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 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away 68 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list 69 #endif // _MSC_VER 70 71 DirtyCardQueueSet::DirtyCardQueueSet(bool notify_when_complete) : 72 PtrQueueSet(notify_when_complete), 73 _mut_process_closure(NULL), 74 _shared_dirty_card_queue(this, true /*perm*/), 75 _free_ids(NULL), 76 _processed_buffers_mut(0), _processed_buffers_rs_thread(0) 77 { 78 _all_active = true; 79 } 80 81 // Determines how many mutator threads can process the buffers in parallel. 82 uint DirtyCardQueueSet::num_par_ids() { 83 return (uint)os::processor_count(); 84 } 85 86 void DirtyCardQueueSet::initialize(CardTableEntryClosure* cl, Monitor* cbl_mon, Mutex* fl_lock, 87 int process_completed_threshold, 88 int max_completed_queue, 89 Mutex* lock, PtrQueueSet* fl_owner) { 90 _mut_process_closure = cl; 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::iterate_closure_all_threads(CardTableEntryClosure* cl, 103 bool consume, 104 uint worker_i) { 105 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint."); 106 for(JavaThread* t = Threads::first(); t; t = t->next()) { 107 bool b = t->dirty_card_queue().apply_closure(cl, consume); 108 guarantee(b, "Should not be interrupted."); 109 } 110 bool b = shared_dirty_card_queue()->apply_closure(cl, 111 consume, 112 worker_i); 113 guarantee(b, "Should not be interrupted."); 114 } 115 116 bool DirtyCardQueueSet::mut_process_buffer(void** buf) { 117 118 // Used to determine if we had already claimed a par_id 119 // before entering this method. 120 bool already_claimed = false; 121 122 // We grab the current JavaThread. 123 JavaThread* thread = JavaThread::current(); 124 125 // We get the the number of any par_id that this thread 126 // might have already claimed. 127 uint worker_i = thread->get_claimed_par_id(); 128 129 // If worker_i is not UINT_MAX then the thread has already claimed 130 // a par_id. We make note of it using the already_claimed value 131 if (worker_i != UINT_MAX) { 132 already_claimed = true; 133 } else { 134 135 // Otherwise we need to claim a par id 136 worker_i = _free_ids->claim_par_id(); 137 138 // And store the par_id value in the thread 139 thread->set_claimed_par_id(worker_i); 140 } 141 142 bool b = false; 143 if (worker_i != UINT_MAX) { 144 b = DirtyCardQueue::apply_closure_to_buffer(_mut_process_closure, buf, 0, 145 _sz, true, worker_i); 146 if (b) Atomic::inc(&_processed_buffers_mut); 147 148 // If we had not claimed an id before entering the method 149 // then we must release the id. 150 if (!already_claimed) { 151 152 // we release the id 153 _free_ids->release_par_id(worker_i); 154 155 // and set the claimed_id in the thread to UINT_MAX 156 thread->set_claimed_par_id(UINT_MAX); 157 } 158 } 159 return b; 160 } 161 162 163 BufferNode* 164 DirtyCardQueueSet::get_completed_buffer(int stop_at) { 165 BufferNode* nd = NULL; 166 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag); 167 168 if ((int)_n_completed_buffers <= stop_at) { 169 _process_completed = false; 170 return NULL; 171 } 172 173 if (_completed_buffers_head != NULL) { 174 nd = _completed_buffers_head; 175 _completed_buffers_head = nd->next(); 176 if (_completed_buffers_head == NULL) 177 _completed_buffers_tail = NULL; 178 _n_completed_buffers--; 179 assert(_n_completed_buffers >= 0, "Invariant"); 180 } 181 debug_only(assert_completed_buffer_list_len_correct_locked()); 182 return nd; 183 } 184 185 bool DirtyCardQueueSet:: 186 apply_closure_to_completed_buffer_helper(CardTableEntryClosure* cl, 187 uint worker_i, 188 BufferNode* nd) { 189 if (nd != NULL) { 190 void **buf = BufferNode::make_buffer_from_node(nd); 191 size_t index = nd->index(); 192 bool b = 193 DirtyCardQueue::apply_closure_to_buffer(cl, buf, 194 index, _sz, 195 true, worker_i); 196 if (b) { 197 deallocate_buffer(buf); 198 return true; // In normal case, go on to next buffer. 199 } else { 200 enqueue_complete_buffer(buf, index); 201 return false; 202 } 203 } else { 204 return false; 205 } 206 } 207 208 bool DirtyCardQueueSet::apply_closure_to_completed_buffer(CardTableEntryClosure* cl, 209 uint worker_i, 210 int stop_at, 211 bool during_pause) { 212 assert(!during_pause || stop_at == 0, "Should not leave any completed buffers during a pause"); 213 BufferNode* nd = get_completed_buffer(stop_at); 214 bool res = apply_closure_to_completed_buffer_helper(cl, worker_i, nd); 215 if (res) Atomic::inc(&_processed_buffers_rs_thread); 216 return res; 217 } 218 219 void DirtyCardQueueSet::apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl) { 220 BufferNode* nd = _completed_buffers_head; 221 while (nd != NULL) { 222 bool b = 223 DirtyCardQueue::apply_closure_to_buffer(cl, 224 BufferNode::make_buffer_from_node(nd), 225 0, _sz, false); 226 guarantee(b, "Should not stop early."); 227 nd = nd->next(); 228 } 229 } 230 231 void DirtyCardQueueSet::par_apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl) { 232 BufferNode* nd = _cur_par_buffer_node; 233 while (nd != NULL) { 234 BufferNode* next = (BufferNode*)nd->next(); 235 BufferNode* actual = (BufferNode*)Atomic::cmpxchg_ptr((void*)next, (volatile void*)&_cur_par_buffer_node, (void*)nd); 236 if (actual == nd) { 237 bool b = 238 DirtyCardQueue::apply_closure_to_buffer(cl, 239 BufferNode::make_buffer_from_node(actual), 240 0, _sz, false); 241 guarantee(b, "Should not stop early."); 242 nd = next; 243 } else { 244 nd = actual; 245 } 246 } 247 } 248 249 // Deallocates any completed log buffers 250 void DirtyCardQueueSet::clear() { 251 BufferNode* buffers_to_delete = NULL; 252 { 253 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag); 254 while (_completed_buffers_head != NULL) { 255 BufferNode* nd = _completed_buffers_head; 256 _completed_buffers_head = nd->next(); 257 nd->set_next(buffers_to_delete); 258 buffers_to_delete = nd; 259 } 260 _n_completed_buffers = 0; 261 _completed_buffers_tail = NULL; 262 debug_only(assert_completed_buffer_list_len_correct_locked()); 263 } 264 while (buffers_to_delete != NULL) { 265 BufferNode* nd = buffers_to_delete; 266 buffers_to_delete = nd->next(); 267 deallocate_buffer(BufferNode::make_buffer_from_node(nd)); 268 } 269 270 } 271 272 void DirtyCardQueueSet::abandon_logs() { 273 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint."); 274 clear(); 275 // Since abandon is done only at safepoints, we can safely manipulate 276 // these queues. 277 for (JavaThread* t = Threads::first(); t; t = t->next()) { 278 t->dirty_card_queue().reset(); 279 } 280 shared_dirty_card_queue()->reset(); 281 } 282 283 284 void DirtyCardQueueSet::concatenate_logs() { 285 // Iterate over all the threads, if we find a partial log add it to 286 // the global list of logs. Temporarily turn off the limit on the number 287 // of outstanding buffers. 288 int save_max_completed_queue = _max_completed_queue; 289 _max_completed_queue = max_jint; 290 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint."); 291 for (JavaThread* t = Threads::first(); t; t = t->next()) { 292 DirtyCardQueue& dcq = t->dirty_card_queue(); 293 if (dcq.size() != 0) { 294 void **buf = t->dirty_card_queue().get_buf(); 295 // We must NULL out the unused entries, then enqueue. 296 for (size_t i = 0; i < t->dirty_card_queue().get_index(); i += oopSize) { 297 buf[PtrQueue::byte_index_to_index((int)i)] = NULL; 298 } 299 enqueue_complete_buffer(dcq.get_buf(), dcq.get_index()); 300 dcq.reinitialize(); 301 } 302 } 303 if (_shared_dirty_card_queue.size() != 0) { 304 enqueue_complete_buffer(_shared_dirty_card_queue.get_buf(), 305 _shared_dirty_card_queue.get_index()); 306 _shared_dirty_card_queue.reinitialize(); 307 } 308 // Restore the completed buffer queue limit. 309 _max_completed_queue = save_max_completed_queue; 310 }