1 /*
   2  * Copyright (c) 2005, 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.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "gc_implementation/parallelScavenge/parMarkBitMap.hpp"
  27 #include "gc_implementation/parallelScavenge/psParallelCompact.hpp"
  28 #include "oops/oop.inline.hpp"
  29 #include "runtime/os.hpp"
  30 #include "utilities/bitMap.inline.hpp"
  31 #include "services/memTracker.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 #ifdef TARGET_OS_FAMILY_aix
  42 # include "os_aix.inline.hpp"
  43 #endif
  44 #ifdef TARGET_OS_FAMILY_bsd
  45 # include "os_bsd.inline.hpp"
  46 #endif
  47 
  48 bool
  49 ParMarkBitMap::initialize(MemRegion covered_region)
  50 {
  51   const idx_t bits = bits_required(covered_region);
  52   // The bits will be divided evenly between two bitmaps; each of them should be
  53   // an integral number of words.
  54   assert(bits % (BitsPerWord * 2) == 0, "region size unaligned");
  55 
  56   const size_t words = bits / BitsPerWord;
  57   const size_t raw_bytes = words * sizeof(idx_t);
  58   const size_t page_sz = os::page_size_for_region(raw_bytes, raw_bytes, 10);
  59   const size_t granularity = os::vm_allocation_granularity();
  60   _reserved_byte_size = align_size_up(raw_bytes, MAX2(page_sz, granularity));
  61 
  62   const size_t rs_align = page_sz == (size_t) os::vm_page_size() ? 0 :
  63     MAX2(page_sz, granularity);
  64   ReservedSpace rs(_reserved_byte_size, rs_align, rs_align > 0);
  65   os::trace_page_sizes("par bitmap", raw_bytes, raw_bytes, page_sz,
  66                        rs.base(), rs.size());
  67 
  68   MemTracker::record_virtual_memory_type((address)rs.base(), mtGC);
  69 
  70   _virtual_space = new PSVirtualSpace(rs, page_sz);
  71   if (_virtual_space != NULL && _virtual_space->expand_by(_reserved_byte_size)) {
  72     _region_start = covered_region.start();
  73     _region_size = covered_region.word_size();
  74     BitMap::bm_word_t* map = (BitMap::bm_word_t*)_virtual_space->reserved_low_addr();
  75     _beg_bits.set_map(map);
  76     _beg_bits.set_size(bits / 2);
  77     _end_bits.set_map(map + words / 2);
  78     _end_bits.set_size(bits / 2);
  79     return true;
  80   }
  81 
  82   _region_start = 0;
  83   _region_size = 0;
  84   if (_virtual_space != NULL) {
  85     delete _virtual_space;
  86     _virtual_space = NULL;
  87     // Release memory reserved in the space.
  88     rs.release();
  89   }
  90   return false;
  91 }
  92 
  93 #ifdef ASSERT
  94 extern size_t mark_bitmap_count;
  95 extern size_t mark_bitmap_size;
  96 #endif  // #ifdef ASSERT
  97 
  98 bool
  99 ParMarkBitMap::mark_obj(HeapWord* addr, size_t size)
 100 {
 101   const idx_t beg_bit = addr_to_bit(addr);
 102   if (_beg_bits.par_set_bit(beg_bit)) {
 103     const idx_t end_bit = addr_to_bit(addr + size - 1);
 104     bool end_bit_ok = _end_bits.par_set_bit(end_bit);
 105     assert(end_bit_ok, "concurrency problem");
 106     DEBUG_ONLY(Atomic::inc_ptr(&mark_bitmap_count));
 107     DEBUG_ONLY(Atomic::add_ptr(size, &mark_bitmap_size));
 108     return true;
 109   }
 110   return false;
 111 }
 112 
 113 size_t ParMarkBitMap::live_words_in_range(HeapWord* beg_addr, oop end_obj) const
 114 {
 115   assert(beg_addr <= (HeapWord*)end_obj, "bad range");
 116   assert(is_marked(end_obj), "end_obj must be live");
 117 
 118   idx_t live_bits = 0;
 119 
 120   // The bitmap routines require the right boundary to be word-aligned.
 121   const idx_t end_bit = addr_to_bit((HeapWord*)end_obj);
 122   const idx_t range_end = BitMap::word_align_up(end_bit);
 123 
 124   idx_t beg_bit = find_obj_beg(addr_to_bit(beg_addr), range_end);
 125   while (beg_bit < end_bit) {
 126     idx_t tmp_end = find_obj_end(beg_bit, range_end);
 127     assert(tmp_end < end_bit, "missing end bit");
 128     live_bits += tmp_end - beg_bit + 1;
 129     beg_bit = find_obj_beg(tmp_end + 1, range_end);
 130   }
 131   return bits_to_words(live_bits);
 132 }
 133 
 134 ParMarkBitMap::IterationStatus
 135 ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure,
 136                        idx_t range_beg, idx_t range_end) const
 137 {
 138   DEBUG_ONLY(verify_bit(range_beg);)
 139   DEBUG_ONLY(verify_bit(range_end);)
 140   assert(range_beg <= range_end, "live range invalid");
 141 
 142   // The bitmap routines require the right boundary to be word-aligned.
 143   const idx_t search_end = BitMap::word_align_up(range_end);
 144 
 145   idx_t cur_beg = find_obj_beg(range_beg, search_end);
 146   while (cur_beg < range_end) {
 147     const idx_t cur_end = find_obj_end(cur_beg, search_end);
 148     if (cur_end >= range_end) {
 149       // The obj ends outside the range.
 150       live_closure->set_source(bit_to_addr(cur_beg));
 151       return incomplete;
 152     }
 153 
 154     const size_t size = obj_size(cur_beg, cur_end);
 155     IterationStatus status = live_closure->do_addr(bit_to_addr(cur_beg), size);
 156     if (status != incomplete) {
 157       assert(status == would_overflow || status == full, "sanity");
 158       return status;
 159     }
 160 
 161     // Successfully processed the object; look for the next object.
 162     cur_beg = find_obj_beg(cur_end + 1, search_end);
 163   }
 164 
 165   live_closure->set_source(bit_to_addr(range_end));
 166   return complete;
 167 }
 168 
 169 ParMarkBitMap::IterationStatus
 170 ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure,
 171                        ParMarkBitMapClosure* dead_closure,
 172                        idx_t range_beg, idx_t range_end,
 173                        idx_t dead_range_end) const
 174 {
 175   DEBUG_ONLY(verify_bit(range_beg);)
 176   DEBUG_ONLY(verify_bit(range_end);)
 177   DEBUG_ONLY(verify_bit(dead_range_end);)
 178   assert(range_beg <= range_end, "live range invalid");
 179   assert(range_end <= dead_range_end, "dead range invalid");
 180 
 181   // The bitmap routines require the right boundary to be word-aligned.
 182   const idx_t live_search_end = BitMap::word_align_up(range_end);
 183   const idx_t dead_search_end = BitMap::word_align_up(dead_range_end);
 184 
 185   idx_t cur_beg = range_beg;
 186   if (range_beg < range_end && is_unmarked(range_beg)) {
 187     // The range starts with dead space.  Look for the next object, then fill.
 188     cur_beg = find_obj_beg(range_beg + 1, dead_search_end);
 189     const idx_t dead_space_end = MIN2(cur_beg - 1, dead_range_end - 1);
 190     const size_t size = obj_size(range_beg, dead_space_end);
 191     dead_closure->do_addr(bit_to_addr(range_beg), size);
 192   }
 193 
 194   while (cur_beg < range_end) {
 195     const idx_t cur_end = find_obj_end(cur_beg, live_search_end);
 196     if (cur_end >= range_end) {
 197       // The obj ends outside the range.
 198       live_closure->set_source(bit_to_addr(cur_beg));
 199       return incomplete;
 200     }
 201 
 202     const size_t size = obj_size(cur_beg, cur_end);
 203     IterationStatus status = live_closure->do_addr(bit_to_addr(cur_beg), size);
 204     if (status != incomplete) {
 205       assert(status == would_overflow || status == full, "sanity");
 206       return status;
 207     }
 208 
 209     // Look for the start of the next object.
 210     const idx_t dead_space_beg = cur_end + 1;
 211     cur_beg = find_obj_beg(dead_space_beg, dead_search_end);
 212     if (cur_beg > dead_space_beg) {
 213       // Found dead space; compute the size and invoke the dead closure.
 214       const idx_t dead_space_end = MIN2(cur_beg - 1, dead_range_end - 1);
 215       const size_t size = obj_size(dead_space_beg, dead_space_end);
 216       dead_closure->do_addr(bit_to_addr(dead_space_beg), size);
 217     }
 218   }
 219 
 220   live_closure->set_source(bit_to_addr(range_end));
 221   return complete;
 222 }
 223 
 224 #ifdef ASSERT
 225 void ParMarkBitMap::verify_clear() const
 226 {
 227   const idx_t* const beg = (const idx_t*)_virtual_space->committed_low_addr();
 228   const idx_t* const end = (const idx_t*)_virtual_space->committed_high_addr();
 229   for (const idx_t* p = beg; p < end; ++p) {
 230     assert(*p == 0, "bitmap not clear");
 231   }
 232 }
 233 #endif  // #ifdef ASSERT