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 "runtime/vmThread.hpp"
33 #include "runtime/vm_operations.hpp"
34 #include "utilities/workgroup.hpp"
35
36 bool DirtyCardQueue::apply_closure(CardTableEntryClosure* cl,
37 bool consume,
38 size_t worker_i) {
39 bool res = true;
40 if (_buf != NULL) {
41 res = apply_closure_to_buffer(cl, _buf, _index, _sz,
42 consume,
43 (int) worker_i);
44 if (res && consume) _index = _sz;
45 }
46 return res;
47 }
48
49 bool DirtyCardQueue::apply_closure_to_buffer(CardTableEntryClosure* cl,
50 void** buf,
51 size_t index, size_t sz,
52 bool consume,
53 int worker_i) {
54 if (cl == NULL) return true;
55 for (size_t i = index; i < sz; i += oopSize) {
56 int ind = byte_index_to_index((int)i);
57 jbyte* card_ptr = (jbyte*)buf[ind];
58 if (card_ptr != NULL) {
59 // Set the entry to null, so we don't do it again (via the test
60 // above) if we reconsider this buffer.
61 if (consume) buf[ind] = NULL;
62 if (!cl->do_card_ptr(card_ptr, worker_i)) return false;
63 }
64 }
65 return true;
66 }
67
68 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
69 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
70 #endif // _MSC_VER
71
72 DirtyCardQueueSet::DirtyCardQueueSet(bool notify_when_complete) :
73 PtrQueueSet(notify_when_complete),
74 _closure(NULL),
75 _shared_dirty_card_queue(this, true /*perm*/),
76 _free_ids(NULL),
77 _processed_buffers_mut(0), _processed_buffers_rs_thread(0)
78 {
79 _all_active = true;
80 }
81
82 // Determines how many mutator threads can process the buffers in parallel.
83 size_t DirtyCardQueueSet::num_par_ids() {
84 return os::processor_count();
85 }
86
87 void DirtyCardQueueSet::initialize(Monitor* cbl_mon, Mutex* fl_lock,
88 int process_completed_threshold,
89 int max_completed_queue,
90 Mutex* lock, PtrQueueSet* fl_owner) {
91 PtrQueueSet::initialize(cbl_mon, fl_lock, process_completed_threshold,
92 max_completed_queue, fl_owner);
93 set_buffer_size(G1UpdateBufferSize);
94 _shared_dirty_card_queue.set_lock(lock);
95 _free_ids = new FreeIdSet((int) num_par_ids(), _cbl_mon);
96 }
97
98 void DirtyCardQueueSet::handle_zero_index_for_thread(JavaThread* t) {
99 t->dirty_card_queue().handle_zero_index();
100 }
101
102 void DirtyCardQueueSet::set_closure(CardTableEntryClosure* closure) {
103 _closure = closure;
104 }
105
106 void DirtyCardQueueSet::iterate_closure_all_threads(bool consume,
107 size_t worker_i) {
108 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
109 for(JavaThread* t = Threads::first(); t; t = t->next()) {
110 bool b = t->dirty_card_queue().apply_closure(_closure, consume);
111 guarantee(b, "Should not be interrupted.");
112 }
113 bool b = shared_dirty_card_queue()->apply_closure(_closure,
114 consume,
115 worker_i);
116 guarantee(b, "Should not be interrupted.");
117 }
118
119 bool DirtyCardQueueSet::mut_process_buffer(void** buf) {
120 VMThread::execute (new VM_ForceAsyncSafepoint());
121 return false;
122 #if 0
123 // Used to determine if we had already claimed a par_id
124 // before entering this method.
125 bool already_claimed = false;
126
127 // We grab the current JavaThread.
128 JavaThread* thread = JavaThread::current();
129
130 // We get the the number of any par_id that this thread
131 // might have already claimed.
132 int worker_i = thread->get_claimed_par_id();
133
134 // If worker_i is not -1 then the thread has already claimed
135 // a par_id. We make note of it using the already_claimed value
136 if (worker_i != -1) {
137 already_claimed = true;
138 } else {
139
140 // Otherwise we need to claim a par id
141 worker_i = _free_ids->claim_par_id();
142
143 // And store the par_id value in the thread
144 thread->set_claimed_par_id(worker_i);
145 }
146
147 bool b = false;
148 if (worker_i != -1) {
149 b = DirtyCardQueue::apply_closure_to_buffer(_closure, buf, 0,
150 _sz, true, worker_i);
151 if (b) Atomic::inc(&_processed_buffers_mut);
152
153 // If we had not claimed an id before entering the method
154 // then we must release the id.
155 if (!already_claimed) {
156
157 // we release the id
158 _free_ids->release_par_id(worker_i);
159
160 // and set the claimed_id in the thread to -1
161 thread->set_claimed_par_id(-1);
162 }
163 }
164 return b;
165 #endif
166 }
167
168
169 BufferNode*
170 DirtyCardQueueSet::get_completed_buffer(int stop_at) {
171 BufferNode* nd = NULL;
172 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
173
174 if ((int)_n_completed_buffers <= stop_at) {
175 _process_completed = false;
176 return NULL;
177 }
178
179 if (_completed_buffers_head != NULL) {
180 nd = _completed_buffers_head;
181 _completed_buffers_head = nd->next();
182 if (_completed_buffers_head == NULL)
183 _completed_buffers_tail = NULL;
184 _n_completed_buffers--;
185 assert(_n_completed_buffers >= 0, "Invariant");
186 }
187 debug_only(assert_completed_buffer_list_len_correct_locked());
188 return nd;
189 }
190
191 bool DirtyCardQueueSet::
192 apply_closure_to_completed_buffer_helper(CardTableEntryClosure* cl,
193 int worker_i,
194 BufferNode* nd) {
195 if (nd != NULL) {
196 void **buf = BufferNode::make_buffer_from_node(nd);
197 size_t index = nd->index();
198 bool b =
199 DirtyCardQueue::apply_closure_to_buffer(cl, buf,
200 index, _sz,
201 true, worker_i);
202 if (b) {
203 deallocate_buffer(buf);
204 return true; // In normal case, go on to next buffer.
205 } else {
206 enqueue_complete_buffer(buf, index);
207 return false;
208 }
209 } else {
210 return false;
211 }
212 }
213
214 bool DirtyCardQueueSet::apply_closure_to_completed_buffer(CardTableEntryClosure* cl,
215 int worker_i,
216 int stop_at,
217 bool during_pause) {
218 assert(!during_pause || stop_at == 0, "Should not leave any completed buffers during a pause");
219 BufferNode* nd = get_completed_buffer(stop_at);
220 bool res = apply_closure_to_completed_buffer_helper(cl, worker_i, nd);
221 if (res) Atomic::inc(&_processed_buffers_rs_thread);
222 return res;
223 }
224
225 bool DirtyCardQueueSet::apply_closure_to_completed_buffer(int worker_i,
226 int stop_at,
227 bool during_pause) {
228 return apply_closure_to_completed_buffer(_closure, worker_i,
229 stop_at, during_pause);
230 }
231
232 void DirtyCardQueueSet::apply_closure_to_all_completed_buffers() {
233 BufferNode* nd = _completed_buffers_head;
234 while (nd != NULL) {
235 bool b =
236 DirtyCardQueue::apply_closure_to_buffer(_closure,
237 BufferNode::make_buffer_from_node(nd),
238 0, _sz, false);
239 guarantee(b, "Should not stop early.");
240 nd = nd->next();
241 }
242 }
243
244 // Deallocates any completed log buffers
245 void DirtyCardQueueSet::clear() {
246 BufferNode* buffers_to_delete = NULL;
247 {
248 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag);
249 while (_completed_buffers_head != NULL) {
250 BufferNode* nd = _completed_buffers_head;
251 _completed_buffers_head = nd->next();
252 nd->set_next(buffers_to_delete);
253 buffers_to_delete = nd;
254 }
255 _n_completed_buffers = 0;
256 _completed_buffers_tail = NULL;
257 debug_only(assert_completed_buffer_list_len_correct_locked());
258 }
259 while (buffers_to_delete != NULL) {
260 BufferNode* nd = buffers_to_delete;
261 buffers_to_delete = nd->next();
262 deallocate_buffer(BufferNode::make_buffer_from_node(nd));
263 }
264
265 }
266
267 void DirtyCardQueueSet::abandon_logs() {
268 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
269 clear();
270 // Since abandon is done only at safepoints, we can safely manipulate
271 // these queues.
272 for (JavaThread* t = Threads::first(); t; t = t->next()) {
273 t->dirty_card_queue().reset();
274 }
275 shared_dirty_card_queue()->reset();
276 }
277
278
279 void DirtyCardQueueSet::concatenate_logs() {
280 // Iterate over all the threads, if we find a partial log add it to
281 // the global list of logs. Temporarily turn off the limit on the number
282 // of outstanding buffers.
283 int save_max_completed_queue = _max_completed_queue;
284 _max_completed_queue = max_jint;
285 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint.");
286 for (JavaThread* t = Threads::first(); t; t = t->next()) {
287 DirtyCardQueue& dcq = t->dirty_card_queue();
288 if (dcq.size() != 0) {
289 void **buf = t->dirty_card_queue().get_buf();
290 // We must NULL out the unused entries, then enqueue.
291 for (size_t i = 0; i < t->dirty_card_queue().get_index(); i += oopSize) {
292 buf[PtrQueue::byte_index_to_index((int)i)] = NULL;
293 }
294 enqueue_complete_buffer(dcq.get_buf(), dcq.get_index());
295 dcq.reinitialize();
296 }
297 }
298 if (_shared_dirty_card_queue.size() != 0) {
299 enqueue_complete_buffer(_shared_dirty_card_queue.get_buf(),
300 _shared_dirty_card_queue.get_index());
301 _shared_dirty_card_queue.reinitialize();
302 }
303 // Restore the completed buffer queue limit.
304 _max_completed_queue = save_max_completed_queue;
305 }