1 /* 2 * Copyright (c) 2001, 2017, 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 #ifndef SHARE_VM_GC_G1_DIRTYCARDQUEUE_HPP 26 #define SHARE_VM_GC_G1_DIRTYCARDQUEUE_HPP 27 28 #include "gc/g1/ptrQueue.hpp" 29 #include "memory/allocation.hpp" 30 31 class FreeIdSet; 32 class DirtyCardQueueSet; 33 34 // A closure class for processing card table entries. Note that we don't 35 // require these closure objects to be stack-allocated. 36 class CardTableEntryClosure: public CHeapObj<mtGC> { 37 public: 38 // Process the card whose card table entry is "card_ptr". If returns 39 // "false", terminate the iteration early. 40 virtual bool do_card_ptr(jbyte* card_ptr, uint worker_i) = 0; 41 }; 42 43 // A ptrQueue whose elements are "oops", pointers to object heads. 44 class DirtyCardQueue: public PtrQueue { 45 public: 46 DirtyCardQueue(DirtyCardQueueSet* qset, bool permanent = false); 47 48 // Flush before destroying; queue may be used to capture pending work while 49 // doing something else, with auto-flush on completion. 50 ~DirtyCardQueue(); 51 52 // Process queue entries and release resources. 53 void flush() { flush_impl(); } 54 55 // Compiler support. 56 static ByteSize byte_offset_of_index() { 57 return PtrQueue::byte_offset_of_index<DirtyCardQueue>(); 58 } 59 using PtrQueue::byte_width_of_index; 60 61 static ByteSize byte_offset_of_buf() { 62 return PtrQueue::byte_offset_of_buf<DirtyCardQueue>(); 63 } 64 using PtrQueue::byte_width_of_buf; 65 66 }; 67 68 69 70 class DirtyCardQueueSet: public PtrQueueSet { 71 // The closure used in mut_process_buffer(). 72 CardTableEntryClosure* _mut_process_closure; 73 74 DirtyCardQueue _shared_dirty_card_queue; 75 76 // Apply the closure to the elements of "node" from it's index to 77 // buffer_size. If all closure applications return true, then 78 // returns true. Stops processing after the first closure 79 // application that returns false, and returns false from this 80 // function. If "consume" is true, the node's index is updated to 81 // exclude the processed elements, e.g. up to the element for which 82 // the closure returned false. 83 bool apply_closure_to_buffer(CardTableEntryClosure* cl, 84 BufferNode* node, 85 bool consume, 86 uint worker_i = 0); 87 88 bool mut_process_buffer(BufferNode* node); 89 90 // Protected by the _cbl_mon. 91 FreeIdSet* _free_ids; 92 93 // The number of completed buffers processed by mutator and rs thread, 94 // respectively. 95 jint _processed_buffers_mut; 96 jint _processed_buffers_rs_thread; 97 98 // Current buffer node used for parallel iteration. 99 BufferNode* volatile _cur_par_buffer_node; 100 101 void concatenate_log(DirtyCardQueue& dcq); 102 103 public: 104 DirtyCardQueueSet(bool notify_when_complete = true); 105 106 void initialize(CardTableEntryClosure* cl, 107 Monitor* cbl_mon, 108 Mutex* fl_lock, 109 int process_completed_threshold, 110 int max_completed_queue, 111 Mutex* lock, 112 DirtyCardQueueSet* fl_owner, 113 bool init_free_ids = false); 114 115 // The number of parallel ids that can be claimed to allow collector or 116 // mutator threads to do card-processing work. 117 static uint num_par_ids(); 118 119 static void handle_zero_index_for_thread(JavaThread* t); 120 121 // If there are more than stop_at completed buffers, pop one, apply 122 // the specified closure to its active elements, and return true. 123 // Otherwise return false. 124 // 125 // A completely processed buffer is freed. However, if a closure 126 // invocation returns false, processing is stopped and the partially 127 // processed buffer (with its index updated to exclude the processed 128 // elements, e.g. up to the element for which the closure returned 129 // false) is returned to the completed buffer set. 130 // 131 // If during_pause is true, stop_at must be zero, and the closure 132 // must never return false. 133 bool apply_closure_to_completed_buffer(CardTableEntryClosure* cl, 134 uint worker_i, 135 size_t stop_at, 136 bool during_pause); 137 138 BufferNode* get_completed_buffer(size_t stop_at); 139 140 void reset_for_par_iteration() { _cur_par_buffer_node = _completed_buffers_head; } 141 // Applies the current closure to all completed buffers, non-consumptively. 142 // Can be used in parallel, all callers using the iteration state initialized 143 // by reset_for_par_iteration. 144 void par_apply_closure_to_all_completed_buffers(CardTableEntryClosure* cl); 145 146 DirtyCardQueue* shared_dirty_card_queue() { 147 return &_shared_dirty_card_queue; 148 } 149 150 // Deallocate any completed log buffers 151 void clear(); 152 153 // If a full collection is happening, reset partial logs, and ignore 154 // completed ones: the full collection will make them all irrelevant. 155 void abandon_logs(); 156 157 // If any threads have partial logs, add them to the global list of logs. 158 void concatenate_logs(); 159 void clear_n_completed_buffers() { _n_completed_buffers = 0;} 160 161 jint processed_buffers_mut() { 162 return _processed_buffers_mut; 163 } 164 jint processed_buffers_rs_thread() { 165 return _processed_buffers_rs_thread; 166 } 167 168 }; 169 170 #endif // SHARE_VM_GC_G1_DIRTYCARDQUEUE_HPP