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