1 /*
2 * Copyright (c) 2001, 2013, 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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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.
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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/g1RemSet.inline.hpp"
33 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
34 #include "gc_implementation/g1/heapRegionSet.inline.hpp"
35 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
36 #include "utilities/taskqueue.hpp"
37
38 // Inline functions for G1CollectedHeap
39
40 // Return the region with the given index. It assumes the index is valid.
41 inline HeapRegion* G1CollectedHeap::region_at(uint index) const { return _hrs.at(index); }
42
43 template <class T>
44 inline HeapRegion*
45 G1CollectedHeap::heap_region_containing(const T addr) const {
46 HeapRegion* hr = _hrs.addr_to_region((HeapWord*) addr);
47 // hr can be null if addr in perm_gen
48 if (hr != NULL && hr->continuesHumongous()) {
49 hr = hr->humongous_start_region();
50 }
51 return hr;
52 }
53
54 template <class T>
55 inline HeapRegion*
56 G1CollectedHeap::heap_region_containing_raw(const T addr) const {
57 assert(_g1_reserved.contains((const void*) addr), "invariant");
58 HeapRegion* res = _hrs.addr_to_region_unsafe((HeapWord*) addr);
59 return res;
60 }
61
62 inline void G1CollectedHeap::old_set_remove(HeapRegion* hr) {
63 _old_set.remove(hr);
64 }
65
66 inline bool G1CollectedHeap::obj_in_cs(oop obj) {
67 HeapRegion* r = _hrs.addr_to_region((HeapWord*) obj);
68 return r != NULL && r->in_collection_set();
69 }
70
71 inline HeapWord*
72 G1CollectedHeap::attempt_allocation(size_t word_size,
73 unsigned int* gc_count_before_ret,
74 int* gclocker_retry_count_ret) {
75 assert_heap_not_locked_and_not_at_safepoint();
76 assert(!isHumongous(word_size), "attempt_allocation() should not "
77 "be called for humongous allocation requests");
78
79 HeapWord* result = _mutator_alloc_region.attempt_allocation(word_size,
80 false /* bot_updates */);
81 if (result == NULL) {
82 result = attempt_allocation_slow(word_size,
83 gc_count_before_ret,
84 gclocker_retry_count_ret);
85 }
86 assert_heap_not_locked();
87 if (result != NULL) {
88 dirty_young_block(result, word_size);
89 }
90 return result;
91 }
92
93 inline HeapWord* G1CollectedHeap::survivor_attempt_allocation(size_t
94 word_size) {
95 assert(!isHumongous(word_size),
96 "we should not be seeing humongous-size allocations in this path");
97
98 HeapWord* result = _survivor_gc_alloc_region.attempt_allocation(word_size,
99 false /* bot_updates */);
100 if (result == NULL) {
101 MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
102 result = _survivor_gc_alloc_region.attempt_allocation_locked(word_size,
103 false /* bot_updates */);
104 }
105 if (result != NULL) {
106 dirty_young_block(result, word_size);
107 }
108 return result;
109 }
110
111 inline HeapWord* G1CollectedHeap::old_attempt_allocation(size_t word_size) {
112 assert(!isHumongous(word_size),
113 "we should not be seeing humongous-size allocations in this path");
114
115 HeapWord* result = _old_gc_alloc_region.attempt_allocation(word_size,
116 true /* bot_updates */);
117 if (result == NULL) {
118 MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
119 result = _old_gc_alloc_region.attempt_allocation_locked(word_size,
120 true /* bot_updates */);
121 }
122 return result;
123 }
124
125 // It dirties the cards that cover the block so that so that the post
126 // write barrier never queues anything when updating objects on this
127 // block. It is assumed (and in fact we assert) that the block
128 // belongs to a young region.
129 inline void
130 G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {
131 assert_heap_not_locked();
132
133 // Assign the containing region to containing_hr so that we don't
134 // have to keep calling heap_region_containing_raw() in the
135 // asserts below.
136 DEBUG_ONLY(HeapRegion* containing_hr = heap_region_containing_raw(start);)
137 assert(containing_hr != NULL && start != NULL && word_size > 0,
138 "pre-condition");
139 assert(containing_hr->is_in(start), "it should contain start");
140 assert(containing_hr->is_young(), "it should be young");
141 assert(!containing_hr->isHumongous(), "it should not be humongous");
142
143 HeapWord* end = start + word_size;
144 assert(containing_hr->is_in(end - 1), "it should also contain end - 1");
145
146 MemRegion mr(start, end);
147 g1_barrier_set()->g1_mark_as_young(mr);
148 }
149
150 inline RefToScanQueue* G1CollectedHeap::task_queue(int i) const {
151 return _task_queues->queue(i);
152 }
153
154 inline bool G1CollectedHeap::isMarkedPrev(oop obj) const {
155 return _cm->prevMarkBitMap()->isMarked((HeapWord *)obj);
156 }
157
158 inline bool G1CollectedHeap::isMarkedNext(oop obj) const {
159 return _cm->nextMarkBitMap()->isMarked((HeapWord *)obj);
160 }
161
162
163 // This is a fast test on whether a reference points into the
164 // collection set or not. Assume that the reference
165 // points into the heap.
166 inline bool G1CollectedHeap::in_cset_fast_test(oop obj) {
167 assert(_in_cset_fast_test != NULL, "sanity");
168 assert(_g1_committed.contains((HeapWord*) obj), err_msg("Given reference outside of heap, is "PTR_FORMAT, (HeapWord*)obj));
169 // no need to subtract the bottom of the heap from obj,
170 // _in_cset_fast_test is biased
171 uintx index = cast_from_oop<uintx>(obj) >> HeapRegion::LogOfHRGrainBytes;
172 bool ret = _in_cset_fast_test[index];
173 // let's make sure the result is consistent with what the slower
174 // test returns
175 assert( ret || !obj_in_cs(obj), "sanity");
176 assert(!ret || obj_in_cs(obj), "sanity");
177 return ret;
178 }
179
180 #ifndef PRODUCT
181 // Support for G1EvacuationFailureALot
182
183 inline bool
184 G1CollectedHeap::evacuation_failure_alot_for_gc_type(bool gcs_are_young,
185 bool during_initial_mark,
186 bool during_marking) {
187 bool res = false;
188 if (during_marking) {
189 res |= G1EvacuationFailureALotDuringConcMark;
190 }
191 if (during_initial_mark) {
192 res |= G1EvacuationFailureALotDuringInitialMark;
193 }
194 if (gcs_are_young) {
195 res |= G1EvacuationFailureALotDuringYoungGC;
196 } else {
197 // GCs are mixed
198 res |= G1EvacuationFailureALotDuringMixedGC;
199 }
200 return res;
201 }
202
203 inline void
204 G1CollectedHeap::set_evacuation_failure_alot_for_current_gc() {
205 if (G1EvacuationFailureALot) {
206 // Note we can't assert that _evacuation_failure_alot_for_current_gc
207 // is clear here. It may have been set during a previous GC but that GC
208 // did not copy enough objects (i.e. G1EvacuationFailureALotCount) to
209 // trigger an evacuation failure and clear the flags and and counts.
210
211 // Check if we have gone over the interval.
212 const size_t gc_num = total_collections();
213 const size_t elapsed_gcs = gc_num - _evacuation_failure_alot_gc_number;
214
215 _evacuation_failure_alot_for_current_gc = (elapsed_gcs >= G1EvacuationFailureALotInterval);
216
217 // Now check if G1EvacuationFailureALot is enabled for the current GC type.
218 const bool gcs_are_young = g1_policy()->gcs_are_young();
219 const bool during_im = g1_policy()->during_initial_mark_pause();
220 const bool during_marking = mark_in_progress();
221
222 _evacuation_failure_alot_for_current_gc &=
223 evacuation_failure_alot_for_gc_type(gcs_are_young,
224 during_im,
225 during_marking);
226 }
227 }
228
229 inline bool
230 G1CollectedHeap::evacuation_should_fail() {
231 if (!G1EvacuationFailureALot || !_evacuation_failure_alot_for_current_gc) {
232 return false;
233 }
234 // G1EvacuationFailureALot is in effect for current GC
235 // Access to _evacuation_failure_alot_count is not atomic;
236 // the value does not have to be exact.
237 if (++_evacuation_failure_alot_count < G1EvacuationFailureALotCount) {
238 return false;
239 }
240 _evacuation_failure_alot_count = 0;
241 return true;
242 }
243
244 inline void G1CollectedHeap::reset_evacuation_should_fail() {
245 if (G1EvacuationFailureALot) {
246 _evacuation_failure_alot_gc_number = total_collections();
247 _evacuation_failure_alot_count = 0;
248 _evacuation_failure_alot_for_current_gc = false;
249 }
250 }
251 #endif // #ifndef PRODUCT
252
253 inline bool G1CollectedHeap::is_in_young(const oop obj) {
254 HeapRegion* hr = heap_region_containing(obj);
255 return hr != NULL && hr->is_young();
256 }
257
258 // We don't need barriers for initializing stores to objects
259 // in the young gen: for the SATB pre-barrier, there is no
260 // pre-value that needs to be remembered; for the remembered-set
261 // update logging post-barrier, we don't maintain remembered set
262 // information for young gen objects.
263 inline bool G1CollectedHeap::can_elide_initializing_store_barrier(oop new_obj) {
264 return is_in_young(new_obj);
265 }
266
267 inline bool G1CollectedHeap::is_obj_dead(const oop obj) const {
268 const HeapRegion* hr = heap_region_containing(obj);
269 if (hr == NULL) {
270 if (obj == NULL) return false;
271 else return true;
272 }
273 else return is_obj_dead(obj, hr);
274 }
275
276 inline bool G1CollectedHeap::is_obj_ill(const oop obj) const {
277 const HeapRegion* hr = heap_region_containing(obj);
278 if (hr == NULL) {
279 if (obj == NULL) return false;
280 else return true;
281 }
282 else return is_obj_ill(obj, hr);
283 }
284
285 template <class T> inline void G1ParScanThreadState::immediate_rs_update(HeapRegion* from, T* p, int tid) {
286 if (!from->is_survivor()) {
287 _g1_rem->par_write_ref(from, p, tid);
288 }
289 }
290
291 template <class T> void G1ParScanThreadState::update_rs(HeapRegion* from, T* p, int tid) {
292 if (G1DeferredRSUpdate) {
293 deferred_rs_update(from, p, tid);
294 } else {
295 immediate_rs_update(from, p, tid);
296 }
297 }
298
299
300 inline void G1ParScanThreadState::do_oop_partial_array(oop* p) {
301 assert(has_partial_array_mask(p), "invariant");
302 oop from_obj = clear_partial_array_mask(p);
303
304 assert(Universe::heap()->is_in_reserved(from_obj), "must be in heap.");
305 assert(from_obj->is_objArray(), "must be obj array");
306 objArrayOop from_obj_array = objArrayOop(from_obj);
307 // The from-space object contains the real length.
308 int length = from_obj_array->length();
309
310 assert(from_obj->is_forwarded(), "must be forwarded");
311 oop to_obj = from_obj->forwardee();
312 assert(from_obj != to_obj, "should not be chunking self-forwarded objects");
313 objArrayOop to_obj_array = objArrayOop(to_obj);
314 // We keep track of the next start index in the length field of the
315 // to-space object.
316 int next_index = to_obj_array->length();
317 assert(0 <= next_index && next_index < length,
318 err_msg("invariant, next index: %d, length: %d", next_index, length));
319
320 int start = next_index;
321 int end = length;
322 int remainder = end - start;
323 // We'll try not to push a range that's smaller than ParGCArrayScanChunk.
324 if (remainder > 2 * ParGCArrayScanChunk) {
325 end = start + ParGCArrayScanChunk;
326 to_obj_array->set_length(end);
327 // Push the remainder before we process the range in case another
328 // worker has run out of things to do and can steal it.
329 oop* from_obj_p = set_partial_array_mask(from_obj);
330 push_on_queue(from_obj_p);
331 } else {
332 assert(length == end, "sanity");
333 // We'll process the final range for this object. Restore the length
334 // so that the heap remains parsable in case of evacuation failure.
335 to_obj_array->set_length(end);
336 }
337 _scanner.set_region(_g1h->heap_region_containing_raw(to_obj));
338 // Process indexes [start,end). It will also process the header
339 // along with the first chunk (i.e., the chunk with start == 0).
340 // Note that at this point the length field of to_obj_array is not
341 // correct given that we are using it to keep track of the next
342 // start index. oop_iterate_range() (thankfully!) ignores the length
343 // field and only relies on the start / end parameters. It does
344 // however return the size of the object which will be incorrect. So
345 // we have to ignore it even if we wanted to use it.
346 to_obj_array->oop_iterate_range(&_scanner, start, end);
347 }
348
349 template <class T> inline void G1ParScanThreadState::deal_with_reference(T* ref_to_scan) {
350 if (!has_partial_array_mask(ref_to_scan)) {
351 // Note: we can use "raw" versions of "region_containing" because
352 // "obj_to_scan" is definitely in the heap, and is not in a
353 // humongous region.
354 HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan);
355 do_oop_evac(ref_to_scan, r);
356 } else {
357 do_oop_partial_array((oop*)ref_to_scan);
358 }
359 }
360
361 inline void G1ParScanThreadState::deal_with_reference(StarTask ref) {
362 assert(verify_task(ref), "sanity");
363 if (ref.is_narrow()) {
364 deal_with_reference((narrowOop*)ref);
365 } else {
366 deal_with_reference((oop*)ref);
367 }
368 }
369
370 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP