1 /*
2 * Copyright (c) 2001, 2015, 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/g1/dirtyCardQueue.hpp"
27 #include "gc/g1/g1CollectedHeap.inline.hpp"
28 #include "gc/g1/heapRegionRemSet.hpp"
29 #include "gc/shared/workgroup.hpp"
30 #include "runtime/atomic.inline.hpp"
31 #include "runtime/mutexLocker.hpp"
32 #include "runtime/safepoint.hpp"
33 #include "runtime/thread.inline.hpp"
34
35 DirtyCardQueue::DirtyCardQueue(DirtyCardQueueSet* qset, bool permanent) :
36 // Dirty card queues are always active, so we create them with their
37 // active field set to true.
38 PtrQueue(qset, permanent, true /* active */)
39 { }
40
41 DirtyCardQueue::~DirtyCardQueue() {
42 if (!is_permanent()) {
43 flush();
44 }
45 }
46
47 bool DirtyCardQueue::apply_closure(CardTableEntryClosure* cl,
48 bool consume,
49 uint worker_i) {
50 bool res = true;
51 if (_buf != NULL) {
52 res = apply_closure_to_buffer(cl, _buf, _index, _sz,
53 consume,
54 worker_i);
55 if (res && consume) {
56 _index = _sz;
57 }
58 }
59 return res;
60 }
61
62 bool DirtyCardQueue::apply_closure_to_buffer(CardTableEntryClosure* cl,
63 void** buf,
64 size_t index, size_t sz,
65 bool consume,
66 uint worker_i) {
67 if (cl == NULL) return true;
68 size_t limit = byte_index_to_index(sz);
69 for (size_t i = byte_index_to_index(index); i < limit; ++i) {
70 jbyte* card_ptr = static_cast<jbyte*>(buf[i]);
71 if (card_ptr != NULL) {
72 // Set the entry to null, so we don't do it again (via the test
73 // above) if we reconsider this buffer.
74 if (consume) {
75 buf[i] = NULL;
76 }
77 if (!cl->do_card_ptr(card_ptr, worker_i)) {
78 return false;
79 }
80 }
81 }
82 return true;
83 }
84
85 DirtyCardQueueSet::DirtyCardQueueSet(bool notify_when_complete) :
86 PtrQueueSet(notify_when_complete),
87 _mut_process_closure(NULL),
88 _shared_dirty_card_queue(this, true /* permanent */),
89 _free_ids(NULL),
90 _processed_buffers_mut(0), _processed_buffers_rs_thread(0)
91 {
92 _all_active = true;
93 }
94
95 // Determines how many mutator threads can process the buffers in parallel.
96 uint DirtyCardQueueSet::num_par_ids() {
97 return (uint)os::processor_count();
98 }
99
100 void DirtyCardQueueSet::initialize(CardTableEntryClosure* cl,
101 Monitor* cbl_mon,
102 Mutex* fl_lock,
103 int process_completed_threshold,
104 int max_completed_queue,
105 Mutex* lock,
106 DirtyCardQueueSet* fl_owner) {
107 _mut_process_closure = cl;
108 PtrQueueSet::initialize(cbl_mon,
109 fl_lock,
110 process_completed_threshold,
111 max_completed_queue,
112 fl_owner);
113 set_buffer_size(G1UpdateBufferSize);
114 _shared_dirty_card_queue.set_lock(lock);
115 _free_ids = new FreeIdSet(num_par_ids(), _cbl_mon);
116 }
117
118 void DirtyCardQueueSet::handle_zero_index_for_thread(JavaThread* t) {
119 t->dirty_card_queue().handle_zero_index();
120 }
121
122 void DirtyCardQueueSet::iterate_closure_all_threads(CardTableEntryClosure* cl,
123 bool consume,
124 uint worker_i) {
125 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
126 for (JavaThread* t = Threads::first(); t; t = t->next()) {
127 bool b = t->dirty_card_queue().apply_closure(cl, consume);
128 guarantee(b, "Should not be interrupted.");
129 }
130 bool b = shared_dirty_card_queue()->apply_closure(cl,
131 consume,
132 worker_i);
133 guarantee(b, "Should not be interrupted.");
134 }
135
136 bool DirtyCardQueueSet::mut_process_buffer(void** buf) {
137
138 // Used to determine if we had already claimed a par_id
139 // before entering this method.
140 bool already_claimed = false;
141
142 // We grab the current JavaThread.
143 JavaThread* thread = JavaThread::current();
144
145 // We get the the number of any par_id that this thread
146 // might have already claimed.
147 uint worker_i = thread->get_claimed_par_id();
148
149 // If worker_i is not UINT_MAX then the thread has already claimed
150 // a par_id. We make note of it using the already_claimed value
151 if (worker_i != UINT_MAX) {
152 already_claimed = true;
153 } else {
154
155 // Otherwise we need to claim a par id
156 worker_i = _free_ids->claim_par_id();
157
158 // And store the par_id value in the thread
159 thread->set_claimed_par_id(worker_i);
160 }
161
162 bool b = false;
163 if (worker_i != UINT_MAX) {
164 b = DirtyCardQueue::apply_closure_to_buffer(_mut_process_closure, buf, 0,
165 _sz, true, worker_i);
166 if (b) Atomic::inc(&_processed_buffers_mut);
167
168 // If we had not claimed an id before entering the method
169 // then we must release the id.
170 if (!already_claimed) {
171
172 // we release the id
173 _free_ids->release_par_id(worker_i);
174
175 // and set the claimed_id in the thread to UINT_MAX
176 thread->set_claimed_par_id(UINT_MAX);
177 }
178 }
179 return b;
180 }
181
182
183 BufferNode* DirtyCardQueueSet::get_completed_buffer(int stop_at) {
184 BufferNode* nd = NULL;
185 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
186
187 if ((int)_n_completed_buffers <= stop_at) {
188 _process_completed = false;
189 return NULL;
190 }
191
192 if (_completed_buffers_head != NULL) {
193 nd = _completed_buffers_head;
194 _completed_buffers_head = nd->next();
195 if (_completed_buffers_head == NULL)
196 _completed_buffers_tail = NULL;
197 _n_completed_buffers--;
198 assert(_n_completed_buffers >= 0, "Invariant");
199 }
200 DEBUG_ONLY(assert_completed_buffer_list_len_correct_locked());
201 return nd;
202 }
203
204 bool DirtyCardQueueSet::apply_closure_to_completed_buffer_helper(CardTableEntryClosure* cl,
205 uint worker_i,
206 BufferNode* nd) {
207 if (nd != NULL) {
208 void **buf = BufferNode::make_buffer_from_node(nd);
209 size_t index = nd->index();
210 bool b =
211 DirtyCardQueue::apply_closure_to_buffer(cl, buf,
212 index, _sz,
213 true, worker_i);
214 if (b) {
215 deallocate_buffer(buf);
216 return true; // In normal case, go on to next buffer.
217 } else {
218 enqueue_complete_buffer(buf, index);
219 return false;
220 }
221 } else {
222 return false;
223 }
224 }
225
226 bool DirtyCardQueueSet::apply_closure_to_completed_buffer(CardTableEntryClosure* cl,
227 uint worker_i,
228 int stop_at,
229 bool during_pause) {
230 assert(!during_pause || stop_at == 0, "Should not leave any completed buffers during a pause");
231 BufferNode* nd = get_completed_buffer(stop_at);
232 bool res = apply_closure_to_completed_buffer_helper(cl, worker_i, nd);
233 if (res) Atomic::inc(&_processed_buffers_rs_thread);
234 return res;
235 }
236
237 void DirtyCardQueueSet::apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl) {
238 BufferNode* nd = _completed_buffers_head;
239 while (nd != NULL) {
240 bool b =
241 DirtyCardQueue::apply_closure_to_buffer(cl,
242 BufferNode::make_buffer_from_node(nd),
243 0, _sz, false);
244 guarantee(b, "Should not stop early.");
245 nd = nd->next();
246 }
247 }
248
249 void DirtyCardQueueSet::par_apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl) {
250 BufferNode* nd = _cur_par_buffer_node;
251 while (nd != NULL) {
252 BufferNode* next = (BufferNode*)nd->next();
253 BufferNode* actual = (BufferNode*)Atomic::cmpxchg_ptr((void*)next, (volatile void*)&_cur_par_buffer_node, (void*)nd);
254 if (actual == nd) {
255 bool b =
256 DirtyCardQueue::apply_closure_to_buffer(cl,
257 BufferNode::make_buffer_from_node(actual),
258 0, _sz, false);
259 guarantee(b, "Should not stop early.");
260 nd = next;
261 } else {
262 nd = actual;
263 }
264 }
265 }
266
267 // Deallocates any completed log buffers
268 void DirtyCardQueueSet::clear() {
269 BufferNode* buffers_to_delete = NULL;
270 {
271 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
272 while (_completed_buffers_head != NULL) {
273 BufferNode* nd = _completed_buffers_head;
274 _completed_buffers_head = nd->next();
275 nd->set_next(buffers_to_delete);
276 buffers_to_delete = nd;
277 }
278 _n_completed_buffers = 0;
279 _completed_buffers_tail = NULL;
280 DEBUG_ONLY(assert_completed_buffer_list_len_correct_locked());
281 }
282 while (buffers_to_delete != NULL) {
283 BufferNode* nd = buffers_to_delete;
284 buffers_to_delete = nd->next();
285 deallocate_buffer(BufferNode::make_buffer_from_node(nd));
286 }
287
288 }
289
290 void DirtyCardQueueSet::abandon_logs() {
291 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
292 clear();
293 // Since abandon is done only at safepoints, we can safely manipulate
294 // these queues.
295 for (JavaThread* t = Threads::first(); t; t = t->next()) {
296 t->dirty_card_queue().reset();
297 }
298 shared_dirty_card_queue()->reset();
299 }
300
301
302 void DirtyCardQueueSet::concatenate_logs() {
303 // Iterate over all the threads, if we find a partial log add it to
304 // the global list of logs. Temporarily turn off the limit on the number
305 // of outstanding buffers.
306 int save_max_completed_queue = _max_completed_queue;
307 _max_completed_queue = max_jint;
308 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
309 for (JavaThread* t = Threads::first(); t; t = t->next()) {
310 DirtyCardQueue& dcq = t->dirty_card_queue();
311 if (dcq.size() != 0) {
312 void** buf = dcq.get_buf();
313 // We must NULL out the unused entries, then enqueue.
314 size_t limit = dcq.byte_index_to_index(dcq.get_index());
315 for (size_t i = 0; i < limit; ++i) {
316 buf[i] = NULL;
317 }
318 enqueue_complete_buffer(dcq.get_buf(), dcq.get_index());
319 dcq.reinitialize();
320 }
321 }
322 if (_shared_dirty_card_queue.size() != 0) {
323 enqueue_complete_buffer(_shared_dirty_card_queue.get_buf(),
324 _shared_dirty_card_queue.get_index());
325 _shared_dirty_card_queue.reinitialize();
326 }
327 // Restore the completed buffer queue limit.
328 _max_completed_queue = save_max_completed_queue;
329 }