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