1 /*
2 * Copyright (c) 2005, 2012, 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_bsd
42 # include "os_bsd.inline.hpp"
43 #endif
44
45 bool
46 ParMarkBitMap::initialize(MemRegion covered_region)
47 {
48 const idx_t bits = bits_required(covered_region);
49 // The bits will be divided evenly between two bitmaps; each of them should be
50 // an integral number of words.
51 assert(bits % (BitsPerWord * 2) == 0, "region size unaligned");
52
53 const size_t words = bits / BitsPerWord;
54 const size_t raw_bytes = words * sizeof(idx_t);
55 const size_t page_sz = os::page_size_for_region(raw_bytes, raw_bytes, 10);
56 const size_t granularity = os::vm_allocation_granularity();
57 const size_t bytes = align_size_up(raw_bytes, MAX2(page_sz, granularity));
58
59 const size_t rs_align = page_sz == (size_t) os::vm_page_size() ? 0 :
60 MAX2(page_sz, granularity);
61 ReservedSpace rs(bytes, rs_align, rs_align > 0);
62 os::trace_page_sizes("par bitmap", raw_bytes, raw_bytes, page_sz,
63 rs.base(), rs.size());
64
65 MemTracker::record_virtual_memory_type((address)rs.base(), mtGC);
66
67 _virtual_space = new PSVirtualSpace(rs, page_sz);
68 if (_virtual_space != NULL && _virtual_space->expand_by(bytes)) {
69 _region_start = covered_region.start();
70 _region_size = covered_region.word_size();
71 idx_t* map = (idx_t*)_virtual_space->reserved_low_addr();
72 _beg_bits.set_map(map);
73 _beg_bits.set_size(bits / 2);
74 _end_bits.set_map(map + words / 2);
75 _end_bits.set_size(bits / 2);
76 return true;
77 }
78
79 _region_start = 0;
80 _region_size = 0;
81 if (_virtual_space != NULL) {
82 delete _virtual_space;
83 _virtual_space = NULL;
84 // Release memory reserved in the space.
85 rs.release();
86 }
87 return false;
88 }
89
90 #ifdef ASSERT
91 extern size_t mark_bitmap_count;
92 extern size_t mark_bitmap_size;
93 #endif // #ifdef ASSERT
94
95 bool
96 ParMarkBitMap::mark_obj(HeapWord* addr, size_t size)
97 {
98 const idx_t beg_bit = addr_to_bit(addr);
99 if (_beg_bits.par_set_bit(beg_bit)) {
100 const idx_t end_bit = addr_to_bit(addr + size - 1);
101 bool end_bit_ok = _end_bits.par_set_bit(end_bit);
102 assert(end_bit_ok, "concurrency problem");
103 DEBUG_ONLY(Atomic::inc_ptr(&mark_bitmap_count));
104 DEBUG_ONLY(Atomic::add_ptr(size, &mark_bitmap_size));
105 return true;
106 }
107 return false;
108 }
109
110 size_t ParMarkBitMap::live_words_in_range(HeapWord* beg_addr, oop end_obj) const
111 {
112 assert(beg_addr <= (HeapWord*)end_obj, "bad range");
113 assert(is_marked(end_obj), "end_obj must be live");
114
115 idx_t live_bits = 0;
116
117 // The bitmap routines require the right boundary to be word-aligned.
118 const idx_t end_bit = addr_to_bit((HeapWord*)end_obj);
119 const idx_t range_end = BitMap::word_align_up(end_bit);
120
121 idx_t beg_bit = find_obj_beg(addr_to_bit(beg_addr), range_end);
122 while (beg_bit < end_bit) {
123 idx_t tmp_end = find_obj_end(beg_bit, range_end);
124 assert(tmp_end < end_bit, "missing end bit");
125 live_bits += tmp_end - beg_bit + 1;
126 beg_bit = find_obj_beg(tmp_end + 1, range_end);
127 }
128 return bits_to_words(live_bits);
129 }
130
131 ParMarkBitMap::IterationStatus
132 ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure,
133 idx_t range_beg, idx_t range_end) const
134 {
135 DEBUG_ONLY(verify_bit(range_beg);)
136 DEBUG_ONLY(verify_bit(range_end);)
137 assert(range_beg <= range_end, "live range invalid");
138
139 // The bitmap routines require the right boundary to be word-aligned.
140 const idx_t search_end = BitMap::word_align_up(range_end);
141
142 idx_t cur_beg = find_obj_beg(range_beg, search_end);
143 while (cur_beg < range_end) {
144 const idx_t cur_end = find_obj_end(cur_beg, search_end);
145 if (cur_end >= range_end) {
146 // The obj ends outside the range.
147 live_closure->set_source(bit_to_addr(cur_beg));
148 return incomplete;
149 }
150
151 const size_t size = obj_size(cur_beg, cur_end);
152 IterationStatus status = live_closure->do_addr(bit_to_addr(cur_beg), size);
153 if (status != incomplete) {
154 assert(status == would_overflow || status == full, "sanity");
155 return status;
156 }
157
158 // Successfully processed the object; look for the next object.
159 cur_beg = find_obj_beg(cur_end + 1, search_end);
160 }
161
162 live_closure->set_source(bit_to_addr(range_end));
163 return complete;
164 }
165
166 ParMarkBitMap::IterationStatus
167 ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure,
168 ParMarkBitMapClosure* dead_closure,
169 idx_t range_beg, idx_t range_end,
170 idx_t dead_range_end) const
171 {
172 DEBUG_ONLY(verify_bit(range_beg);)
173 DEBUG_ONLY(verify_bit(range_end);)
174 DEBUG_ONLY(verify_bit(dead_range_end);)
175 assert(range_beg <= range_end, "live range invalid");
176 assert(range_end <= dead_range_end, "dead range invalid");
177
178 // The bitmap routines require the right boundary to be word-aligned.
179 const idx_t live_search_end = BitMap::word_align_up(range_end);
180 const idx_t dead_search_end = BitMap::word_align_up(dead_range_end);
181
182 idx_t cur_beg = range_beg;
183 if (range_beg < range_end && is_unmarked(range_beg)) {
184 // The range starts with dead space. Look for the next object, then fill.
185 cur_beg = find_obj_beg(range_beg + 1, dead_search_end);
186 const idx_t dead_space_end = MIN2(cur_beg - 1, dead_range_end - 1);
187 const size_t size = obj_size(range_beg, dead_space_end);
188 dead_closure->do_addr(bit_to_addr(range_beg), size);
189 }
190
191 while (cur_beg < range_end) {
192 const idx_t cur_end = find_obj_end(cur_beg, live_search_end);
193 if (cur_end >= range_end) {
194 // The obj ends outside the range.
195 live_closure->set_source(bit_to_addr(cur_beg));
196 return incomplete;
197 }
198
199 const size_t size = obj_size(cur_beg, cur_end);
200 IterationStatus status = live_closure->do_addr(bit_to_addr(cur_beg), size);
201 if (status != incomplete) {
202 assert(status == would_overflow || status == full, "sanity");
203 return status;
204 }
205
206 // Look for the start of the next object.
207 const idx_t dead_space_beg = cur_end + 1;
208 cur_beg = find_obj_beg(dead_space_beg, dead_search_end);
209 if (cur_beg > dead_space_beg) {
210 // Found dead space; compute the size and invoke the dead closure.
211 const idx_t dead_space_end = MIN2(cur_beg - 1, dead_range_end - 1);
212 const size_t size = obj_size(dead_space_beg, dead_space_end);
213 dead_closure->do_addr(bit_to_addr(dead_space_beg), size);
214 }
215 }
216
217 live_closure->set_source(bit_to_addr(range_end));
218 return complete;
219 }
220
221 #ifdef ASSERT
222 void ParMarkBitMap::verify_clear() const
223 {
224 const idx_t* const beg = (const idx_t*)_virtual_space->committed_low_addr();
225 const idx_t* const end = (const idx_t*)_virtual_space->committed_high_addr();
226 for (const idx_t* p = beg; p < end; ++p) {
227 assert(*p == 0, "bitmap not clear");
228 }
229 }
230 #endif // #ifdef ASSERT