1 /*
2 * Copyright (c) 2015, 2018, 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 #include "precompiled.hpp"
25 #include "logging/logLevel.hpp"
26 #include "logging/logOutputList.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "runtime/atomic.hpp"
29 #include "runtime/orderAccess.hpp"
30 #include "utilities/globalDefinitions.hpp"
31
increase_readers()32 jint LogOutputList::increase_readers() {
33 jint result = Atomic::add(&_active_readers, 1);
34 assert(_active_readers > 0, "Ensure we have consistent state");
35 return result;
36 }
37
decrease_readers()38 jint LogOutputList::decrease_readers() {
39 jint result = Atomic::add(&_active_readers, -1);
40 assert(result >= 0, "Ensure we have consistent state");
41 return result;
42 }
43
wait_until_no_readers() const44 void LogOutputList::wait_until_no_readers() const {
45 OrderAccess::storeload();
46 while (_active_readers != 0) {
47 // Busy wait
48 }
49 }
50
set_output_level(LogOutput * output,LogLevelType level)51 void LogOutputList::set_output_level(LogOutput* output, LogLevelType level) {
52 LogOutputNode* node = find(output);
53 if (level == LogLevel::Off && node != NULL) {
54 remove_output(node);
55 } else if (level != LogLevel::Off && node == NULL) {
56 add_output(output, level);
57 } else if (node != NULL) {
58 update_output_level(node, level);
59 }
60 }
61
find(const LogOutput * output) const62 LogOutputList::LogOutputNode* LogOutputList::find(const LogOutput* output) const {
63 for (LogOutputNode* node = _level_start[LogLevel::Last]; node != NULL; node = node->_next) {
64 if (output == node->_value) {
65 return node;
66 }
67 }
68 return NULL;
69 }
70
remove_output(LogOutputList::LogOutputNode * node)71 void LogOutputList::remove_output(LogOutputList::LogOutputNode* node) {
72 assert(node != NULL, "Node must be non-null");
73
74 // Remove node from _level_start first
75 bool found = false;
76 for (uint level = LogLevel::First; level < LogLevel::Count; level++) {
77 if (_level_start[level] == node) {
78 found = true;
79 _level_start[level] = node->_next;
80 }
81 }
82
83 // Now remove it from the linked list
84 for (LogOutputNode* cur = _level_start[LogLevel::Last]; cur != NULL; cur = cur->_next) {
85 if (cur->_next == node) {
86 found = true;
87 cur->_next = node->_next;
88 break;
89 }
90 }
91 assert(found, "Node to be removed should always be found");
92
93 wait_until_no_readers();
94 delete node;
95 }
96
add_output(LogOutput * output,LogLevelType level)97 void LogOutputList::add_output(LogOutput* output, LogLevelType level) {
98 LogOutputNode* node = new LogOutputNode();
99 node->_value = output;
100 node->_level = level;
101
102 // Set the next pointer to the first node of a lower level
103 for (node->_next = _level_start[level];
104 node->_next != NULL && node->_next->_level == level;
105 node->_next = node->_next->_next) {
106 }
107
108 // Update the _level_start index
109 for (int l = LogLevel::Last; l >= level; l--) {
110 if (_level_start[l] == NULL || _level_start[l]->_level < level) {
111 _level_start[l] = node;
112 }
113 }
114
115 // Add the node the list
116 for (LogOutputNode* cur = _level_start[LogLevel::Last]; cur != NULL; cur = cur->_next) {
117 if (cur != node && cur->_next == node->_next) {
118 cur->_next = node;
119 break;
120 }
121 }
122 }
123
update_output_level(LogOutputList::LogOutputNode * node,LogLevelType level)124 void LogOutputList::update_output_level(LogOutputList::LogOutputNode* node, LogLevelType level) {
125 add_output(node->_value, level);
126 wait_until_no_readers();
127 remove_output(node);
128 }
129