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/dirtyCardQueue.hpp"
27 #include "gc_implementation/g1/heapRegionRemSet.hpp"
28 #include "runtime/atomic.hpp"
29 #include "runtime/mutexLocker.hpp"
30 #include "runtime/safepoint.hpp"
31 #include "runtime/thread.inline.hpp"
32 #include "utilities/workgroup.hpp"
33
34 bool DirtyCardQueue::apply_closure(CardTableEntryClosure* cl,
35 bool consume,
36 size_t worker_i) {
37 bool res = true;
38 if (_buf != NULL) {
39 res = apply_closure_to_buffer(cl, _buf, _index, _sz,
40 consume,
41 (int) worker_i);
42 if (res && consume) _index = _sz;
43 }
44 return res;
45 }
46
47 bool DirtyCardQueue::apply_closure_to_buffer(CardTableEntryClosure* cl,
48 void** buf,
49 size_t index, size_t sz,
50 bool consume,
51 int worker_i) {
52 if (cl == NULL) return true;
53 for (size_t i = index; i < sz; i += oopSize) {
54 int ind = byte_index_to_index((int)i);
55 jbyte* card_ptr = (jbyte*)buf[ind];
56 if (card_ptr != NULL) {
57 // Set the entry to null, so we don't do it again (via the test
58 // above) if we reconsider this buffer.
59 if (consume) buf[ind] = NULL;
60 if (!cl->do_card_ptr(card_ptr, worker_i)) return false;
61 }
62 }
63 return true;
64 }
65
66 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
67 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
68 #endif // _MSC_VER
69
70 DirtyCardQueueSet::DirtyCardQueueSet(bool notify_when_complete) :
71 PtrQueueSet(notify_when_complete),
72 _closure(NULL),
73 _shared_dirty_card_queue(this, true /*perm*/),
74 _free_ids(NULL),
75 _processed_buffers_mut(0), _processed_buffers_rs_thread(0)
76 {
77 _all_active = true;
78 }
79
80 // Determines how many mutator threads can process the buffers in parallel.
81 size_t DirtyCardQueueSet::num_par_ids() {
82 return os::processor_count();
83 }
84
85 void DirtyCardQueueSet::initialize(Monitor* cbl_mon, Mutex* fl_lock,
86 int process_completed_threshold,
87 int max_completed_queue,
88 Mutex* lock, PtrQueueSet* fl_owner) {
89 PtrQueueSet::initialize(cbl_mon, fl_lock, process_completed_threshold,
90 max_completed_queue, fl_owner);
91 set_buffer_size(G1UpdateBufferSize);
92 _shared_dirty_card_queue.set_lock(lock);
93 _free_ids = new FreeIdSet((int) num_par_ids(), _cbl_mon);
94 }
95
96 void DirtyCardQueueSet::handle_zero_index_for_thread(JavaThread* t) {
97 t->dirty_card_queue().handle_zero_index();
98 }
99
100 void DirtyCardQueueSet::set_closure(CardTableEntryClosure* closure) {
101 _closure = closure;
102 }
103
104 void DirtyCardQueueSet::iterate_closure_all_threads(bool consume,
105 size_t worker_i) {
106 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
107 for(JavaThread* t = Threads::first(); t; t = t->next()) {
108 bool b = t->dirty_card_queue().apply_closure(_closure, consume);
109 guarantee(b, "Should not be interrupted.");
110 }
111 bool b = shared_dirty_card_queue()->apply_closure(_closure,
112 consume,
113 worker_i);
114 guarantee(b, "Should not be interrupted.");
115 }
116
117 bool DirtyCardQueueSet::mut_process_buffer(void** buf) {
118
119 // Used to determine if we had already claimed a par_id
120 // before entering this method.
121 bool already_claimed = false;
122
123 // We grab the current JavaThread.
124 JavaThread* thread = JavaThread::current();
125
126 // We get the the number of any par_id that this thread
127 // might have already claimed.
128 int worker_i = thread->get_claimed_par_id();
129
130 // If worker_i is not -1 then the thread has already claimed
131 // a par_id. We make note of it using the already_claimed value
132 if (worker_i != -1) {
133 already_claimed = true;
134 } else {
135
136 // Otherwise we need to claim a par id
137 worker_i = _free_ids->claim_par_id();
138
139 // And store the par_id value in the thread
140 thread->set_claimed_par_id(worker_i);
141 }
142
143 bool b = false;
144 if (worker_i != -1) {
145 b = DirtyCardQueue::apply_closure_to_buffer(_closure, buf, 0,
146 _sz, true, worker_i);
147 if (b) Atomic::inc(&_processed_buffers_mut);
148
149 // If we had not claimed an id before entering the method
150 // then we must release the id.
151 if (!already_claimed) {
152
153 // we release the id
154 _free_ids->release_par_id(worker_i);
155
156 // and set the claimed_id in the thread to -1
157 thread->set_claimed_par_id(-1);
158 }
159 }
160 return b;
161 }
162
163
164 BufferNode*
165 DirtyCardQueueSet::get_completed_buffer(int stop_at) {
166 BufferNode* nd = NULL;
167 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
168
169 if ((int)_n_completed_buffers <= stop_at) {
170 _process_completed = false;
171 return NULL;
172 }
173
174 if (_completed_buffers_head != NULL) {
175 nd = _completed_buffers_head;
176 _completed_buffers_head = nd->next();
177 if (_completed_buffers_head == NULL)
178 _completed_buffers_tail = NULL;
179 _n_completed_buffers--;
180 assert(_n_completed_buffers >= 0, "Invariant");
181 }
182 debug_only(assert_completed_buffer_list_len_correct_locked());
183 return nd;
184 }
185
186 bool DirtyCardQueueSet::
187 apply_closure_to_completed_buffer_helper(CardTableEntryClosure* cl,
188 int worker_i,
189 BufferNode* nd) {
190 if (nd != NULL) {
191 void **buf = BufferNode::make_buffer_from_node(nd);
192 size_t index = nd->index();
193 bool b =
194 DirtyCardQueue::apply_closure_to_buffer(cl, buf,
195 index, _sz,
196 true, worker_i);
197 if (b) {
198 deallocate_buffer(buf);
199 return true; // In normal case, go on to next buffer.
200 } else {
201 enqueue_complete_buffer(buf, index);
202 return false;
203 }
204 } else {
205 return false;
206 }
207 }
208
209 bool DirtyCardQueueSet::apply_closure_to_completed_buffer(CardTableEntryClosure* cl,
210 int worker_i,
211 int stop_at,
212 bool during_pause) {
213 assert(!during_pause || stop_at == 0, "Should not leave any completed buffers during a pause");
214 BufferNode* nd = get_completed_buffer(stop_at);
215 bool res = apply_closure_to_completed_buffer_helper(cl, worker_i, nd);
216 if (res) Atomic::inc(&_processed_buffers_rs_thread);
217 return res;
218 }
219
220 bool DirtyCardQueueSet::apply_closure_to_completed_buffer(int worker_i,
221 int stop_at,
222 bool during_pause) {
223 return apply_closure_to_completed_buffer(_closure, worker_i,
224 stop_at, during_pause);
225 }
226
227 void DirtyCardQueueSet::apply_closure_to_all_completed_buffers() {
228 BufferNode* nd = _completed_buffers_head;
229 while (nd != NULL) {
230 bool b =
231 DirtyCardQueue::apply_closure_to_buffer(_closure,
232 BufferNode::make_buffer_from_node(nd),
233 0, _sz, false);
234 guarantee(b, "Should not stop early.");
235 nd = nd->next();
236 }
237 }
238
239 // Deallocates any completed log buffers
240 void DirtyCardQueueSet::clear() {
241 BufferNode* buffers_to_delete = NULL;
242 {
243 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
244 while (_completed_buffers_head != NULL) {
245 BufferNode* nd = _completed_buffers_head;
246 _completed_buffers_head = nd->next();
247 nd->set_next(buffers_to_delete);
248 buffers_to_delete = nd;
249 }
250 _n_completed_buffers = 0;
251 _completed_buffers_tail = NULL;
252 debug_only(assert_completed_buffer_list_len_correct_locked());
253 }
254 while (buffers_to_delete != NULL) {
255 BufferNode* nd = buffers_to_delete;
256 buffers_to_delete = nd->next();
257 deallocate_buffer(BufferNode::make_buffer_from_node(nd));
258 }
259
260 }
261
262 void DirtyCardQueueSet::abandon_logs() {
263 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
264 clear();
265 // Since abandon is done only at safepoints, we can safely manipulate
266 // these queues.
267 for (JavaThread* t = Threads::first(); t; t = t->next()) {
268 t->dirty_card_queue().reset();
269 }
270 shared_dirty_card_queue()->reset();
271 }
272
273
274 void DirtyCardQueueSet::concatenate_logs() {
275 // Iterate over all the threads, if we find a partial log add it to
276 // the global list of logs. Temporarily turn off the limit on the number
277 // of outstanding buffers.
278 int save_max_completed_queue = _max_completed_queue;
279 _max_completed_queue = max_jint;
280 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
281 for (JavaThread* t = Threads::first(); t; t = t->next()) {
282 DirtyCardQueue& dcq = t->dirty_card_queue();
283 if (dcq.size() != 0) {
284 void **buf = t->dirty_card_queue().get_buf();
285 // We must NULL out the unused entries, then enqueue.
286 for (size_t i = 0; i < t->dirty_card_queue().get_index(); i += oopSize) {
287 buf[PtrQueue::byte_index_to_index((int)i)] = NULL;
288 }
289 enqueue_complete_buffer(dcq.get_buf(), dcq.get_index());
290 dcq.reinitialize();
291 }
292 }
293 if (_shared_dirty_card_queue.size() != 0) {
294 enqueue_complete_buffer(_shared_dirty_card_queue.get_buf(),
295 _shared_dirty_card_queue.get_index());
296 _shared_dirty_card_queue.reinitialize();
297 }
298 // Restore the completed buffer queue limit.
299 _max_completed_queue = save_max_completed_queue;
300 }