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