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.
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.
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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_raw(const T addr) const {
46 assert(addr != NULL, "invariant");
47 assert(_g1_reserved.contains((const void*) addr),
48 err_msg("Address "PTR_FORMAT" is outside of the heap ranging from ["PTR_FORMAT" to "PTR_FORMAT")",
49 p2i((void*)addr), p2i(_g1_reserved.start()), p2i(_g1_reserved.end())));
50 return _hrs.addr_to_region((HeapWord*) addr);
51 }
52
53 template <class T>
54 inline HeapRegion*
55 G1CollectedHeap::heap_region_containing(const T addr) const {
56 HeapRegion* hr = heap_region_containing_raw(addr);
57 if (hr->continuesHumongous()) {
58 return hr->humongous_start_region();
59 }
60 return hr;
61 }
62
63 inline void G1CollectedHeap::old_set_remove(HeapRegion* hr) {
64 _old_set.remove(hr);
65 }
66
67 inline bool G1CollectedHeap::obj_in_cs(oop obj) {
68 HeapRegion* r = _hrs.addr_to_region((HeapWord*) obj);
69 return r != NULL && r->in_collection_set();
70 }
71
72 inline HeapWord*
73 G1CollectedHeap::attempt_allocation(size_t word_size,
74 unsigned int* gc_count_before_ret,
75 int* gclocker_retry_count_ret) {
76 assert_heap_not_locked_and_not_at_safepoint();
77 assert(!isHumongous(word_size), "attempt_allocation() should not "
78 "be called for humongous allocation requests");
79
80 HeapWord* result = _mutator_alloc_region.attempt_allocation(word_size,
81 false /* bot_updates */);
82 if (result == NULL) {
83 result = attempt_allocation_slow(word_size,
84 gc_count_before_ret,
85 gclocker_retry_count_ret);
86 }
87 assert_heap_not_locked();
88 if (result != NULL) {
89 dirty_young_block(result, word_size);
90 }
91 return result;
92 }
93
94 inline HeapWord* G1CollectedHeap::survivor_attempt_allocation(size_t
95 word_size) {
96 assert(!isHumongous(word_size),
97 "we should not be seeing humongous-size allocations in this path");
98
99 HeapWord* result = _survivor_gc_alloc_region.attempt_allocation(word_size,
100 false /* bot_updates */);
101 if (result == NULL) {
102 MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
103 result = _survivor_gc_alloc_region.attempt_allocation_locked(word_size,
104 false /* bot_updates */);
105 }
106 if (result != NULL) {
107 dirty_young_block(result, word_size);
108 }
109 return result;
110 }
111
112 inline HeapWord* G1CollectedHeap::old_attempt_allocation(size_t word_size) {
113 assert(!isHumongous(word_size),
114 "we should not be seeing humongous-size allocations in this path");
115
116 HeapWord* result = _old_gc_alloc_region.attempt_allocation(word_size,
117 true /* bot_updates */);
118 if (result == NULL) {
119 MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
120 result = _old_gc_alloc_region.attempt_allocation_locked(word_size,
121 true /* bot_updates */);
122 }
123 return result;
124 }
125
126 // It dirties the cards that cover the block so that so that the post
127 // write barrier never queues anything when updating objects on this
128 // block. It is assumed (and in fact we assert) that the block
129 // belongs to a young region.
130 inline void
131 G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {
132 assert_heap_not_locked();
133
134 // Assign the containing region to containing_hr so that we don't
135 // have to keep calling heap_region_containing_raw() in the
136 // asserts below.
137 DEBUG_ONLY(HeapRegion* containing_hr = heap_region_containing_raw(start);)
138 assert(word_size > 0, "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 bool ret = _in_cset_fast_test.get_by_address((HeapWord*)obj);
168 // let's make sure the result is consistent with what the slower
169 // test returns
170 assert( ret || !obj_in_cs(obj), "sanity");
171 assert(!ret || obj_in_cs(obj), "sanity");
172 return ret;
173 }
174
175 #ifndef PRODUCT
176 // Support for G1EvacuationFailureALot
177
178 inline bool
179 G1CollectedHeap::evacuation_failure_alot_for_gc_type(bool gcs_are_young,
180 bool during_initial_mark,
181 bool during_marking) {
182 bool res = false;
183 if (during_marking) {
184 res |= G1EvacuationFailureALotDuringConcMark;
185 }
186 if (during_initial_mark) {
187 res |= G1EvacuationFailureALotDuringInitialMark;
188 }
189 if (gcs_are_young) {
190 res |= G1EvacuationFailureALotDuringYoungGC;
191 } else {
192 // GCs are mixed
193 res |= G1EvacuationFailureALotDuringMixedGC;
194 }
195 return res;
196 }
197
198 inline void
199 G1CollectedHeap::set_evacuation_failure_alot_for_current_gc() {
200 if (G1EvacuationFailureALot) {
201 // Note we can't assert that _evacuation_failure_alot_for_current_gc
202 // is clear here. It may have been set during a previous GC but that GC
203 // did not copy enough objects (i.e. G1EvacuationFailureALotCount) to
204 // trigger an evacuation failure and clear the flags and and counts.
205
206 // Check if we have gone over the interval.
207 const size_t gc_num = total_collections();
208 const size_t elapsed_gcs = gc_num - _evacuation_failure_alot_gc_number;
209
210 _evacuation_failure_alot_for_current_gc = (elapsed_gcs >= G1EvacuationFailureALotInterval);
211
212 // Now check if G1EvacuationFailureALot is enabled for the current GC type.
213 const bool gcs_are_young = g1_policy()->gcs_are_young();
214 const bool during_im = g1_policy()->during_initial_mark_pause();
215 const bool during_marking = mark_in_progress();
216
217 _evacuation_failure_alot_for_current_gc &=
218 evacuation_failure_alot_for_gc_type(gcs_are_young,
219 during_im,
220 during_marking);
221 }
222 }
223
224 inline bool
225 G1CollectedHeap::evacuation_should_fail() {
226 if (!G1EvacuationFailureALot || !_evacuation_failure_alot_for_current_gc) {
227 return false;
228 }
229 // G1EvacuationFailureALot is in effect for current GC
230 // Access to _evacuation_failure_alot_count is not atomic;
231 // the value does not have to be exact.
232 if (++_evacuation_failure_alot_count < G1EvacuationFailureALotCount) {
233 return false;
234 }
235 _evacuation_failure_alot_count = 0;
236 return true;
237 }
238
239 inline void G1CollectedHeap::reset_evacuation_should_fail() {
240 if (G1EvacuationFailureALot) {
241 _evacuation_failure_alot_gc_number = total_collections();
242 _evacuation_failure_alot_count = 0;
243 _evacuation_failure_alot_for_current_gc = false;
244 }
245 }
246 #endif // #ifndef PRODUCT
247
248 inline bool G1CollectedHeap::is_in_young(const oop obj) {
249 if (obj == NULL) {
250 return false;
251 }
252 return heap_region_containing(obj)->is_young();
253 }
254
255 // We don't need barriers for initializing stores to objects
256 // in the young gen: for the SATB pre-barrier, there is no
257 // pre-value that needs to be remembered; for the remembered-set
258 // update logging post-barrier, we don't maintain remembered set
259 // information for young gen objects.
260 inline bool G1CollectedHeap::can_elide_initializing_store_barrier(oop new_obj) {
261 return is_in_young(new_obj);
262 }
263
264 inline bool G1CollectedHeap::is_obj_dead(const oop obj) const {
265 if (obj == NULL) {
266 return false;
267 }
268 return is_obj_dead(obj, heap_region_containing(obj));
269 }
270
271 inline bool G1CollectedHeap::is_obj_ill(const oop obj) const {
272 if (obj == NULL) {
273 return false;
274 }
275 return is_obj_ill(obj, heap_region_containing(obj));
276 }
277
278 template <class T> inline void G1ParScanThreadState::immediate_rs_update(HeapRegion* from, T* p, int tid) {
279 if (!from->is_survivor()) {
280 _g1_rem->par_write_ref(from, p, tid);
281 }
282 }
283
284 template <class T> void G1ParScanThreadState::update_rs(HeapRegion* from, T* p, int tid) {
285 if (G1DeferredRSUpdate) {
286 deferred_rs_update(from, p, tid);
287 } else {
288 immediate_rs_update(from, p, tid);
289 }
290 }
291
292
293 inline void G1ParScanThreadState::do_oop_partial_array(oop* p) {
294 assert(has_partial_array_mask(p), "invariant");
295 oop from_obj = clear_partial_array_mask(p);
296
297 assert(Universe::heap()->is_in_reserved(from_obj), "must be in heap.");
298 assert(from_obj->is_objArray(), "must be obj array");
299 objArrayOop from_obj_array = objArrayOop(from_obj);
300 // The from-space object contains the real length.
301 int length = from_obj_array->length();
302
303 assert(from_obj->is_forwarded(), "must be forwarded");
304 oop to_obj = from_obj->forwardee();
305 assert(from_obj != to_obj, "should not be chunking self-forwarded objects");
306 objArrayOop to_obj_array = objArrayOop(to_obj);
307 // We keep track of the next start index in the length field of the
308 // to-space object.
309 int next_index = to_obj_array->length();
310 assert(0 <= next_index && next_index < length,
311 err_msg("invariant, next index: %d, length: %d", next_index, length));
312
313 int start = next_index;
314 int end = length;
315 int remainder = end - start;
316 // We'll try not to push a range that's smaller than ParGCArrayScanChunk.
317 if (remainder > 2 * ParGCArrayScanChunk) {
318 end = start + ParGCArrayScanChunk;
319 to_obj_array->set_length(end);
320 // Push the remainder before we process the range in case another
321 // worker has run out of things to do and can steal it.
322 oop* from_obj_p = set_partial_array_mask(from_obj);
323 push_on_queue(from_obj_p);
324 } else {
325 assert(length == end, "sanity");
326 // We'll process the final range for this object. Restore the length
327 // so that the heap remains parsable in case of evacuation failure.
328 to_obj_array->set_length(end);
329 }
330 _scanner.set_region(_g1h->heap_region_containing_raw(to_obj));
331 // Process indexes [start,end). It will also process the header
332 // along with the first chunk (i.e., the chunk with start == 0).
333 // Note that at this point the length field of to_obj_array is not
334 // correct given that we are using it to keep track of the next
335 // start index. oop_iterate_range() (thankfully!) ignores the length
336 // field and only relies on the start / end parameters. It does
337 // however return the size of the object which will be incorrect. So
338 // we have to ignore it even if we wanted to use it.
339 to_obj_array->oop_iterate_range(&_scanner, start, end);
340 }
341
342 template <class T> inline void G1ParScanThreadState::deal_with_reference(T* ref_to_scan) {
343 if (!has_partial_array_mask(ref_to_scan)) {
344 // Note: we can use "raw" versions of "region_containing" because
345 // "obj_to_scan" is definitely in the heap, and is not in a
346 // humongous region.
347 HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan);
348 do_oop_evac(ref_to_scan, r);
349 } else {
350 do_oop_partial_array((oop*)ref_to_scan);
351 }
352 }
353
354 inline void G1ParScanThreadState::deal_with_reference(StarTask ref) {
355 assert(verify_task(ref), "sanity");
356 if (ref.is_narrow()) {
357 deal_with_reference((narrowOop*)ref);
358 } else {
359 deal_with_reference((oop*)ref);
360 }
361 }
362
363 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP