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