1 /*
2 * Copyright (c) 2018, 2020, 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/shared/gcConfig.hpp"
27 #include "runtime/globals.hpp"
28 #include "runtime/java.hpp"
29 #include "runtime/os.hpp"
30 #include "utilities/macros.hpp"
31 #if INCLUDE_EPSILONGC
32 #include "gc/epsilon/epsilonArguments.hpp"
33 #endif
34 #if INCLUDE_G1GC
35 #include "gc/g1/g1Arguments.hpp"
36 #endif
37 #if INCLUDE_PARALLELGC
38 #include "gc/parallel/parallelArguments.hpp"
39 #endif
40 #if INCLUDE_SERIALGC
41 #include "gc/serial/serialArguments.hpp"
42 #endif
43 #if INCLUDE_SHENANDOAHGC
44 #include "gc/shenandoah/shenandoahArguments.hpp"
45 #endif
46 #if INCLUDE_ZGC
47 #include "gc/z/zArguments.hpp"
48 #endif
49
50 struct IncludedGC {
51 bool& _flag;
52 CollectedHeap::Name _name;
53 GCArguments& _arguments;
54 const char* _hs_err_name;
55
56 IncludedGC(bool& flag, CollectedHeap::Name name, GCArguments& arguments, const char* hs_err_name) :
57 _flag(flag), _name(name), _arguments(arguments), _hs_err_name(hs_err_name) {}
58 };
59
60 EPSILONGC_ONLY(static EpsilonArguments epsilonArguments;)
61 G1GC_ONLY(static G1Arguments g1Arguments;)
62 PARALLELGC_ONLY(static ParallelArguments parallelArguments;)
63 SERIALGC_ONLY(static SerialArguments serialArguments;)
64 SHENANDOAHGC_ONLY(static ShenandoahArguments shenandoahArguments;)
65 ZGC_ONLY(static ZArguments zArguments;)
66
67 // Table of included GCs, for translating between command
68 // line flag, CollectedHeap::Name and GCArguments instance.
69 static const IncludedGC IncludedGCs[] = {
70 EPSILONGC_ONLY_ARG(IncludedGC(UseEpsilonGC, CollectedHeap::Epsilon, epsilonArguments, "epsilon gc"))
71 G1GC_ONLY_ARG(IncludedGC(UseG1GC, CollectedHeap::G1, g1Arguments, "g1 gc"))
72 PARALLELGC_ONLY_ARG(IncludedGC(UseParallelGC, CollectedHeap::Parallel, parallelArguments, "parallel gc"))
73 SERIALGC_ONLY_ARG(IncludedGC(UseSerialGC, CollectedHeap::Serial, serialArguments, "serial gc"))
74 SHENANDOAHGC_ONLY_ARG(IncludedGC(UseShenandoahGC, CollectedHeap::Shenandoah, shenandoahArguments, "shenandoah gc"))
75 ZGC_ONLY_ARG(IncludedGC(UseZGC, CollectedHeap::Z, zArguments, "z gc"))
76 };
77
78 #define FOR_EACH_INCLUDED_GC(var) \
79 for (const IncludedGC* var = &IncludedGCs[0]; var < &IncludedGCs[ARRAY_SIZE(IncludedGCs)]; var++)
80
81 #define FAIL_IF_SELECTED(option, enabled) \
82 if (option == enabled && FLAG_IS_CMDLINE(option)) { \
83 vm_exit_during_initialization(enabled ? \
84 "Option -XX:+" #option " not supported" : \
85 "Option -XX:-" #option " not supported"); \
86 }
87
88 GCArguments* GCConfig::_arguments = NULL;
89 bool GCConfig::_gc_selected_ergonomically = false;
90
91 void GCConfig::fail_if_non_included_gc_is_selected() {
92 NOT_EPSILONGC( FAIL_IF_SELECTED(UseEpsilonGC, true));
93 NOT_G1GC( FAIL_IF_SELECTED(UseG1GC, true));
94 NOT_PARALLELGC( FAIL_IF_SELECTED(UseParallelGC, true));
95 NOT_SERIALGC( FAIL_IF_SELECTED(UseSerialGC, true));
96 NOT_SHENANDOAHGC(FAIL_IF_SELECTED(UseShenandoahGC, true));
97 NOT_ZGC( FAIL_IF_SELECTED(UseZGC, true));
98 }
99
100 void GCConfig::select_gc_ergonomically() {
101 if (os::is_server_class_machine()) {
102 #if INCLUDE_G1GC
103 FLAG_SET_ERGO_IF_DEFAULT(UseG1GC, true);
104 #elif INCLUDE_PARALLELGC
105 FLAG_SET_ERGO_IF_DEFAULT(UseParallelGC, true);
106 #elif INCLUDE_SERIALGC
107 FLAG_SET_ERGO_IF_DEFAULT(UseSerialGC, true);
108 #endif
109 } else {
110 #if INCLUDE_SERIALGC
111 FLAG_SET_ERGO_IF_DEFAULT(UseSerialGC, true);
112 #endif
113 }
114 }
115
116 bool GCConfig::is_no_gc_selected() {
117 FOR_EACH_INCLUDED_GC(gc) {
118 if (gc->_flag) {
119 return false;
120 }
121 }
122
123 return true;
124 }
125
126 bool GCConfig::is_exactly_one_gc_selected() {
127 CollectedHeap::Name selected = CollectedHeap::None;
128
129 FOR_EACH_INCLUDED_GC(gc) {
130 if (gc->_flag) {
131 if (gc->_name == selected || selected == CollectedHeap::None) {
132 // Selected
133 selected = gc->_name;
134 } else {
135 // More than one selected
136 return false;
137 }
138 }
139 }
140
141 return selected != CollectedHeap::None;
142 }
143
144 GCArguments* GCConfig::select_gc() {
145 // Fail immediately if an unsupported GC is selected
146 fail_if_non_included_gc_is_selected();
147
148 if (is_no_gc_selected()) {
149 // Try select GC ergonomically
150 select_gc_ergonomically();
151
152 if (is_no_gc_selected()) {
153 // Failed to select GC ergonomically
154 vm_exit_during_initialization("Garbage collector not selected "
155 "(default collector explicitly disabled)", NULL);
156 }
157
158 // Succeeded to select GC ergonomically
159 _gc_selected_ergonomically = true;
160 }
161
162 if (!is_exactly_one_gc_selected()) {
163 // More than one GC selected
164 vm_exit_during_initialization("Multiple garbage collectors selected", NULL);
165 }
166
167 // Exactly one GC selected
168 FOR_EACH_INCLUDED_GC(gc) {
169 if (gc->_flag) {
170 return &gc->_arguments;
171 }
172 }
173
174 fatal("Should have found the selected GC");
175
176 return NULL;
177 }
178
179 void GCConfig::initialize() {
180 assert(_arguments == NULL, "Already initialized");
181 _arguments = select_gc();
182 }
183
184 bool GCConfig::is_gc_supported(CollectedHeap::Name name) {
185 FOR_EACH_INCLUDED_GC(gc) {
186 if (gc->_name == name && gc->_arguments.is_supported()) {
187 // Supported
188 return true;
189 }
190 }
191
192 // Not supported
193 return false;
194 }
195
196 bool GCConfig::is_gc_selected(CollectedHeap::Name name) {
197 FOR_EACH_INCLUDED_GC(gc) {
198 if (gc->_name == name && gc->_flag) {
199 // Selected
200 return true;
201 }
202 }
203
204 // Not selected
205 return false;
206 }
207
208 bool GCConfig::is_gc_selected_ergonomically() {
209 return _gc_selected_ergonomically;
210 }
211
212 const char* GCConfig::hs_err_name() {
213 if (is_exactly_one_gc_selected()) {
214 // Exacly one GC selected
215 FOR_EACH_INCLUDED_GC(gc) {
216 if (gc->_flag) {
217 return gc->_hs_err_name;
218 }
219 }
220 }
221
222 // Zero or more than one GC selected
223 return "unknown gc";
224 }
225
226 const char* GCConfig::hs_err_name(CollectedHeap::Name name) {
227 FOR_EACH_INCLUDED_GC(gc) {
228 if (gc->_name == name) {
229 return gc->_hs_err_name;
230 }
231 }
232 return "unknown gc";
233 }
234
235 GCArguments* GCConfig::arguments() {
236 assert(_arguments != NULL, "Not initialized");
237 return _arguments;
238 }