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
LocalQSet(G1RedirtyCardsQueueSet * shared_qset)33 G1RedirtyCardsQueueBase::LocalQSet::LocalQSet(G1RedirtyCardsQueueSet* shared_qset) :
34 PtrQueueSet(shared_qset->allocator()),
35 _shared_qset(shared_qset),
36 _buffers()
37 {}
38
~LocalQSet()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
enqueue_completed_buffer(BufferNode * node)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
take_all_completed_buffers()54 G1BufferNodeList G1RedirtyCardsQueueBase::LocalQSet::take_all_completed_buffers() {
55 G1BufferNodeList result = _buffers;
56 _buffers = G1BufferNodeList();
57 return result;
58 }
59
flush()60 void G1RedirtyCardsQueueBase::LocalQSet::flush() {
61 _shared_qset->merge_bufferlist(this);
62 }
63
64 // G1RedirtyCardsQueue
65
G1RedirtyCardsQueue(G1RedirtyCardsQueueSet * qset)66 G1RedirtyCardsQueue::G1RedirtyCardsQueue(G1RedirtyCardsQueueSet* qset) :
67 G1RedirtyCardsQueueBase(qset), // Init _local_qset before passing to PtrQueue.
68 PtrQueue(&_local_qset, true /* active (always) */)
69 {}
70
~G1RedirtyCardsQueue()71 G1RedirtyCardsQueue::~G1RedirtyCardsQueue() {
72 flush();
73 }
74
handle_completed_buffer()75 void G1RedirtyCardsQueue::handle_completed_buffer() {
76 enqueue_completed_buffer();
77 }
78
flush()79 void G1RedirtyCardsQueue::flush() {
80 flush_impl();
81 _local_qset.flush();
82 }
83
84 // G1RedirtyCardsQueueSet
85
G1RedirtyCardsQueueSet(BufferNode::Allocator * allocator)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
~G1RedirtyCardsQueueSet()94 G1RedirtyCardsQueueSet::~G1RedirtyCardsQueueSet() {
95 verify_empty();
96 }
97
98 #ifdef ASSERT
verify_empty() const99 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
all_completed_buffers() const106 BufferNode* G1RedirtyCardsQueueSet::all_completed_buffers() const {
107 DEBUG_ONLY(_collecting = false;)
108 return _list.top();
109 }
110
take_all_completed_buffers()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
update_tail(BufferNode * node)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
enqueue_completed_buffer(BufferNode * node)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
merge_bufferlist(LocalQSet * src)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 }
147