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