1 /*
  2  * Copyright (c) 2015, 2020, 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 #ifndef SHARE_GC_Z_ZLIVEMAP_INLINE_HPP
 25 #define SHARE_GC_Z_ZLIVEMAP_INLINE_HPP
 26 
 27 #include "gc/z/zLiveMap.hpp"
 28 
 29 #include "gc/z/zBitMap.inline.hpp"
 30 #include "gc/z/zMark.hpp"
 31 #include "gc/z/zOop.inline.hpp"
 32 #include "gc/z/zUtils.inline.hpp"
 33 #include "runtime/atomic.hpp"
 34 #include "utilities/bitMap.inline.hpp"
 35 #include "utilities/debug.hpp"
 36 
 37 inline void ZLiveMap::reset() {
 38   _seqnum = 0;
 39 }
 40 
 41 inline bool ZLiveMap::is_marked() const {
 42   return Atomic::load_acquire(&_seqnum) == ZGlobalSeqNum;
 43 }
 44 
 45 inline uint32_t ZLiveMap::live_objects() const {
 46   assert(ZGlobalPhase != ZPhaseMark, "Invalid phase");
 47   return _live_objects;
 48 }
 49 
 50 inline size_t ZLiveMap::live_bytes() const {
 51   assert(ZGlobalPhase != ZPhaseMark, "Invalid phase");
 52   return _live_bytes;
 53 }
 54 
 55 inline const BitMapView ZLiveMap::segment_live_bits() const {
 56   return BitMapView(const_cast<BitMap::bm_word_t*>(&_segment_live_bits), nsegments);
 57 }
 58 
 59 inline const BitMapView ZLiveMap::segment_claim_bits() const {
 60   return BitMapView(const_cast<BitMap::bm_word_t*>(&_segment_claim_bits), nsegments);
 61 }
 62 
 63 inline BitMapView ZLiveMap::segment_live_bits() {
 64   return BitMapView(&_segment_live_bits, nsegments);
 65 }
 66 
 67 inline BitMapView ZLiveMap::segment_claim_bits() {
 68   return BitMapView(&_segment_claim_bits, nsegments);
 69 }
 70 
 71 inline bool ZLiveMap::is_segment_live(BitMap::idx_t segment) const {
 72   return segment_live_bits().par_at(segment);
 73 }
 74 
 75 inline bool ZLiveMap::set_segment_live(BitMap::idx_t segment) {
 76   return segment_live_bits().par_set_bit(segment, memory_order_release);
 77 }
 78 
 79 inline bool ZLiveMap::claim_segment(BitMap::idx_t segment) {
 80   return segment_claim_bits().par_set_bit(segment, memory_order_acq_rel);
 81 }
 82 
 83 inline BitMap::idx_t ZLiveMap::first_live_segment() const {
 84   return segment_live_bits().get_next_one_offset(0, nsegments);
 85 }
 86 
 87 inline BitMap::idx_t ZLiveMap::next_live_segment(BitMap::idx_t segment) const {
 88   return segment_live_bits().get_next_one_offset(segment + 1, nsegments);
 89 }
 90 
 91 inline BitMap::idx_t ZLiveMap::segment_size() const {
 92   return _bitmap.size() / nsegments;
 93 }
 94 
 95 inline BitMap::idx_t ZLiveMap::index_to_segment(BitMap::idx_t index) const {
 96   return index >> _segment_shift;
 97 }
 98 
 99 inline bool ZLiveMap::get(size_t index) const {
100   BitMap::idx_t segment = index_to_segment(index);
101   return is_marked() &&                               // Page is marked
102          is_segment_live(segment) &&                  // Segment is marked
103          _bitmap.par_at(index, memory_order_relaxed); // Object is marked
104 }
105 
106 inline bool ZLiveMap::set(size_t index, bool finalizable, bool& inc_live) {
107   if (!is_marked()) {
108     // First object to be marked during this
109     // cycle, reset marking information.
110     reset(index);
111   }
112 
113   const BitMap::idx_t segment = index_to_segment(index);
114   if (!is_segment_live(segment)) {
115     // First object to be marked in this segment during
116     // this cycle, reset segment bitmap.
117     reset_segment(segment);
118   }
119 
120   return _bitmap.par_set_bit_pair(index, finalizable, inc_live);
121 }
122 
123 inline void ZLiveMap::inc_live(uint32_t objects, size_t bytes) {
124   Atomic::add(&_live_objects, objects);
125   Atomic::add(&_live_bytes, bytes);
126 }
127 
128 inline BitMap::idx_t ZLiveMap::segment_start(BitMap::idx_t segment) const {
129   return segment_size() * segment;
130 }
131 
132 inline BitMap::idx_t ZLiveMap::segment_end(BitMap::idx_t segment) const {
133   return segment_start(segment) + segment_size();
134 }
135 
136 inline void ZLiveMap::iterate_segment(ObjectClosure* cl, BitMap::idx_t segment, uintptr_t page_start, size_t page_object_alignment_shift) {
137   assert(is_segment_live(segment), "Must be");
138 
139   const BitMap::idx_t start_index = segment_start(segment);
140   const BitMap::idx_t end_index   = segment_end(segment);
141   BitMap::idx_t index = _bitmap.get_next_one_offset(start_index, end_index);
142 
143   while (index < end_index) {
144     // Calculate object address
145     const uintptr_t addr = page_start + ((index / 2) << page_object_alignment_shift);
146 
147     // Apply closure
148     cl->do_object(ZOop::from_address(addr));
149 
150     // Find next bit after this object
151     const uintptr_t next_addr = align_up(addr + 1, 1 << page_object_alignment_shift);
152     const BitMap::idx_t next_index = ((next_addr - page_start) >> page_object_alignment_shift) * 2;
153     if (next_index >= end_index) {
154       // End of live map
155       break;
156     }
157 
158     index = _bitmap.get_next_one_offset(next_index, end_index);
159   }
160 }
161 
162 inline void ZLiveMap::iterate(ObjectClosure* cl, uintptr_t page_start, size_t page_object_alignment_shift) {
163   if (is_marked()) {
164     for (BitMap::idx_t segment = first_live_segment(); segment < nsegments; segment = next_live_segment(segment)) {
165       // For each live segment
166       iterate_segment(cl, segment, page_start, page_object_alignment_shift);
167     }
168   }
169 }
170 
171 #endif // SHARE_GC_Z_ZLIVEMAP_INLINE_HPP