1 /*
2 * Copyright (c) 2019, 2021, 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 // G1RedirtyCardsLocalQueueSet
32
G1RedirtyCardsLocalQueueSet(G1RedirtyCardsQueueSet * shared_qset)33 G1RedirtyCardsLocalQueueSet::G1RedirtyCardsLocalQueueSet(G1RedirtyCardsQueueSet* shared_qset) :
34 PtrQueueSet(shared_qset->allocator()),
35 _shared_qset(shared_qset),
36 _buffers(),
37 _queue(this)
38 {}
39
40 #ifdef ASSERT
~G1RedirtyCardsLocalQueueSet()41 G1RedirtyCardsLocalQueueSet::~G1RedirtyCardsLocalQueueSet() {
42 assert(_buffers._head == NULL, "unflushed qset");
43 assert(_buffers._tail == NULL, "invariant");
44 assert(_buffers._entry_count == 0, "invariant");
45 }
46 #endif // ASSERT
47
enqueue_completed_buffer(BufferNode * node)48 void G1RedirtyCardsLocalQueueSet::enqueue_completed_buffer(BufferNode* node) {
49 _buffers._entry_count += buffer_size() - node->index();
50 node->set_next(_buffers._head);
51 _buffers._head = node;
52 if (_buffers._tail == NULL) {
53 _buffers._tail = node;
54 }
55 }
56
enqueue(void * value)57 void G1RedirtyCardsLocalQueueSet::enqueue(void* value) {
58 if (!try_enqueue(_queue, value)) {
59 BufferNode* old_node = exchange_buffer_with_new(_queue);
60 if (old_node != nullptr) {
61 enqueue_completed_buffer(old_node);
62 }
63 retry_enqueue(_queue, value);
64 }
65 }
66
flush()67 void G1RedirtyCardsLocalQueueSet::flush() {
68 flush_queue(_queue);
69 _shared_qset->add_bufferlist(_buffers);
70 _buffers = G1BufferNodeList();
71 }
72
73 // G1RedirtyCardsLocalQueueSet::Queue
74
Queue(G1RedirtyCardsLocalQueueSet * qset)75 G1RedirtyCardsLocalQueueSet::Queue::Queue(G1RedirtyCardsLocalQueueSet* qset) :
76 PtrQueue(qset)
77 {}
78
79 #ifdef ASSERT
~Queue()80 G1RedirtyCardsLocalQueueSet::Queue::~Queue() {
81 assert(buffer() == nullptr, "unflushed queue");
82 }
83 #endif // ASSERT
84
85 // G1RedirtyCardsQueueSet
86
G1RedirtyCardsQueueSet(BufferNode::Allocator * allocator)87 G1RedirtyCardsQueueSet::G1RedirtyCardsQueueSet(BufferNode::Allocator* allocator) :
88 PtrQueueSet(allocator),
89 _list(),
90 _entry_count(0),
91 _tail(NULL)
92 DEBUG_ONLY(COMMA _collecting(true))
93 {}
94
~G1RedirtyCardsQueueSet()95 G1RedirtyCardsQueueSet::~G1RedirtyCardsQueueSet() {
96 verify_empty();
97 }
98
99 #ifdef ASSERT
verify_empty() const100 void G1RedirtyCardsQueueSet::verify_empty() const {
101 assert(_list.empty(), "precondition");
102 assert(_tail == NULL, "invariant");
103 assert(_entry_count == 0, "invariant");
104 }
105 #endif // ASSERT
106
all_completed_buffers() const107 BufferNode* G1RedirtyCardsQueueSet::all_completed_buffers() const {
108 DEBUG_ONLY(_collecting = false;)
109 return _list.top();
110 }
111
take_all_completed_buffers()112 G1BufferNodeList G1RedirtyCardsQueueSet::take_all_completed_buffers() {
113 DEBUG_ONLY(_collecting = false;)
114 G1BufferNodeList result(_list.pop_all(), _tail, _entry_count);
115 _tail = NULL;
116 _entry_count = 0;
117 DEBUG_ONLY(_collecting = true;)
118 return result;
119 }
120
update_tail(BufferNode * node)121 void G1RedirtyCardsQueueSet::update_tail(BufferNode* node) {
122 // Node is the tail of a (possibly single element) list just prepended to
123 // _list. If, after that prepend, node's follower is NULL, then node is
124 // also the tail of _list, so record it as such.
125 if (node->next() == NULL) {
126 assert(_tail == NULL, "invariant");
127 _tail = node;
128 }
129 }
130
enqueue_completed_buffer(BufferNode * node)131 void G1RedirtyCardsQueueSet::enqueue_completed_buffer(BufferNode* node) {
132 assert(_collecting, "precondition");
133 Atomic::add(&_entry_count, buffer_size() - node->index());
134 _list.push(*node);
135 update_tail(node);
136 }
137
add_bufferlist(const G1BufferNodeList & buffers)138 void G1RedirtyCardsQueueSet::add_bufferlist(const G1BufferNodeList& buffers) {
139 assert(_collecting, "precondition");
140 if (buffers._head != NULL) {
141 assert(buffers._tail != NULL, "invariant");
142 Atomic::add(&_entry_count, buffers._entry_count);
143 _list.prepend(*buffers._head, *buffers._tail);
144 update_tail(buffers._tail);
145 }
146 }
147