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/gc.hpp" 27 #include "gc/shared/gcFactory.hpp" 28 #include "gc/serial/serialGC.hpp" 29 #include "runtime/globals.hpp" 30 #include "runtime/globals_extension.hpp" 31 #include "runtime/java.hpp" 32 #include "runtime/os.hpp" 33 #include "utilities/macros.hpp" 34 35 #if INCLUDE_ALL_GCS 36 #include "gc/parallel/parallelGC.hpp" 37 #include "gc/cms/cmsGC.hpp" 38 #include "gc/g1/g1GC.hpp" 39 #endif 40 41 GC* GCFactory::_gc = NULL; 42 43 GC* GCFactory::gc() { 44 assert(_gc != NULL, "GC not yet created"); 45 return _gc; 46 } 47 48 bool GCFactory::is_initialized() { 49 return _gc != NULL; 50 } 51 52 bool GCFactory::gc_selected() { 53 #if INCLUDE_ALL_GCS 54 return UseSerialGC || UseParallelGC || UseParallelOldGC || UseConcMarkSweepGC || UseG1GC; 55 #else 56 return UseSerialGC; 57 #endif // INCLUDE_ALL_GCS 58 } 59 60 void GCFactory::select_gc() { 61 if (!gc_selected()) { 62 select_gc_ergonomically(); 63 if (!gc_selected()) { 64 vm_exit_during_initialization("Garbage collector not selected (default collector explicitly disabled)", NULL); 65 } 66 } 67 } 68 69 void GCFactory::select_gc_ergonomically() { 70 #if INCLUDE_ALL_GCS 71 if (os::is_server_class_machine()) { 72 FLAG_SET_ERGO_IF_DEFAULT(bool, UseG1GC, true); 73 } else { 74 FLAG_SET_ERGO_IF_DEFAULT(bool, UseSerialGC, true); 75 } 76 #else 77 UNSUPPORTED_OPTION(UseG1GC); 78 UNSUPPORTED_OPTION(UseParallelGC); 79 UNSUPPORTED_OPTION(UseParallelOldGC); 80 UNSUPPORTED_OPTION(UseConcMarkSweepGC); 81 FLAG_SET_ERGO_IF_DEFAULT(bool, UseSerialGC, true); 82 #endif // INCLUDE_ALL_GCS 83 } 84 85 void GCFactory::initialize_flags_global() { 86 #if INCLUDE_ALL_GCS 87 if (AssumeMP && !UseSerialGC) { 88 if (FLAG_IS_DEFAULT(ParallelGCThreads) && ParallelGCThreads == 1) { 89 warning("If the number of processors is expected to increase from one, then" 90 " you should configure the number of parallel GC threads appropriately" 91 " using -XX:ParallelGCThreads=N"); 92 } 93 } 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 jint GCFactory::initialize() { 108 assert(_gc == NULL, "GC already created"); 109 110 select_gc(); 111 112 #if !INCLUDE_ALL_GCS 113 if (UseParallelGC || UseParallelOldGC) { 114 fatal("UseParallelGC not supported in this VM."); 115 } else if (UseG1GC) { 116 fatal("UseG1GC not supported in this VM."); 117 } else if (UseConcMarkSweepGC) { 118 fatal("UseConcMarkSweepGC not supported in this VM."); 119 #else 120 if (UseParallelGC || UseParallelOldGC) { 121 _gc = new ParallelGC(); 122 } else if (UseG1GC) { 123 _gc = new G1GC(); 124 } else if (UseConcMarkSweepGC) { 125 _gc = new CMSGC(); 126 #endif 127 } else if (UseSerialGC) { 128 _gc = new SerialGC(); 129 } else { 130 ShouldNotReachHere(); 131 } 132 return JNI_OK; 133 }