. It assumes the index is valid.
80 inline HeapRegion* G1CollectedHeap::region_at(uint index) const { return _hrm.at(index); }
81
82 inline uint G1CollectedHeap::addr_to_region(HeapWord* addr) const {
83 assert(is_in_reserved(addr),
84 err_msg("Cannot calculate region index for address "PTR_FORMAT" that is outside of the heap ["PTR_FORMAT", "PTR_FORMAT")",
85 p2i(addr), p2i(reserved_region().start()), p2i(reserved_region().end())));
86 return (uint)(pointer_delta(addr, reserved_region().start(), sizeof(uint8_t)) >> HeapRegion::LogOfHRGrainBytes);
87 }
88
89 inline HeapWord* G1CollectedHeap::bottom_addr_for_region(uint index) const {
90 return _hrm.reserved().start() + index * HeapRegion::GrainWords;
91 }
92
93 template <class T>
94 inline HeapRegion* G1CollectedHeap::heap_region_containing_raw(const T addr) const {
95 assert(addr != NULL, "invariant");
96 assert(is_in_g1_reserved((const void*) addr),
97 err_msg("Address "PTR_FORMAT" is outside of the heap ranging from ["PTR_FORMAT" to "PTR_FORMAT")",
98 p2i((void*)addr), p2i(g1_reserved().start()), p2i(g1_reserved().end())));
99 return _hrm.addr_to_region((HeapWord*) addr);
100 }
101
102 template <class T>
103 inline HeapRegion* G1CollectedHeap::heap_region_containing(const T addr) const {
104 HeapRegion* hr = heap_region_containing_raw(addr);
105 if (hr->is_continues_humongous()) {
106 return hr->humongous_start_region();
107 }
108 return hr;
109 }
110
111 inline void G1CollectedHeap::reset_gc_time_stamp() {
112 _gc_time_stamp = 0;
113 OrderAccess::fence();
114 // Clear the cached CSet starting regions and time stamps.
115 // Their validity is dependent on the GC timestamp.
116 clear_cset_start_regions();
117 }
118
119 inline void G1CollectedHeap::increment_gc_time_stamp() {
120 ++_gc_time_stamp;
121 OrderAccess::fence();
122 }
123
124 inline void G1CollectedHeap::old_set_remove(HeapRegion* hr) {
125 _old_set.remove(hr);
126 }
127
128 inline bool G1CollectedHeap::obj_in_cs(oop obj) {
129 HeapRegion* r = _hrm.addr_to_region((HeapWord*) obj);
130 return r != NULL && r->in_collection_set();
131 }
132
133 inline HeapWord* G1CollectedHeap::attempt_allocation(size_t word_size,
134 uint* gc_count_before_ret,
135 uint* gclocker_retry_count_ret) {
136 assert_heap_not_locked_and_not_at_safepoint();
137 assert(!is_humongous(word_size), "attempt_allocation() should not "
138 "be called for humongous allocation requests");
139
140 AllocationContext_t context = AllocationContext::current();
141 HeapWord* result = _allocator->mutator_alloc_region(context)->attempt_allocation(word_size,
142 false /* bot_updates */);
143 if (result == NULL) {
144 result = attempt_allocation_slow(word_size,
145 context,
146 gc_count_before_ret,
147 gclocker_retry_count_ret);
148 }
149 assert_heap_not_locked();
150 if (result != NULL) {
151 dirty_young_block(result, word_size);
152 }
153 return result;
154 }
155
156 inline HeapWord* G1CollectedHeap::survivor_attempt_allocation(size_t word_size,
157 AllocationContext_t context) {
158 assert(!is_humongous(word_size),
159 "we should not be seeing humongous-size allocations in this path");
160
161 HeapWord* result = _allocator->survivor_gc_alloc_region(context)->attempt_allocation(word_size,
162 false /* bot_updates */);
163 if (result == NULL) {
164 MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
165 result = _allocator->survivor_gc_alloc_region(context)->attempt_allocation_locked(word_size,
166 false /* bot_updates */);
167 }
168 if (result != NULL) {
169 dirty_young_block(result, word_size);
170 }
171 return result;
172 }
173
174 inline HeapWord* G1CollectedHeap::old_attempt_allocation(size_t word_size,
175 AllocationContext_t context) {
176 assert(!is_humongous(word_size),
177 "we should not be seeing humongous-size allocations in this path");
178
179 HeapWord* result = _allocator->old_gc_alloc_region(context)->attempt_allocation(word_size,
180 true /* bot_updates */);
181 if (result == NULL) {
182 MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
183 result = _allocator->old_gc_alloc_region(context)->attempt_allocation_locked(word_size,
184 true /* bot_updates */);
185 }
186 return result;
187 }
188
189 // It dirties the cards that cover the block so that so that the post
190 // write barrier never queues anything when updating objects on this
191 // block. It is assumed (and in fact we assert) that the block
192 // belongs to a young region.
193 inline void
194 G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {
195 assert_heap_not_locked();
196
197 // Assign the containing region to containing_hr so that we don't
198 // have to keep calling heap_region_containing_raw() in the
199 // asserts below.
200 DEBUG_ONLY(HeapRegion* containing_hr = heap_region_containing_raw(start);)
201 assert(word_size > 0, "pre-condition");
202 assert(containing_hr->is_in(start), "it should contain start");
203 assert(containing_hr->is_young(), "it should be young");
204 assert(!containing_hr->is_humongous(), "it should not be humongous");
205
206 HeapWord* end = start + word_size;
207 assert(containing_hr->is_in(end - 1), "it should also contain end - 1");
208
209 MemRegion mr(start, end);
210 g1_barrier_set()->g1_mark_as_young(mr);
211 }
212
213 inline RefToScanQueue* G1CollectedHeap::task_queue(uint i) const {
214 return _task_queues->queue(i);
215 }
216
217 inline bool G1CollectedHeap::isMarkedPrev(oop obj) const {
218 return _cm->prevMarkBitMap()->isMarked((HeapWord *)obj);
219 }
220
221 inline bool G1CollectedHeap::isMarkedNext(oop obj) const {
222 return _cm->nextMarkBitMap()->isMarked((HeapWord *)obj);
223 }
224
225 // This is a fast test on whether a reference points into the
226 // collection set or not. Assume that the reference
227 // points into the heap.
228 inline bool G1CollectedHeap::is_in_cset(oop obj) {
229 bool ret = _in_cset_fast_test.is_in_cset((HeapWord*)obj);
230 // let's make sure the result is consistent with what the slower
231 // test returns
232 assert( ret || !obj_in_cs(obj), "sanity");
233 assert(!ret || obj_in_cs(obj), "sanity");
234 return ret;
235 }
236
237 bool G1CollectedHeap::is_in_cset(const HeapRegion* hr) {
238 return _in_cset_fast_test.is_in_cset(hr);
239 }
240
241 bool G1CollectedHeap::is_in_cset_or_humongous(const oop obj) {
242 return _in_cset_fast_test.is_in_cset_or_humongous((HeapWord*)obj);
243 }
244
245 InCSetState G1CollectedHeap::in_cset_state(const oop obj) {
246 return _in_cset_fast_test.at((HeapWord*)obj);
247 }
248
249 void G1CollectedHeap::register_humongous_region_with_cset(uint index) {
250 _in_cset_fast_test.set_humongous(index);
251 }
252
253 #ifndef PRODUCT
254 // Support for G1EvacuationFailureALot
255
256 inline bool
257 G1CollectedHeap::evacuation_failure_alot_for_gc_type(bool gcs_are_young,
258 bool during_initial_mark,
259 bool during_marking) {
260 bool res = false;
261 if (during_marking) {
262 res |= G1EvacuationFailureALotDuringConcMark;
263 }
264 if (during_initial_mark) {
265 res |= G1EvacuationFailureALotDuringInitialMark;
266 }
267 if (gcs_are_young) {
268 res |= G1EvacuationFailureALotDuringYoungGC;
269 } else {
270 // GCs are mixed
271 res |= G1EvacuationFailureALotDuringMixedGC;
272 }
273 return res;
274 }
275
276 inline void
277 G1CollectedHeap::set_evacuation_failure_alot_for_current_gc() {
278 if (G1EvacuationFailureALot) {
279 // Note we can't assert that _evacuation_failure_alot_for_current_gc
280 // is clear here. It may have been set during a previous GC but that GC
281 // did not copy enough objects (i.e. G1EvacuationFailureALotCount) to
282 // trigger an evacuation failure and clear the flags and and counts.
283
284 // Check if we have gone over the interval.
285 const size_t gc_num = total_collections();
286 const size_t elapsed_gcs = gc_num - _evacuation_failure_alot_gc_number;
287
288 _evacuation_failure_alot_for_current_gc = (elapsed_gcs >= G1EvacuationFailureALotInterval);
289
290 // Now check if G1EvacuationFailureALot is enabled for the current GC type.
291 const bool gcs_are_young = g1_policy()->gcs_are_young();
292 const bool during_im = g1_policy()->during_initial_mark_pause();
293 const bool during_marking = mark_in_progress();
294
295 _evacuation_failure_alot_for_current_gc &=
296 evacuation_failure_alot_for_gc_type(gcs_are_young,
297 during_im,
298 during_marking);
299 }
300 }
301
302 inline bool G1CollectedHeap::evacuation_should_fail() {
303 if (!G1EvacuationFailureALot || !_evacuation_failure_alot_for_current_gc) {
304 return false;
305 }
306 // G1EvacuationFailureALot is in effect for current GC
307 // Access to _evacuation_failure_alot_count is not atomic;
308 // the value does not have to be exact.
309 if (++_evacuation_failure_alot_count < G1EvacuationFailureALotCount) {
310 return false;
311 }
312 _evacuation_failure_alot_count = 0;
313 return true;
314 }
315
316 inline void G1CollectedHeap::reset_evacuation_should_fail() {
317 if (G1EvacuationFailureALot) {
318 _evacuation_failure_alot_gc_number = total_collections();
319 _evacuation_failure_alot_count = 0;
320 _evacuation_failure_alot_for_current_gc = false;
321 }
322 }
323 #endif // #ifndef PRODUCT
324
325 inline bool G1CollectedHeap::is_in_young(const oop obj) {
326 if (obj == NULL) {
327 return false;
328 }
329 return heap_region_containing(obj)->is_young();
330 }
331
332 // We don't need barriers for initializing stores to objects
333 // in the young gen: for the SATB pre-barrier, there is no
334 // pre-value that needs to be remembered; for the remembered-set
335 // update logging post-barrier, we don't maintain remembered set
336 // information for young gen objects.
337 inline bool G1CollectedHeap::can_elide_initializing_store_barrier(oop new_obj) {
338 return is_in_young(new_obj);
339 }
340
341 inline bool G1CollectedHeap::is_obj_dead(const oop obj) const {
342 if (obj == NULL) {
343 return false;
344 }
345 return is_obj_dead(obj, heap_region_containing(obj));
346 }
347
348 inline bool G1CollectedHeap::is_obj_ill(const oop obj) const {
349 if (obj == NULL) {
350 return false;
351 }
352 return is_obj_ill(obj, heap_region_containing(obj));
353 }
354
355 inline void G1CollectedHeap::set_humongous_reclaim_candidate(uint region, bool value) {
356 assert(_hrm.at(region)->is_starts_humongous(), "Must start a humongous object");
357 _humongous_reclaim_candidates.set_candidate(region, value);
358 }
359
360 inline bool G1CollectedHeap::is_humongous_reclaim_candidate(uint region) {
361 assert(_hrm.at(region)->is_starts_humongous(), "Must start a humongous object");
362 return _humongous_reclaim_candidates.is_candidate(region);
363 }
364
365 inline void G1CollectedHeap::set_humongous_is_live(oop obj) {
366 uint region = addr_to_region((HeapWord*)obj);
367 // Clear the flag in the humongous_reclaim_candidates table. Also
368 // reset the entry in the _in_cset_fast_test table so that subsequent references
369 // to the same humongous object do not go into the slow path again.
370 // This is racy, as multiple threads may at the same time enter here, but this
371 // is benign.
372 // During collection we only ever clear the "candidate" flag, and only ever clear the
373 // entry in the in_cset_fast_table.
374 // We only ever evaluate the contents of these tables (in the VM thread) after
375 // having synchronized the worker threads with the VM thread, or in the same
376 // thread (i.e. within the VM thread).
377 if (is_humongous_reclaim_candidate(region)) {
378 set_humongous_reclaim_candidate(region, false);
379 _in_cset_fast_test.clear_humongous(region);
380 }
381 }
382
383 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP