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. 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. 22 * 23 */ 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 35 inline 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 52 inline 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 76 inline 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 86 inline HeapWord* G1OffsetTableContigSpace::allocate(size_t word_size) { 87 size_t temp; 88 return allocate(word_size, word_size, &temp); 89 } 90 91 inline 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. 99 inline 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 } 105 106 inline HeapWord* G1OffsetTableContigSpace::block_start(const void* p) { 107 return _offsets.block_start(p); 108 } 109 110 inline HeapWord* 111 G1OffsetTableContigSpace::block_start_const(const void* p) const { 112 return _offsets.block_start_const(p); 113 } 114 115 inline bool 116 HeapRegion::block_is_obj(const HeapWord* p) const { 117 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 118 119 if (!this->is_in(p)) { 120 assert(is_continues_humongous(), "This case can only happen for humongous regions"); 121 return (p == humongous_start_region()->bottom()); 122 } 123 if (ClassUnloadingWithConcurrentMark) { 124 return !g1h->is_obj_dead(oop(p), this); 125 } 126 return p < top(); 127 } 128 129 inline size_t 130 HeapRegion::block_size(const HeapWord *addr) const { 131 if (addr == top()) { 132 return pointer_delta(end(), addr); 133 } 134 135 if (block_is_obj(addr)) { 136 return oop(addr)->size(); 137 } 138 139 assert(ClassUnloadingWithConcurrentMark, 140 "All blocks should be objects if G1 Class Unloading isn't used. " 141 "HR: [" PTR_FORMAT ", " PTR_FORMAT ", " PTR_FORMAT ") " 142 "addr: " PTR_FORMAT, 143 p2i(bottom()), p2i(top()), p2i(end()), p2i(addr)); 144 145 // Old regions' dead objects may have dead classes 146 // We need to find the next live object in some other 147 // manner than getting the oop size 148 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 149 HeapWord* next = g1h->concurrent_mark()->prevMarkBitMap()-> 150 getNextMarkedWordAddress(addr, prev_top_at_mark_start()); 151 152 assert(next > addr, "must get the next live object"); 153 return pointer_delta(next, addr); 154 } 155 156 inline HeapWord* HeapRegion::par_allocate_no_bot_updates(size_t min_word_size, 157 size_t desired_word_size, 158 size_t* actual_word_size) { 159 assert(is_young(), "we can only skip BOT updates on young regions"); 160 return par_allocate_impl(min_word_size, desired_word_size, actual_word_size); 161 } 162 163 inline HeapWord* HeapRegion::allocate_no_bot_updates(size_t word_size) { 164 size_t temp; 165 return allocate_no_bot_updates(word_size, word_size, &temp); 166 } 167 168 inline HeapWord* HeapRegion::allocate_no_bot_updates(size_t min_word_size, 169 size_t desired_word_size, 170 size_t* actual_word_size) { 171 assert(is_young(), "we can only skip BOT updates on young regions"); 172 return allocate_impl(min_word_size, desired_word_size, actual_word_size); 173 } 174 175 inline void HeapRegion::note_start_of_marking() { 176 _next_marked_bytes = 0; 177 _next_top_at_mark_start = top(); 178 } 179 180 inline void HeapRegion::note_end_of_marking() { 181 _prev_top_at_mark_start = _next_top_at_mark_start; 182 _prev_marked_bytes = _next_marked_bytes; 183 _next_marked_bytes = 0; 184 } 185 186 inline void HeapRegion::note_start_of_copying(bool during_initial_mark) { 187 if (is_survivor()) { 188 // This is how we always allocate survivors. 189 assert(_next_top_at_mark_start == bottom(), "invariant"); 190 } else { 191 if (during_initial_mark) { 192 // During initial-mark we'll explicitly mark any objects on old 193 // regions that are pointed to by roots. Given that explicit 194 // marks only make sense under NTAMS it'd be nice if we could 195 // check that condition if we wanted to. Given that we don't 196 // know where the top of this region will end up, we simply set 197 // NTAMS to the end of the region so all marks will be below 198 // NTAMS. We'll set it to the actual top when we retire this region. 199 _next_top_at_mark_start = end(); 200 } else { 201 // We could have re-used this old region as to-space over a 202 // couple of GCs since the start of the concurrent marking 203 // cycle. This means that [bottom,NTAMS) will contain objects 204 // copied up to and including initial-mark and [NTAMS, top) 205 // will contain objects copied during the concurrent marking cycle. 206 assert(top() >= _next_top_at_mark_start, "invariant"); 207 } 208 } 209 } 210 211 inline void HeapRegion::note_end_of_copying(bool during_initial_mark) { 212 if (is_survivor()) { 213 // This is how we always allocate survivors. 214 assert(_next_top_at_mark_start == bottom(), "invariant"); 215 } else { 216 if (during_initial_mark) { 217 // See the comment for note_start_of_copying() for the details 218 // on this. 219 assert(_next_top_at_mark_start == end(), "pre-condition"); 220 _next_top_at_mark_start = top(); 221 } else { 222 // See the comment for note_start_of_copying() for the details 223 // on this. 224 assert(top() >= _next_top_at_mark_start, "invariant"); 225 } 226 } 227 } 228 229 inline bool HeapRegion::in_collection_set() const { 230 return G1CollectedHeap::heap()->is_in_cset(this); 231 } 232 233 inline HeapRegion* HeapRegion::next_in_collection_set() const { 234 assert(in_collection_set(), "should only invoke on member of CS."); 235 assert(_next_in_special_set == NULL || 236 _next_in_special_set->in_collection_set(), 237 "Malformed CS."); 238 return _next_in_special_set; 239 } 240 241 void HeapRegion::set_next_in_collection_set(HeapRegion* r) { 242 assert(in_collection_set(), "should only invoke on member of CS."); 243 assert(r == NULL || r->in_collection_set(), "Malformed CS."); 244 _next_in_special_set = r; 245 } 246 247 #endif // SHARE_VM_GC_G1_HEAPREGION_INLINE_HPP