1 /*
2 * Copyright (c) 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
25 #include "precompiled.hpp"
26 #include "gc/serial/serialArguments.hpp"
27 #include "gc/shared/gcConfig.hpp"
28 #include "runtime/java.hpp"
29 #include "runtime/os.hpp"
30 #include "utilities/macros.hpp"
31 #if INCLUDE_ALL_GCS
32 #include "gc/parallel/parallelArguments.hpp"
33 #include "gc/cms/cmsArguments.hpp"
34 #include "gc/g1/g1Arguments.hpp"
35 #include "gc/epsilon/epsilonArguments.hpp"
36 #endif // INCLUDE_ALL_GCS
37
38 struct SupportedGC {
39 bool& _flag;
40 CollectedHeap::Name _name;
41 GCArguments& _arguments;
42
43 SupportedGC(bool& flag, CollectedHeap::Name name, GCArguments& arguments) :
44 _flag(flag), _name(name), _arguments(arguments) {}
45 };
46
47 static SerialArguments serialArguments;
48 #if INCLUDE_ALL_GCS
49 static ParallelArguments parallelArguments;
50 static CMSArguments cmsArguments;
51 static G1Arguments g1Arguments;
52 static EpsilonArguments epsilonArguments;
53 #endif // INCLUDE_ALL_GCS
54
55 // Table of supported GCs, for translating between command
56 // line flag, CollectedHeap::Name and GCArguments instance.
57 static const SupportedGC SupportedGCs[] = {
58 SupportedGC(UseSerialGC, CollectedHeap::Serial, serialArguments),
59 #if INCLUDE_ALL_GCS
60 SupportedGC(UseParallelGC, CollectedHeap::Parallel, parallelArguments),
61 SupportedGC(UseParallelOldGC, CollectedHeap::Parallel, parallelArguments),
62 SupportedGC(UseConcMarkSweepGC, CollectedHeap::CMS, cmsArguments),
63 SupportedGC(UseG1GC, CollectedHeap::G1, g1Arguments),
64 SupportedGC(UseEpsilonGC, CollectedHeap::Epsilon, epsilonArguments),
65 #endif // INCLUDE_ALL_GCS
66 };
67
68 GCArguments* GCConfig::_arguments = NULL;
69 bool GCConfig::_gc_selected_ergonomically = false;
70
71 void GCConfig::select_gc_ergonomically() {
72 #if INCLUDE_ALL_GCS
73 if (os::is_server_class_machine()) {
74 FLAG_SET_ERGO_IF_DEFAULT(bool, UseG1GC, true);
75 } else {
76 FLAG_SET_ERGO_IF_DEFAULT(bool, UseSerialGC, true);
77 }
78 #else
79 UNSUPPORTED_OPTION(UseG1GC);
80 UNSUPPORTED_OPTION(UseParallelGC);
81 UNSUPPORTED_OPTION(UseParallelOldGC);
82 UNSUPPORTED_OPTION(UseConcMarkSweepGC);
83 FLAG_SET_ERGO_IF_DEFAULT(bool, UseSerialGC, true);
84 #endif // INCLUDE_ALL_GCS
85 }
86
87 bool GCConfig::is_no_gc_selected() {
88 for (size_t i = 0; i < ARRAY_SIZE(SupportedGCs); i++) {
89 if (SupportedGCs[i]._flag) {
90 return false;
91 }
92 }
93
94 return true;
95 }
96
97 bool GCConfig::is_exactly_one_gc_selected() {
98 CollectedHeap::Name selected = CollectedHeap::None;
99
100 for (size_t i = 0; i < ARRAY_SIZE(SupportedGCs); i++) {
101 if (SupportedGCs[i]._flag) {
102 if (SupportedGCs[i]._name == selected || selected == CollectedHeap::None) {
103 // Selected
104 selected = SupportedGCs[i]._name;
105 } else {
106 // More than one selected
107 return false;
108 }
109 }
110 }
111
112 return selected != CollectedHeap::None;
113 }
114
115 GCArguments* GCConfig::select_gc() {
116 if (is_no_gc_selected()) {
117 // Try select GC ergonomically
118 select_gc_ergonomically();
119
120 if (is_no_gc_selected()) {
121 // Failed to select GC ergonomically
122 vm_exit_during_initialization("Garbage collector not selected "
123 "(default collector explicitly disabled)", NULL);
124 }
125
126 // Succeeded to select GC ergonomically
127 _gc_selected_ergonomically = true;
128 }
129
130 if (is_exactly_one_gc_selected()) {
131 // Exacly one GC selected
132 for (size_t i = 0; i < ARRAY_SIZE(SupportedGCs); i++) {
133 if (SupportedGCs[i]._flag) {
134 return &SupportedGCs[i]._arguments;
135 }
136 }
137 }
138
139 // More than one GC selected
140 vm_exit_during_initialization("Multiple garbage collectors selected", NULL);
141
142 return NULL;
143 }
144
145 void GCConfig::initialize() {
146 assert(_arguments == NULL, "Already initialized");
147 _arguments = select_gc();
148 }
149
150 bool GCConfig::is_gc_supported(CollectedHeap::Name name) {
151 for (size_t i = 0; i < ARRAY_SIZE(SupportedGCs); i++) {
152 if (SupportedGCs[i]._name == name) {
153 // Supported
154 return true;
155 }
156 }
157
158 // Not supported
159 return false;
160 }
161
162 bool GCConfig::is_gc_selected(CollectedHeap::Name name) {
163 for (size_t i = 0; i < ARRAY_SIZE(SupportedGCs); i++) {
164 if (SupportedGCs[i]._name == name && SupportedGCs[i]._flag) {
165 // Selected
166 return true;
167 }
168 }
169
170 // Not selected
171 return false;
172 }
173
174 bool GCConfig::is_gc_selected_ergonomically() {
175 return _gc_selected_ergonomically;
176 }
177
178 GCArguments* GCConfig::arguments() {
179 assert(_arguments != NULL, "Not initialized");
180 return _arguments;
181 }