1 /* 2 * Copyright (c) 2019, 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/g1/g1RedirtyCardsQueue.hpp" 27 #include "runtime/atomic.hpp" 28 #include "utilities/debug.hpp" 29 #include "utilities/macros.hpp" 30 31 // G1RedirtyCardsQueueBase::LocalQSet 32 33 G1RedirtyCardsQueueBase::LocalQSet::LocalQSet(G1RedirtyCardsQueueSet* shared_qset) : 34 PtrQueueSet(), 35 _shared_qset(shared_qset), 36 _buffers() 37 { 38 PtrQueueSet::initialize(_shared_qset->allocator()); 39 } 40 41 G1RedirtyCardsQueueBase::LocalQSet::~LocalQSet() { 42 assert(_buffers._head == NULL, "unflushed qset"); 43 assert(_buffers._tail == NULL, "invariant"); 44 assert(_buffers._entry_count == 0, "invariant"); 45 } 46 47 void G1RedirtyCardsQueueBase::LocalQSet::enqueue_completed_buffer(BufferNode* node) { 48 _buffers._entry_count += buffer_size() - node->index(); 49 node->set_next(_buffers._head); 50 _buffers._head = node; 51 if (_buffers._tail == NULL) { 52 _buffers._tail = node; 53 } 54 } 55 56 G1BufferNodeList G1RedirtyCardsQueueBase::LocalQSet::take_all_completed_buffers() { 57 G1BufferNodeList result = _buffers; 58 _buffers = G1BufferNodeList(); 59 return result; 60 } 61 62 void G1RedirtyCardsQueueBase::LocalQSet::flush() { 63 _shared_qset->merge_bufferlist(this); 64 } 65 66 // G1RedirtyCardsQueue 67 68 G1RedirtyCardsQueue::G1RedirtyCardsQueue(G1RedirtyCardsQueueSet* qset) : 69 G1RedirtyCardsQueueBase(qset), // Init _local_qset before passing to PtrQueue. 70 PtrQueue(&_local_qset, true /* active (always) */) 71 {} 72 73 G1RedirtyCardsQueue::~G1RedirtyCardsQueue() { 74 flush(); 75 } 76 77 void G1RedirtyCardsQueue::handle_completed_buffer() { 78 enqueue_completed_buffer(); 79 } 80 81 void G1RedirtyCardsQueue::flush() { 82 flush_impl(); 83 _local_qset.flush(); 84 } 85 86 // G1RedirtyCardsQueueSet 87 88 G1RedirtyCardsQueueSet::G1RedirtyCardsQueueSet(BufferNode::Allocator* allocator) : 89 PtrQueueSet(), 90 _list(), 91 _entry_count(0), 92 _tail(NULL) 93 DEBUG_ONLY(COMMA _collecting(true)) 94 { 95 initialize(allocator); 96 } 97 98 G1RedirtyCardsQueueSet::~G1RedirtyCardsQueueSet() { 99 verify_empty(); 100 } 101 102 #ifdef ASSERT 103 void G1RedirtyCardsQueueSet::verify_empty() const { 104 assert(_list.empty(), "precondition"); 105 assert(_tail == NULL, "invariant"); 106 assert(_entry_count == 0, "invariant"); 107 } 108 #endif // ASSERT 109 110 BufferNode* G1RedirtyCardsQueueSet::all_completed_buffers() const { 111 DEBUG_ONLY(_collecting = false;) 112 return _list.top(); 113 } 114 115 G1BufferNodeList G1RedirtyCardsQueueSet::take_all_completed_buffers() { 116 DEBUG_ONLY(_collecting = false;) 117 G1BufferNodeList result(_list.pop_all(), _tail, _entry_count); 118 _tail = NULL; 119 _entry_count = 0; 120 DEBUG_ONLY(_collecting = true;) 121 return result; 122 } 123 124 void G1RedirtyCardsQueueSet::update_tail(BufferNode* node) { 125 // Node is the tail of a (possibly single element) list just prepended to 126 // _list. If, after that prepend, node's follower is NULL, then node is 127 // also the tail of _list, so record it as such. 128 if (node->next() == NULL) { 129 assert(_tail == NULL, "invariant"); 130 _tail = node; 131 } 132 } 133 134 void G1RedirtyCardsQueueSet::enqueue_completed_buffer(BufferNode* node) { 135 assert(_collecting, "precondition"); 136 Atomic::add(buffer_size() - node->index(), &_entry_count); 137 _list.push(*node); 138 update_tail(node); 139 } 140 141 void G1RedirtyCardsQueueSet::merge_bufferlist(LocalQSet* src) { 142 assert(_collecting, "precondition"); 143 const G1BufferNodeList from = src->take_all_completed_buffers(); 144 if (from._head != NULL) { 145 assert(from._tail != NULL, "invariant"); 146 Atomic::add(from._entry_count, &_entry_count); 147 _list.prepend(*from._head, *from._tail); 148 update_tail(from._tail); 149 } 150 }