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/shared/gcConfig.hpp"
  27 #include "runtime/globals_extension.hpp"
  28 #include "runtime/java.hpp"
  29 #include "runtime/os.hpp"
  30 #include "utilities/macros.hpp"
  31 #if INCLUDE_CMSGC
  32 #include "gc/cms/cmsArguments.hpp"
  33 #endif
  34 #if INCLUDE_EPSILONGC
  35 #include "gc/epsilon/epsilonArguments.hpp"
  36 #endif
  37 #if INCLUDE_G1GC
  38 #include "gc/g1/g1Arguments.hpp"
  39 #endif
  40 #if INCLUDE_PARALLELGC
  41 #include "gc/parallel/parallelArguments.hpp"
  42 #endif
  43 #if INCLUDE_SERIALGC
  44 #include "gc/serial/serialArguments.hpp"
  45 #endif
  46 #if INCLUDE_SHENANDOAHGC
  47 #include "gc/shenandoah/shenandoahArguments.hpp"
  48 #endif
  49 #if INCLUDE_ZGC
  50 #include "gc/z/zArguments.hpp"
  51 #endif
  52 
  53 struct SupportedGC {
  54   bool&               _flag;
  55   CollectedHeap::Name _name;
  56   GCArguments&        _arguments;
  57   const char*         _hs_err_name;
  58 
  59   SupportedGC(bool& flag, CollectedHeap::Name name, GCArguments& arguments, const char* hs_err_name) :
  60       _flag(flag), _name(name), _arguments(arguments), _hs_err_name(hs_err_name) {}
  61 };
  62 
  63        CMSGC_ONLY(static CMSArguments      cmsArguments;)
  64    EPSILONGC_ONLY(static EpsilonArguments  epsilonArguments;)
  65         G1GC_ONLY(static G1Arguments       g1Arguments;)
  66   PARALLELGC_ONLY(static ParallelArguments parallelArguments;)
  67     SERIALGC_ONLY(static SerialArguments   serialArguments;)
  68 SHENANDOAHGC_ONLY(static ShenandoahArguments shenandoahArguments;)
  69          ZGC_ONLY(static ZArguments        zArguments;)
  70 
  71 // Table of supported GCs, for translating between command
  72 // line flag, CollectedHeap::Name and GCArguments instance.
  73 static const SupportedGC SupportedGCs[] = {
  74        CMSGC_ONLY_ARG(SupportedGC(UseConcMarkSweepGC, CollectedHeap::CMS,        cmsArguments,        "concurrent mark sweep gc"))
  75    EPSILONGC_ONLY_ARG(SupportedGC(UseEpsilonGC,       CollectedHeap::Epsilon,    epsilonArguments,    "epsilon gc"))
  76         G1GC_ONLY_ARG(SupportedGC(UseG1GC,            CollectedHeap::G1,         g1Arguments,         "g1 gc"))
  77   PARALLELGC_ONLY_ARG(SupportedGC(UseParallelGC,      CollectedHeap::Parallel,   parallelArguments,   "parallel gc"))
  78   PARALLELGC_ONLY_ARG(SupportedGC(UseParallelOldGC,   CollectedHeap::Parallel,   parallelArguments,   "parallel gc"))
  79     SERIALGC_ONLY_ARG(SupportedGC(UseSerialGC,        CollectedHeap::Serial,     serialArguments,     "serial gc"))
  80 SHENANDOAHGC_ONLY_ARG(SupportedGC(UseShenandoahGC,    CollectedHeap::Shenandoah, shenandoahArguments, "shenandoah gc"))
  81          ZGC_ONLY_ARG(SupportedGC(UseZGC,             CollectedHeap::Z,          zArguments,          "z gc"))
  82 };
  83 
  84 #define FOR_EACH_SUPPORTED_GC(var)                                          \
  85   for (const SupportedGC* var = &SupportedGCs[0]; var < &SupportedGCs[ARRAY_SIZE(SupportedGCs)]; var++)
  86 
  87 #define FAIL_IF_SELECTED(option, enabled)                                   \
  88   if (option == enabled && FLAG_IS_CMDLINE(option)) {                       \
  89     vm_exit_during_initialization(enabled ?                                 \
  90                                   "Option -XX:+" #option " not supported" : \
  91                                   "Option -XX:-" #option " not supported"); \
  92   }
  93 
  94 GCArguments* GCConfig::_arguments = NULL;
  95 bool GCConfig::_gc_selected_ergonomically = false;
  96 
  97 void GCConfig::fail_if_unsupported_gc_is_selected() {
  98   NOT_CMSGC(       FAIL_IF_SELECTED(UseConcMarkSweepGC, true));
  99   NOT_EPSILONGC(   FAIL_IF_SELECTED(UseEpsilonGC,       true));
 100   NOT_G1GC(        FAIL_IF_SELECTED(UseG1GC,            true));
 101   NOT_PARALLELGC(  FAIL_IF_SELECTED(UseParallelGC,      true));
 102   NOT_PARALLELGC(  FAIL_IF_SELECTED(UseParallelOldGC,   true));
 103   NOT_SERIALGC(    FAIL_IF_SELECTED(UseSerialGC,        true));
 104   NOT_SERIALGC(    FAIL_IF_SELECTED(UseParallelOldGC,   false));
 105   NOT_SHENANDOAHGC(FAIL_IF_SELECTED(UseShenandoahGC,    true));
 106   NOT_ZGC(         FAIL_IF_SELECTED(UseZGC,             true));
 107 }
 108 
 109 void GCConfig::select_gc_ergonomically() {
 110   if (os::is_server_class_machine()) {
 111 #if INCLUDE_G1GC
 112     FLAG_SET_ERGO_IF_DEFAULT(bool, UseG1GC, true);
 113 #elif INCLUDE_PARALLELGC
 114     FLAG_SET_ERGO_IF_DEFAULT(bool, UseParallelGC, true);
 115 #elif INCLUDE_SERIALGC
 116     FLAG_SET_ERGO_IF_DEFAULT(bool, UseSerialGC, true);
 117 #endif
 118   } else {
 119 #if INCLUDE_SERIALGC
 120     FLAG_SET_ERGO_IF_DEFAULT(bool, UseSerialGC, true);
 121 #endif
 122   }
 123 }
 124 
 125 bool GCConfig::is_no_gc_selected() {
 126   FOR_EACH_SUPPORTED_GC(gc) {
 127     if (gc->_flag) {
 128       return false;
 129     }
 130   }
 131 
 132   return true;
 133 }
 134 
 135 bool GCConfig::is_exactly_one_gc_selected() {
 136   CollectedHeap::Name selected = CollectedHeap::None;
 137 
 138   FOR_EACH_SUPPORTED_GC(gc) {
 139     if (gc->_flag) {
 140       if (gc->_name == selected || selected == CollectedHeap::None) {
 141         // Selected
 142         selected = gc->_name;
 143       } else {
 144         // More than one selected
 145         return false;
 146       }
 147     }
 148   }
 149 
 150   return selected != CollectedHeap::None;
 151 }
 152 
 153 GCArguments* GCConfig::select_gc() {
 154   // Fail immediately if an unsupported GC is selected
 155   fail_if_unsupported_gc_is_selected();
 156 
 157   if (is_no_gc_selected()) {
 158     // Try select GC ergonomically
 159     select_gc_ergonomically();
 160 
 161     if (is_no_gc_selected()) {
 162       // Failed to select GC ergonomically
 163       vm_exit_during_initialization("Garbage collector not selected "
 164                                     "(default collector explicitly disabled)", NULL);
 165     }
 166 
 167     // Succeeded to select GC ergonomically
 168     _gc_selected_ergonomically = true;
 169   }
 170 
 171   if (!is_exactly_one_gc_selected()) {
 172     // More than one GC selected
 173     vm_exit_during_initialization("Multiple garbage collectors selected", NULL);
 174   }
 175 
 176   // Exactly one GC selected
 177   FOR_EACH_SUPPORTED_GC(gc) {
 178     if (gc->_flag) {
 179       return &gc->_arguments;
 180     }
 181   }
 182 
 183   fatal("Should have found the selected GC");
 184 
 185   return NULL;
 186 }
 187 
 188 void GCConfig::initialize() {
 189   assert(_arguments == NULL, "Already initialized");
 190   _arguments = select_gc();
 191 }
 192 
 193 bool GCConfig::is_gc_supported(CollectedHeap::Name name) {
 194   FOR_EACH_SUPPORTED_GC(gc) {
 195     if (gc->_name == name) {
 196       // Supported
 197       return true;
 198     }
 199   }
 200 
 201   // Not supported
 202   return false;
 203 }
 204 
 205 bool GCConfig::is_gc_selected(CollectedHeap::Name name) {
 206   FOR_EACH_SUPPORTED_GC(gc) {
 207     if (gc->_name == name && gc->_flag) {
 208       // Selected
 209       return true;
 210     }
 211   }
 212 
 213   // Not selected
 214   return false;
 215 }
 216 
 217 bool GCConfig::is_gc_selected_ergonomically() {
 218   return _gc_selected_ergonomically;
 219 }
 220 
 221 const char* GCConfig::hs_err_name() {
 222   if (is_exactly_one_gc_selected()) {
 223     // Exacly one GC selected
 224     FOR_EACH_SUPPORTED_GC(gc) {
 225       if (gc->_flag) {
 226         return gc->_hs_err_name;
 227       }
 228     }
 229   }
 230 
 231   // Zero or more than one GC selected
 232   return "unknown gc";
 233 }
 234 
 235 const char* GCConfig::hs_err_name(CollectedHeap::Name name) {
 236   FOR_EACH_SUPPORTED_GC(gc) {
 237     if (gc->_name == name) {
 238       return gc->_hs_err_name;
 239     }
 240   }
 241   return "unknown gc";
 242 }
 243 
 244 GCArguments* GCConfig::arguments() {
 245   assert(_arguments != NULL, "Not initialized");
 246   return _arguments;
 247 }