heapRegion.inline.hpp revision 8877:859d0f2dca76 
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24
25#ifndef SHARE_VM_GC_G1_HEAPREGION_INLINE_HPP
26#define SHARE_VM_GC_G1_HEAPREGION_INLINE_HPP
27
28#include "gc/g1/g1BlockOffsetTable.inline.hpp"
29#include "gc/g1/g1CollectedHeap.inline.hpp"
30#include "gc/g1/heapRegion.hpp"
31#include "gc/shared/space.hpp"
32#include "oops/oop.inline.hpp"
33#include "runtime/atomic.inline.hpp"
34
35inline HeapWord* G1OffsetTableContigSpace::allocate_impl(size_t min_word_size,
36                                                         size_t desired_word_size,
37                                                         size_t* actual_size) {
38  HeapWord* obj = top();
39  size_t available = pointer_delta(end(), obj);
40  size_t want_to_allocate = MIN2(available, desired_word_size);
41  if (want_to_allocate >= min_word_size) {
42    HeapWord* new_top = obj + want_to_allocate;
43    set_top(new_top);
44    assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
45    *actual_size = want_to_allocate;
46    return obj;
47  } else {
48    return NULL;
49  }
50}
51
52inline HeapWord* G1OffsetTableContigSpace::par_allocate_impl(size_t min_word_size,
53                                                             size_t desired_word_size,
54                                                             size_t* actual_size) {
55  do {
56    HeapWord* obj = top();
57    size_t available = pointer_delta(end(), obj);
58    size_t want_to_allocate = MIN2(available, desired_word_size);
59    if (want_to_allocate >= min_word_size) {
60      HeapWord* new_top = obj + want_to_allocate;
61      HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
62      // result can be one of two:
63      //  the old top value: the exchange succeeded
64      //  otherwise: the new value of the top is returned.
65      if (result == obj) {
66        assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
67        *actual_size = want_to_allocate;
68        return obj;
69      }
70    } else {
71      return NULL;
72    }
73  } while (true);
74}
75
76inline HeapWord* G1OffsetTableContigSpace::allocate(size_t min_word_size,
77                                                    size_t desired_word_size,
78                                                    size_t* actual_size) {
79  HeapWord* res = allocate_impl(min_word_size, desired_word_size, actual_size);
80  if (res != NULL) {
81    _offsets.alloc_block(res, *actual_size);
82  }
83  return res;
84}
85
86inline HeapWord* G1OffsetTableContigSpace::allocate(size_t word_size) {
87  size_t temp;
88  return allocate(word_size, word_size, &temp);
89}
90
91inline HeapWord* G1OffsetTableContigSpace::par_allocate(size_t word_size) {
92  size_t temp;
93  return par_allocate(word_size, word_size, &temp);
94}
95
96// Because of the requirement of keeping "_offsets" up to date with the
97// allocations, we sequentialize these with a lock.  Therefore, best if
98// this is used for larger LAB allocations only.
99inline HeapWord* G1OffsetTableContigSpace::par_allocate(size_t min_word_size,
100                                                        size_t desired_word_size,
101                                                        size_t* actual_size) {
102  MutexLocker x(&_par_alloc_lock);
103  return allocate(min_word_size, desired_word_size, actual_size);
104}
105
106inline HeapWord* G1OffsetTableContigSpace::block_start(const void* p) {
107  return _offsets.block_start(p);
108}
109
110inline HeapWord*
111G1OffsetTableContigSpace::block_start_const(const void* p) const {
112  return _offsets.block_start_const(p);
113}
114
115inline bool
116HeapRegion::block_is_obj(const HeapWord* p) const {
117  G1CollectedHeap* g1h = G1CollectedHeap::heap();
118  if (ClassUnloadingWithConcurrentMark) {
119    return !g1h->is_obj_dead(oop(p), this);
120  }
121  return p < top();
122}
123
124inline size_t
125HeapRegion::block_size(const HeapWord *addr) const {
126  if (addr == top()) {
127    return pointer_delta(end(), addr);
128  }
129
130  if (block_is_obj(addr)) {
131    return oop(addr)->size();
132  }
133
134  assert(ClassUnloadingWithConcurrentMark,
135      err_msg("All blocks should be objects if G1 Class Unloading isn't used. "
136              "HR: [" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT ") "
137              "addr: " PTR_FORMAT,
138              p2i(bottom()), p2i(top()), p2i(end()), p2i(addr)));
139
140  // Old regions' dead objects may have dead classes
141  // We need to find the next live object in some other
142  // manner than getting the oop size
143  G1CollectedHeap* g1h = G1CollectedHeap::heap();
144  HeapWord* next = g1h->concurrent_mark()->prevMarkBitMap()->
145      getNextMarkedWordAddress(addr, prev_top_at_mark_start());
146
147  assert(next > addr, "must get the next live object");
148  return pointer_delta(next, addr);
149}
150
151inline HeapWord* HeapRegion::par_allocate_no_bot_updates(size_t min_word_size,
152                                                         size_t desired_word_size,
153                                                         size_t* actual_word_size) {
154  assert(is_young(), "we can only skip BOT updates on young regions");
155  return par_allocate_impl(min_word_size, desired_word_size, actual_word_size);
156}
157
158inline HeapWord* HeapRegion::allocate_no_bot_updates(size_t word_size) {
159  size_t temp;
160  return allocate_no_bot_updates(word_size, word_size, &temp);
161}
162
163inline HeapWord* HeapRegion::allocate_no_bot_updates(size_t min_word_size,
164                                                     size_t desired_word_size,
165                                                     size_t* actual_word_size) {
166  assert(is_young(), "we can only skip BOT updates on young regions");
167  return allocate_impl(min_word_size, desired_word_size, actual_word_size);
168}
169
170inline void HeapRegion::note_start_of_marking() {
171  _next_marked_bytes = 0;
172  _next_top_at_mark_start = top();
173}
174
175inline void HeapRegion::note_end_of_marking() {
176  _prev_top_at_mark_start = _next_top_at_mark_start;
177  _prev_marked_bytes = _next_marked_bytes;
178  _next_marked_bytes = 0;
179
180  assert(_prev_marked_bytes <=
181         (size_t) pointer_delta(prev_top_at_mark_start(), bottom()) *
182         HeapWordSize, "invariant");
183}
184
185inline void HeapRegion::note_start_of_copying(bool during_initial_mark) {
186  if (is_survivor()) {
187    // This is how we always allocate survivors.
188    assert(_next_top_at_mark_start == bottom(), "invariant");
189  } else {
190    if (during_initial_mark) {
191      // During initial-mark we'll explicitly mark any objects on old
192      // regions that are pointed to by roots. Given that explicit
193      // marks only make sense under NTAMS it'd be nice if we could
194      // check that condition if we wanted to. Given that we don't
195      // know where the top of this region will end up, we simply set
196      // NTAMS to the end of the region so all marks will be below
197      // NTAMS. We'll set it to the actual top when we retire this region.
198      _next_top_at_mark_start = end();
199    } else {
200      // We could have re-used this old region as to-space over a
201      // couple of GCs since the start of the concurrent marking
202      // cycle. This means that [bottom,NTAMS) will contain objects
203      // copied up to and including initial-mark and [NTAMS, top)
204      // will contain objects copied during the concurrent marking cycle.
205      assert(top() >= _next_top_at_mark_start, "invariant");
206    }
207  }
208}
209
210inline void HeapRegion::note_end_of_copying(bool during_initial_mark) {
211  if (is_survivor()) {
212    // This is how we always allocate survivors.
213    assert(_next_top_at_mark_start == bottom(), "invariant");
214  } else {
215    if (during_initial_mark) {
216      // See the comment for note_start_of_copying() for the details
217      // on this.
218      assert(_next_top_at_mark_start == end(), "pre-condition");
219      _next_top_at_mark_start = top();
220    } else {
221      // See the comment for note_start_of_copying() for the details
222      // on this.
223      assert(top() >= _next_top_at_mark_start, "invariant");
224    }
225  }
226}
227
228inline bool HeapRegion::in_collection_set() const {
229  return G1CollectedHeap::heap()->is_in_cset(this);
230}
231
232inline HeapRegion* HeapRegion::next_in_collection_set() const {
233  assert(in_collection_set(), "should only invoke on member of CS.");
234  assert(_next_in_special_set == NULL ||
235         _next_in_special_set->in_collection_set(),
236         "Malformed CS.");
237  return _next_in_special_set;
238}
239
240void HeapRegion::set_next_in_collection_set(HeapRegion* r) {
241  assert(in_collection_set(), "should only invoke on member of CS.");
242  assert(r == NULL || r->in_collection_set(), "Malformed CS.");
243  _next_in_special_set = r;
244}
245
246#endif // SHARE_VM_GC_G1_HEAPREGION_INLINE_HPP
247