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/satbQueue.hpp" 27 #include "memory/allocation.inline.hpp" 28 #include "memory/sharedHeap.hpp" 29 #include "runtime/mutexLocker.hpp" 30 #include "runtime/thread.hpp" 31 32 void ObjPtrQueue::apply_closure(ObjectClosure* cl) { 33 if (_buf != NULL) { 34 apply_closure_to_buffer(cl, _buf, _index, _sz); 35 _index = _sz; 36 } 37 } 38 39 void ObjPtrQueue::apply_closure_to_buffer(ObjectClosure* cl, 40 void** buf, size_t index, size_t sz) { 41 if (cl == NULL) return; 42 for (size_t i = index; i < sz; i += oopSize) { 43 oop obj = (oop)buf[byte_index_to_index((int)i)]; 44 // There can be NULL entries because of destructors. 45 if (obj != NULL) { 46 cl->do_object(obj); 47 } 48 } 49 } 50 51 #ifdef ASSERT 52 void ObjPtrQueue::verify_oops_in_buffer() { 53 if (_buf == NULL) return; 54 for (size_t i = _index; i < _sz; i += oopSize) { 55 oop obj = (oop)_buf[byte_index_to_index((int)i)]; 56 assert(obj != NULL && obj->is_oop(true /* ignore mark word */), 57 "Not an oop"); 58 } 59 } 60 #endif 61 62 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away 63 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list 64 #endif // _MSC_VER 65 66 67 SATBMarkQueueSet::SATBMarkQueueSet() : 68 PtrQueueSet(), 69 _closure(NULL), _par_closures(NULL), 70 _shared_satb_queue(this, true /*perm*/) 71 {} 72 73 void SATBMarkQueueSet::initialize(Monitor* cbl_mon, Mutex* fl_lock, 74 int process_completed_threshold, 75 Mutex* lock) { 76 PtrQueueSet::initialize(cbl_mon, fl_lock, process_completed_threshold, -1); 77 _shared_satb_queue.set_lock(lock); 78 if (ParallelGCThreads > 0) { 79 _par_closures = NEW_C_HEAP_ARRAY(ObjectClosure*, ParallelGCThreads); 80 } 81 } 82 83 84 void SATBMarkQueueSet::handle_zero_index_for_thread(JavaThread* t) { 85 DEBUG_ONLY(t->satb_mark_queue().verify_oops_in_buffer();) 86 t->satb_mark_queue().handle_zero_index(); 87 } 88 89 #ifdef ASSERT 90 void SATBMarkQueueSet::dump_active_values(JavaThread* first, 91 bool expected_active) { 92 gclog_or_tty->print_cr("SATB queue active values for Java Threads"); 93 gclog_or_tty->print_cr(" SATB queue set: active is %s", 94 (is_active()) ? "TRUE" : "FALSE"); 95 gclog_or_tty->print_cr(" expected_active is %s", 96 (expected_active) ? "TRUE" : "FALSE"); 97 for (JavaThread* t = first; t; t = t->next()) { 98 bool active = t->satb_mark_queue().is_active(); 99 gclog_or_tty->print_cr(" thread %s, active is %s", 100 t->name(), (active) ? "TRUE" : "FALSE"); 101 } 102 } 103 #endif // ASSERT 104 105 void SATBMarkQueueSet::set_active_all_threads(bool b, 106 bool expected_active) { 107 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint."); 108 JavaThread* first = Threads::first(); 109 110 #ifdef ASSERT 111 if (_all_active != expected_active) { 112 dump_active_values(first, expected_active); 113 114 // I leave this here as a guarantee, instead of an assert, so 115 // that it will still be compiled in if we choose to uncomment 116 // the #ifdef ASSERT in a product build. The whole block is 117 // within an #ifdef ASSERT so the guarantee will not be compiled 118 // in a product build anyway. 119 guarantee(false, 120 "SATB queue set has an unexpected active value"); 121 } 122 #endif // ASSERT 123 _all_active = b; 124 125 for (JavaThread* t = first; t; t = t->next()) { 126 #ifdef ASSERT 127 bool active = t->satb_mark_queue().is_active(); 128 if (active != expected_active) { 129 dump_active_values(first, expected_active); 130 131 // I leave this here as a guarantee, instead of an assert, so 132 // that it will still be compiled in if we choose to uncomment 133 // the #ifdef ASSERT in a product build. The whole block is 134 // within an #ifdef ASSERT so the guarantee will not be compiled 135 // in a product build anyway. 136 guarantee(false, 137 "thread has an unexpected active value in its SATB queue"); 138 } 139 #endif // ASSERT 140 t->satb_mark_queue().set_active(b); 141 } 142 } 143 144 void SATBMarkQueueSet::set_closure(ObjectClosure* closure) { 145 _closure = closure; 146 } 147 148 void SATBMarkQueueSet::set_par_closure(int i, ObjectClosure* par_closure) { 149 assert(ParallelGCThreads > 0 && _par_closures != NULL, "Precondition"); 150 _par_closures[i] = par_closure; 151 } 152 153 void SATBMarkQueueSet::iterate_closure_all_threads() { 154 for(JavaThread* t = Threads::first(); t; t = t->next()) { 155 t->satb_mark_queue().apply_closure(_closure); 156 } 157 shared_satb_queue()->apply_closure(_closure); 158 } 159 160 void SATBMarkQueueSet::par_iterate_closure_all_threads(int worker) { 161 SharedHeap* sh = SharedHeap::heap(); 162 int parity = sh->strong_roots_parity(); 163 164 for(JavaThread* t = Threads::first(); t; t = t->next()) { 165 if (t->claim_oops_do(true, parity)) { 166 t->satb_mark_queue().apply_closure(_par_closures[worker]); 167 } 168 } 169 // We'll have worker 0 do this one. 170 if (worker == 0) { 171 shared_satb_queue()->apply_closure(_par_closures[0]); 172 } 173 } 174 175 bool SATBMarkQueueSet::apply_closure_to_completed_buffer_work(bool par, 176 int worker) { 177 BufferNode* nd = NULL; 178 { 179 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag); 180 if (_completed_buffers_head != NULL) { 181 nd = _completed_buffers_head; 182 _completed_buffers_head = nd->next(); 183 if (_completed_buffers_head == NULL) _completed_buffers_tail = NULL; 184 _n_completed_buffers--; 185 if (_n_completed_buffers == 0) _process_completed = false; 186 } 187 } 188 ObjectClosure* cl = (par ? _par_closures[worker] : _closure); 189 if (nd != NULL) { 190 void **buf = BufferNode::make_buffer_from_node(nd); 191 ObjPtrQueue::apply_closure_to_buffer(cl, buf, 0, _sz); 192 deallocate_buffer(buf); 193 return true; 194 } else { 195 return false; 196 } 197 } 198 199 void SATBMarkQueueSet::abandon_partial_marking() { 200 BufferNode* buffers_to_delete = NULL; 201 { 202 MutexLockerEx x(_cbl_mon, Mutex::_no_safepoint_check_flag); 203 while (_completed_buffers_head != NULL) { 204 BufferNode* nd = _completed_buffers_head; 205 _completed_buffers_head = nd->next(); 206 nd->set_next(buffers_to_delete); 207 buffers_to_delete = nd; 208 } 209 _completed_buffers_tail = NULL; 210 _n_completed_buffers = 0; 211 DEBUG_ONLY(assert_completed_buffer_list_len_correct_locked()); 212 } 213 while (buffers_to_delete != NULL) { 214 BufferNode* nd = buffers_to_delete; 215 buffers_to_delete = nd->next(); 216 deallocate_buffer(BufferNode::make_buffer_from_node(nd)); 217 } 218 assert(SafepointSynchronize::is_at_safepoint(), "Must be at safepoint."); 219 // So we can safely manipulate these queues. 220 for (JavaThread* t = Threads::first(); t; t = t->next()) { 221 t->satb_mark_queue().reset(); 222 } 223 shared_satb_queue()->reset(); 224 }