1 /*
2 * Copyright (c) 2001, 2010, 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/g1/satbQueue.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "memory/sharedHeap.hpp"
29 #include "runtime/mutexLocker.hpp"
30 #include "runtime/thread.hpp"
31
32 void ObjPtrQueue::apply_closure(ObjectClosure* cl) {
33 if (_buf != NULL) {
34 apply_closure_to_buffer(cl, _buf, _index, _sz);
35 _index = _sz;
36 }
37 }
38
39 void ObjPtrQueue::apply_closure_to_buffer(ObjectClosure* cl,
40 void** buf, size_t index, size_t sz) {
41 if (cl == NULL) return;
42 for (size_t i = index; i < sz; i += oopSize) {
43 oop obj = (oop)buf[byte_index_to_index((int)i)];
44 // There can be NULL entries because of destructors.
45 if (obj != NULL) {
46 cl->do_object(obj);
47 }
48 }
49 }
50
51 #ifdef ASSERT
52 void ObjPtrQueue::verify_oops_in_buffer() {
53 if (_buf == NULL) return;
54 for (size_t i = _index; i < _sz; i += oopSize) {
55 oop obj = (oop)_buf[byte_index_to_index((int)i)];
56 assert(obj != NULL && obj->is_oop(true /* ignore mark word */),
57 "Not an oop");
58 }
59 }
60 #endif
61
62 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
63 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
64 #endif // _MSC_VER
65
66
67 SATBMarkQueueSet::SATBMarkQueueSet() :
68 PtrQueueSet(),
69 _closure(NULL), _par_closures(NULL),
70 _shared_satb_queue(this, true /*perm*/)
71 {}
72
73 void SATBMarkQueueSet::initialize(Monitor* cbl_mon, Mutex* fl_lock,
74 int process_completed_threshold,
75 Mutex* lock) {
76 PtrQueueSet::initialize(cbl_mon, fl_lock, process_completed_threshold, -1);
77 _shared_satb_queue.set_lock(lock);
78 if (ParallelGCThreads > 0) {
79 _par_closures = NEW_C_HEAP_ARRAY(ObjectClosure*, ParallelGCThreads);
80 }
81 }
82
83
84 void SATBMarkQueueSet::handle_zero_index_for_thread(JavaThread* t) {
85 DEBUG_ONLY(t->satb_mark_queue().verify_oops_in_buffer();)
86 t->satb_mark_queue().handle_zero_index();
87 }
88
89 #ifdef ASSERT
90 void SATBMarkQueueSet::dump_active_values(JavaThread* first,
91 bool expected_active) {
92 gclog_or_tty->print_cr("SATB queue active values for Java Threads");
93 gclog_or_tty->print_cr(" SATB queue set: active is %s",
94 (is_active()) ? "TRUE" : "FALSE");
95 gclog_or_tty->print_cr(" expected_active is %s",
96 (expected_active) ? "TRUE" : "FALSE");
97 for (JavaThread* t = first; t; t = t->next()) {
98 bool active = t->satb_mark_queue().is_active();
99 gclog_or_tty->print_cr(" thread %s, active is %s",
100 t->name(), (active) ? "TRUE" : "FALSE");
101 }
102 }
103 #endif // ASSERT
104
105 void SATBMarkQueueSet::set_active_all_threads(bool b,
106 bool expected_active) {
107 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
108 JavaThread* first = Threads::first();
109
110 #ifdef ASSERT
111 if (_all_active != expected_active) {
112 dump_active_values(first, expected_active);
113
114 // I leave this here as a guarantee, instead of an assert, so
115 // that it will still be compiled in if we choose to uncomment
116 // the #ifdef ASSERT in a product build. The whole block is
117 // within an #ifdef ASSERT so the guarantee will not be compiled
118 // in a product build anyway.
119 guarantee(false,
120 "SATB queue set has an unexpected active value");
121 }
122 #endif // ASSERT
123 _all_active = b;
124
125 for (JavaThread* t = first; t; t = t->next()) {
126 #ifdef ASSERT
127 bool active = t->satb_mark_queue().is_active();
128 if (active != expected_active) {
129 dump_active_values(first, expected_active);
130
131 // I leave this here as a guarantee, instead of an assert, so
132 // that it will still be compiled in if we choose to uncomment
133 // the #ifdef ASSERT in a product build. The whole block is
134 // within an #ifdef ASSERT so the guarantee will not be compiled
135 // in a product build anyway.
136 guarantee(false,
137 "thread has an unexpected active value in its SATB queue");
138 }
139 #endif // ASSERT
140 t->satb_mark_queue().set_active(b);
141 }
142 }
143
144 void SATBMarkQueueSet::set_closure(ObjectClosure* closure) {
145 _closure = closure;
146 }
147
148 void SATBMarkQueueSet::set_par_closure(int i, ObjectClosure* par_closure) {
149 assert(ParallelGCThreads > 0 && _par_closures != NULL, "Precondition");
150 _par_closures[i] = par_closure;
151 }
152
153 void SATBMarkQueueSet::iterate_closure_all_threads() {
154 for(JavaThread* t = Threads::first(); t; t = t->next()) {
155 t->satb_mark_queue().apply_closure(_closure);
156 }
157 shared_satb_queue()->apply_closure(_closure);
158 }
159
160 void SATBMarkQueueSet::par_iterate_closure_all_threads(int worker) {
161 SharedHeap* sh = SharedHeap::heap();
162 int parity = sh->strong_roots_parity();
163
164 for(JavaThread* t = Threads::first(); t; t = t->next()) {
165 if (t->claim_oops_do(true, parity)) {
166 t->satb_mark_queue().apply_closure(_par_closures[worker]);
167 }
168 }
169 // We'll have worker 0 do this one.
170 if (worker == 0) {
171 shared_satb_queue()->apply_closure(_par_closures[0]);
172 }
173 }
174
175 bool SATBMarkQueueSet::apply_closure_to_completed_buffer_work(bool par,
176 int worker) {
177 BufferNode* nd = NULL;
178 {
179 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
180 if (_completed_buffers_head != NULL) {
181 nd = _completed_buffers_head;
182 _completed_buffers_head = nd->next();
183 if (_completed_buffers_head == NULL) _completed_buffers_tail = NULL;
184 _n_completed_buffers--;
185 if (_n_completed_buffers == 0) _process_completed = false;
186 }
187 }
188 ObjectClosure* cl = (par ? _par_closures[worker] : _closure);
189 if (nd != NULL) {
190 void **buf = BufferNode::make_buffer_from_node(nd);
191 ObjPtrQueue::apply_closure_to_buffer(cl, buf, 0, _sz);
192 deallocate_buffer(buf);
193 return true;
194 } else {
195 return false;
196 }
197 }
198
199 void SATBMarkQueueSet::abandon_partial_marking() {
200 BufferNode* buffers_to_delete = NULL;
201 {
202 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
203 while (_completed_buffers_head != NULL) {
204 BufferNode* nd = _completed_buffers_head;
205 _completed_buffers_head = nd->next();
206 nd->set_next(buffers_to_delete);
207 buffers_to_delete = nd;
208 }
209 _completed_buffers_tail = NULL;
210 _n_completed_buffers = 0;
211 DEBUG_ONLY(assert_completed_buffer_list_len_correct_locked());
212 }
213 while (buffers_to_delete != NULL) {
214 BufferNode* nd = buffers_to_delete;
215 buffers_to_delete = nd->next();
216 deallocate_buffer(BufferNode::make_buffer_from_node(nd));
217 }
218 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
219 // So we can safely manipulate these queues.
220 for (JavaThread* t = Threads::first(); t; t = t->next()) {
221 t->satb_mark_queue().reset();
222 }
223 shared_satb_queue()->reset();
224 }