Thu, 07 Aug 2014 22:28:53 +0200
8054341: Remove some obsolete code in G1CollectedHeap class
Summary: Remove dead code.
Reviewed-by: stefank, brutisso
1 /*
2 * Copyright (c) 2001, 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 */
25 #include "precompiled.hpp"
26 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
27 #include "gc_implementation/g1/heapRegion.hpp"
28 #include "gc_implementation/g1/satbQueue.hpp"
29 #include "runtime/mutexLocker.hpp"
30 #include "runtime/orderAccess.inline.hpp"
31 #include "runtime/thread.inline.hpp"
33 G1SATBCardTableModRefBS::G1SATBCardTableModRefBS(MemRegion whole_heap,
34 int max_covered_regions) :
35 CardTableModRefBSForCTRS(whole_heap, max_covered_regions)
36 {
37 _kind = G1SATBCT;
38 }
41 void G1SATBCardTableModRefBS::enqueue(oop pre_val) {
42 // Nulls should have been already filtered.
43 assert(pre_val->is_oop(true), "Error");
45 if (!JavaThread::satb_mark_queue_set().is_active()) return;
46 Thread* thr = Thread::current();
47 if (thr->is_Java_thread()) {
48 JavaThread* jt = (JavaThread*)thr;
49 jt->satb_mark_queue().enqueue(pre_val);
50 } else {
51 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag);
52 JavaThread::satb_mark_queue_set().shared_satb_queue()->enqueue(pre_val);
53 }
54 }
56 template <class T> void
57 G1SATBCardTableModRefBS::write_ref_array_pre_work(T* dst, int count) {
58 if (!JavaThread::satb_mark_queue_set().is_active()) return;
59 T* elem_ptr = dst;
60 for (int i = 0; i < count; i++, elem_ptr++) {
61 T heap_oop = oopDesc::load_heap_oop(elem_ptr);
62 if (!oopDesc::is_null(heap_oop)) {
63 enqueue(oopDesc::decode_heap_oop_not_null(heap_oop));
64 }
65 }
66 }
68 void G1SATBCardTableModRefBS::write_ref_array_pre(oop* dst, int count, bool dest_uninitialized) {
69 if (!dest_uninitialized) {
70 write_ref_array_pre_work(dst, count);
71 }
72 }
73 void G1SATBCardTableModRefBS::write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized) {
74 if (!dest_uninitialized) {
75 write_ref_array_pre_work(dst, count);
76 }
77 }
79 bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) {
80 jbyte val = _byte_map[card_index];
81 // It's already processed
82 if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) {
83 return false;
84 }
86 if (val == g1_young_gen) {
87 // the card is for a young gen region. We don't need to keep track of all pointers into young
88 return false;
89 }
91 // Cached bit can be installed either on a clean card or on a claimed card.
92 jbyte new_val = val;
93 if (val == clean_card_val()) {
94 new_val = (jbyte)deferred_card_val();
95 } else {
96 if (val & claimed_card_val()) {
97 new_val = val | (jbyte)deferred_card_val();
98 }
99 }
100 if (new_val != val) {
101 Atomic::cmpxchg(new_val, &_byte_map[card_index], val);
102 }
103 return true;
104 }
106 void G1SATBCardTableModRefBS::g1_mark_as_young(const MemRegion& mr) {
107 jbyte *const first = byte_for(mr.start());
108 jbyte *const last = byte_after(mr.last());
110 // Below we may use an explicit loop instead of memset() because on
111 // certain platforms memset() can give concurrent readers phantom zeros.
112 if (UseMemSetInBOT) {
113 memset(first, g1_young_gen, last - first);
114 } else {
115 for (jbyte* i = first; i < last; i++) {
116 *i = g1_young_gen;
117 }
118 }
119 }
121 #ifndef PRODUCT
122 void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) {
123 verify_region(mr, g1_young_gen, true);
124 }
125 #endif
127 G1SATBCardTableLoggingModRefBS::
128 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
129 int max_covered_regions) :
130 G1SATBCardTableModRefBS(whole_heap, max_covered_regions),
131 _dcqs(JavaThread::dirty_card_queue_set())
132 {
133 _kind = G1SATBCTLogging;
134 }
136 void
137 G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field,
138 oop new_val,
139 bool release) {
140 volatile jbyte* byte = byte_for(field);
141 if (*byte == g1_young_gen) {
142 return;
143 }
144 OrderAccess::storeload();
145 if (*byte != dirty_card) {
146 *byte = dirty_card;
147 Thread* thr = Thread::current();
148 if (thr->is_Java_thread()) {
149 JavaThread* jt = (JavaThread*)thr;
150 jt->dirty_card_queue().enqueue(byte);
151 } else {
152 MutexLockerEx x(Shared_DirtyCardQ_lock,
153 Mutex::_no_safepoint_check_flag);
154 _dcqs.shared_dirty_card_queue()->enqueue(byte);
155 }
156 }
157 }
159 void
160 G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field,
161 oop new_val) {
162 uintptr_t field_uint = (uintptr_t)field;
163 uintptr_t new_val_uint = cast_from_oop<uintptr_t>(new_val);
164 uintptr_t comb = field_uint ^ new_val_uint;
165 comb = comb >> HeapRegion::LogOfHRGrainBytes;
166 if (comb == 0) return;
167 if (new_val == NULL) return;
168 // Otherwise, log it.
169 G1SATBCardTableLoggingModRefBS* g1_bs =
170 (G1SATBCardTableLoggingModRefBS*)Universe::heap()->barrier_set();
171 g1_bs->write_ref_field_work(field, new_val);
172 }
174 void
175 G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
176 volatile jbyte* byte = byte_for(mr.start());
177 jbyte* last_byte = byte_for(mr.last());
178 Thread* thr = Thread::current();
179 if (whole_heap) {
180 while (byte <= last_byte) {
181 *byte = dirty_card;
182 byte++;
183 }
184 } else {
185 // skip all consecutive young cards
186 for (; byte <= last_byte && *byte == g1_young_gen; byte++);
188 if (byte <= last_byte) {
189 OrderAccess::storeload();
190 // Enqueue if necessary.
191 if (thr->is_Java_thread()) {
192 JavaThread* jt = (JavaThread*)thr;
193 for (; byte <= last_byte; byte++) {
194 if (*byte == g1_young_gen) {
195 continue;
196 }
197 if (*byte != dirty_card) {
198 *byte = dirty_card;
199 jt->dirty_card_queue().enqueue(byte);
200 }
201 }
202 } else {
203 MutexLockerEx x(Shared_DirtyCardQ_lock,
204 Mutex::_no_safepoint_check_flag);
205 for (; byte <= last_byte; byte++) {
206 if (*byte == g1_young_gen) {
207 continue;
208 }
209 if (*byte != dirty_card) {
210 *byte = dirty_card;
211 _dcqs.shared_dirty_card_queue()->enqueue(byte);
212 }
213 }
214 }
215 }
216 }
217 }