1 /*
   2  * Copyright (c) 2017, Red Hat, Inc. and/or its affiliates.
   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/gcArguments.hpp"
  27 #include "gc/serial/serialArguments.hpp"
  28 #include "logging/log.hpp"
  29 #include "memory/allocation.inline.hpp"
  30 #include "runtime/arguments.hpp"
  31 #include "runtime/globals.hpp"
  32 #include "runtime/globals_extension.hpp"
  33 #include "runtime/java.hpp"
  34 #include "runtime/os.hpp"
  35 #include "utilities/defaultStream.hpp"
  36 #include "utilities/macros.hpp"
  37 
  38 #if INCLUDE_ALL_GCS
  39 #include "gc/parallel/parallelArguments.hpp"
  40 #include "gc/cms/cmsArguments.hpp"
  41 #include "gc/g1/g1Arguments.hpp"
  42 #endif
  43 
  44 GCArguments* GCArguments::_instance = NULL;
  45 
  46 GCArguments* GCArguments::arguments() {
  47   assert(is_initialized(), "Heap factory not yet created");
  48   return _instance;
  49 }
  50 
  51 bool GCArguments::is_initialized() {
  52   return _instance != NULL;
  53 }
  54 
  55 bool GCArguments::gc_selected() {
  56 #if INCLUDE_ALL_GCS
  57   return UseSerialGC || UseParallelGC || UseParallelOldGC || UseConcMarkSweepGC || UseG1GC;
  58 #else
  59   return UseSerialGC;
  60 #endif // INCLUDE_ALL_GCS
  61 }
  62 
  63 void GCArguments::select_gc() {
  64   if (!gc_selected()) {
  65     select_gc_ergonomically();
  66     if (!gc_selected()) {
  67       vm_exit_during_initialization("Garbage collector not selected (default collector explicitly disabled)", NULL);
  68     }
  69   }
  70 }
  71 
  72 void GCArguments::select_gc_ergonomically() {
  73 #if INCLUDE_ALL_GCS
  74   if (os::is_server_class_machine()) {
  75     FLAG_SET_ERGO_IF_DEFAULT(bool, UseG1GC, true);
  76   } else {
  77     FLAG_SET_ERGO_IF_DEFAULT(bool, UseSerialGC, true);
  78   }
  79 #else
  80   UNSUPPORTED_OPTION(UseG1GC);
  81   UNSUPPORTED_OPTION(UseParallelGC);
  82   UNSUPPORTED_OPTION(UseParallelOldGC);
  83   UNSUPPORTED_OPTION(UseConcMarkSweepGC);
  84   FLAG_SET_ERGO_IF_DEFAULT(bool, UseSerialGC, true);
  85 #endif // INCLUDE_ALL_GCS
  86 }
  87 
  88 void GCArguments::parse_verification_type(const char* type) {
  89   log_warning(gc, verify)("VerifyGCType is not supported by this collector.");
  90 }
  91 
  92 void GCArguments::initialize_flags() {
  93 #if INCLUDE_ALL_GCS
  94   if (MinHeapFreeRatio == 100) {
  95     // Keeping the heap 100% free is hard ;-) so limit it to 99%.
  96     FLAG_SET_ERGO(uintx, MinHeapFreeRatio, 99);
  97   }
  98 
  99   // If class unloading is disabled, also disable concurrent class unloading.
 100   if (!ClassUnloading) {
 101     FLAG_SET_CMDLINE(bool, CMSClassUnloadingEnabled, false);
 102     FLAG_SET_CMDLINE(bool, ClassUnloadingWithConcurrentMark, false);
 103   }
 104 #endif // INCLUDE_ALL_GCS
 105 }
 106 
 107 void GCArguments::post_heap_initialize() {
 108   if (strlen(VerifyGCType) > 0) {
 109     const char delimiter[] = " ,\n";
 110     size_t length = strlen(VerifyGCType);
 111     char* type_list = NEW_C_HEAP_ARRAY(char, length + 1, mtInternal);
 112     strncpy(type_list, VerifyGCType, length + 1);
 113     char* token = strtok(type_list, delimiter);
 114     while (token != NULL) {
 115       parse_verification_type(token);
 116       token = strtok(NULL, delimiter);
 117     }
 118     FREE_C_HEAP_ARRAY(char, type_list);
 119   }
 120 }
 121 
 122 jint GCArguments::initialize() {
 123   assert(!is_initialized(), "GC arguments already initialized");
 124 
 125   select_gc();
 126 
 127 #if !INCLUDE_ALL_GCS
 128   if (UseParallelGC || UseParallelOldGC) {
 129     jio_fprintf(defaultStream::error_stream(), "UseParallelGC not supported in this VM.\n");
 130     return JNI_ERR;
 131   } else if (UseG1GC) {
 132     jio_fprintf(defaultStream::error_stream(), "UseG1GC not supported in this VM.\n");
 133     return JNI_ERR;
 134   } else if (UseConcMarkSweepGC) {
 135     jio_fprintf(defaultStream::error_stream(), "UseConcMarkSweepGC not supported in this VM.\n");
 136     return JNI_ERR;
 137 #else
 138   if (UseParallelGC || UseParallelOldGC) {
 139     _instance = new ParallelArguments();
 140   } else if (UseG1GC) {
 141     _instance = new G1Arguments();
 142   } else if (UseConcMarkSweepGC) {
 143     _instance = new CMSArguments();
 144 #endif
 145   } else if (UseSerialGC) {
 146     _instance = new SerialArguments();
 147   } else {
 148     ShouldNotReachHere();
 149   }
 150   return JNI_OK;
 151 }