1 /* 2 * Copyright (c) 2005, 2010, 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 #include "precompiled.hpp" 26 #include "gc_implementation/parallelScavenge/parMarkBitMap.hpp" 27 #include "gc_implementation/parallelScavenge/parMarkBitMap.inline.hpp" 28 #include "gc_implementation/parallelScavenge/psParallelCompact.hpp" 29 #include "oops/oop.inline.hpp" 30 #include "runtime/os.hpp" 31 #include "utilities/bitMap.inline.hpp" 32 #ifdef TARGET_OS_FAMILY_linux 33 # include "os_linux.inline.hpp" 34 #endif 35 #ifdef TARGET_OS_FAMILY_solaris 36 # include "os_solaris.inline.hpp" 37 #endif 38 #ifdef TARGET_OS_FAMILY_windows 39 # include "os_windows.inline.hpp" 40 #endif 41 42 bool 43 ParMarkBitMap::initialize(MemRegion covered_region) 44 { 45 const idx_t bits = bits_required(covered_region); 46 // The bits will be divided evenly between two bitmaps; each of them should be 47 // an integral number of words. 48 assert(bits % (BitsPerWord * 2) == 0, "region size unaligned"); 49 50 const size_t words = bits / BitsPerWord; 51 const size_t raw_bytes = words * sizeof(idx_t); 52 const size_t page_sz = os::page_size_for_region(raw_bytes, raw_bytes, 10); 53 const size_t granularity = os::vm_allocation_granularity(); 54 const size_t bytes = align_size_up(raw_bytes, MAX2(page_sz, granularity)); 55 56 const size_t rs_align = page_sz == (size_t) os::vm_page_size() ? 0 : 57 MAX2(page_sz, granularity); 58 ReservedSpace rs(bytes, rs_align, rs_align > 0); 59 os::trace_page_sizes("par bitmap", raw_bytes, raw_bytes, page_sz, 60 rs.base(), rs.size()); 61 _virtual_space = new PSVirtualSpace(rs, page_sz); 62 if (_virtual_space != NULL && _virtual_space->expand_by(bytes)) { 63 _region_start = covered_region.start(); 64 _region_size = covered_region.word_size(); 65 idx_t* map = (idx_t*)_virtual_space->reserved_low_addr(); 66 _beg_bits.set_map(map); 67 _beg_bits.set_size(bits / 2); 68 _end_bits.set_map(map + words / 2); 69 _end_bits.set_size(bits / 2); 70 return true; 71 } 72 73 _region_start = 0; 74 _region_size = 0; 75 if (_virtual_space != NULL) { 76 delete _virtual_space; 77 _virtual_space = NULL; 78 // Release memory reserved in the space. 79 rs.release(); 80 } 81 return false; 82 } 83 84 #ifdef ASSERT 85 extern size_t mark_bitmap_count; 86 extern size_t mark_bitmap_size; 87 #endif // #ifdef ASSERT 88 89 bool 90 ParMarkBitMap::mark_obj(HeapWord* addr, size_t size) 91 { 92 const idx_t beg_bit = addr_to_bit(addr); 93 if (_beg_bits.par_set_bit(beg_bit)) { 94 const idx_t end_bit = addr_to_bit(addr + size - 1); 95 bool end_bit_ok = _end_bits.par_set_bit(end_bit); 96 assert(end_bit_ok, "concurrency problem"); 97 DEBUG_ONLY(Atomic::inc_ptr(&mark_bitmap_count)); 98 DEBUG_ONLY(Atomic::add_ptr(size, &mark_bitmap_size)); 99 return true; 100 } 101 return false; 102 } 103 104 size_t 105 ParMarkBitMap::live_words_in_range(HeapWord* beg_addr, HeapWord* end_addr) const 106 { 107 assert(beg_addr <= end_addr, "bad range"); 108 109 idx_t live_bits = 0; 110 111 // The bitmap routines require the right boundary to be word-aligned. 112 const idx_t end_bit = addr_to_bit(end_addr); 113 const idx_t range_end = BitMap::word_align_up(end_bit); 114 115 idx_t beg_bit = find_obj_beg(addr_to_bit(beg_addr), range_end); 116 while (beg_bit < end_bit) { 117 idx_t tmp_end = find_obj_end(beg_bit, range_end); 118 if (tmp_end < end_bit) { 119 live_bits += tmp_end - beg_bit + 1; 120 beg_bit = find_obj_beg(tmp_end + 1, range_end); 121 } else { 122 live_bits += end_bit - beg_bit; // No + 1 here; end_bit is not counted. 123 return bits_to_words(live_bits); 124 } 125 } 126 return bits_to_words(live_bits); 127 } 128 129 size_t ParMarkBitMap::live_words_in_range(HeapWord* beg_addr, oop end_obj) const 130 { 131 assert(beg_addr <= (HeapWord*)end_obj, "bad range"); 132 assert(is_marked(end_obj), "end_obj must be live"); 133 134 idx_t live_bits = 0; 135 136 // The bitmap routines require the right boundary to be word-aligned. 137 const idx_t end_bit = addr_to_bit((HeapWord*)end_obj); 138 const idx_t range_end = BitMap::word_align_up(end_bit); 139 140 idx_t beg_bit = find_obj_beg(addr_to_bit(beg_addr), range_end); 141 while (beg_bit < end_bit) { 142 idx_t tmp_end = find_obj_end(beg_bit, range_end); 143 assert(tmp_end < end_bit, "missing end bit"); 144 live_bits += tmp_end - beg_bit + 1; 145 beg_bit = find_obj_beg(tmp_end + 1, range_end); 146 } 147 return bits_to_words(live_bits); 148 } 149 150 ParMarkBitMap::IterationStatus 151 ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure, 152 idx_t range_beg, idx_t range_end) const 153 { 154 DEBUG_ONLY(verify_bit(range_beg);) 155 DEBUG_ONLY(verify_bit(range_end);) 156 assert(range_beg <= range_end, "live range invalid"); 157 158 // The bitmap routines require the right boundary to be word-aligned. 159 const idx_t search_end = BitMap::word_align_up(range_end); 160 161 idx_t cur_beg = find_obj_beg(range_beg, search_end); 162 while (cur_beg < range_end) { 163 const idx_t cur_end = find_obj_end(cur_beg, search_end); 164 if (cur_end >= range_end) { 165 // The obj ends outside the range. 166 live_closure->set_source(bit_to_addr(cur_beg)); 167 return incomplete; 168 } 169 170 const size_t size = obj_size(cur_beg, cur_end); 171 IterationStatus status = live_closure->do_addr(bit_to_addr(cur_beg), size); 172 if (status != incomplete) { 173 assert(status == would_overflow || status == full, "sanity"); 174 return status; 175 } 176 177 // Successfully processed the object; look for the next object. 178 cur_beg = find_obj_beg(cur_end + 1, search_end); 179 } 180 181 live_closure->set_source(bit_to_addr(range_end)); 182 return complete; 183 } 184 185 ParMarkBitMap::IterationStatus 186 ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure, 187 ParMarkBitMapClosure* dead_closure, 188 idx_t range_beg, idx_t range_end, 189 idx_t dead_range_end) const 190 { 191 DEBUG_ONLY(verify_bit(range_beg);) 192 DEBUG_ONLY(verify_bit(range_end);) 193 DEBUG_ONLY(verify_bit(dead_range_end);) 194 assert(range_beg <= range_end, "live range invalid"); 195 assert(range_end <= dead_range_end, "dead range invalid"); 196 197 // The bitmap routines require the right boundary to be word-aligned. 198 const idx_t live_search_end = BitMap::word_align_up(range_end); 199 const idx_t dead_search_end = BitMap::word_align_up(dead_range_end); 200 201 idx_t cur_beg = range_beg; 202 if (range_beg < range_end && is_unmarked(range_beg)) { 203 // The range starts with dead space. Look for the next object, then fill. 204 cur_beg = find_obj_beg(range_beg + 1, dead_search_end); 205 const idx_t dead_space_end = MIN2(cur_beg - 1, dead_range_end - 1); 206 const size_t size = obj_size(range_beg, dead_space_end); 207 dead_closure->do_addr(bit_to_addr(range_beg), size); 208 } 209 210 while (cur_beg < range_end) { 211 const idx_t cur_end = find_obj_end(cur_beg, live_search_end); 212 if (cur_end >= range_end) { 213 // The obj ends outside the range. 214 live_closure->set_source(bit_to_addr(cur_beg)); 215 return incomplete; 216 } 217 218 const size_t size = obj_size(cur_beg, cur_end); 219 IterationStatus status = live_closure->do_addr(bit_to_addr(cur_beg), size); 220 if (status != incomplete) { 221 assert(status == would_overflow || status == full, "sanity"); 222 return status; 223 } 224 225 // Look for the start of the next object. 226 const idx_t dead_space_beg = cur_end + 1; 227 cur_beg = find_obj_beg(dead_space_beg, dead_search_end); 228 if (cur_beg > dead_space_beg) { 229 // Found dead space; compute the size and invoke the dead closure. 230 const idx_t dead_space_end = MIN2(cur_beg - 1, dead_range_end - 1); 231 const size_t size = obj_size(dead_space_beg, dead_space_end); 232 dead_closure->do_addr(bit_to_addr(dead_space_beg), size); 233 } 234 } 235 236 live_closure->set_source(bit_to_addr(range_end)); 237 return complete; 238 } 239 240 #ifndef PRODUCT 241 void ParMarkBitMap::reset_counters() 242 { 243 _cas_tries = _cas_retries = _cas_by_another = 0; 244 } 245 #endif // #ifndef PRODUCT 246 247 #ifdef ASSERT 248 void ParMarkBitMap::verify_clear() const 249 { 250 const idx_t* const beg = (const idx_t*)_virtual_space->committed_low_addr(); 251 const idx_t* const end = (const idx_t*)_virtual_space->committed_high_addr(); 252 for (const idx_t* p = beg; p < end; ++p) { 253 assert(*p == 0, "bitmap not clear"); 254 } 255 } 256 #endif // #ifdef ASSERT