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/serial/serialGC.hpp" 28 #include "runtime/globals.hpp" 29 #include "runtime/globals_extension.hpp" 30 #include "runtime/os.hpp" 31 #include "utilities/macros.hpp" 32 33 #if INCLUDE_ALL_GCS 34 #include "gc/parallel/parallelGC.hpp" 35 #include "gc/cms/cmsGC.hpp" 36 #include "gc/g1/g1GC.hpp" 37 #endif 38 39 GC* GC::_gc = NULL; 40 41 bool GC::gc_selected() { 42 #if INCLUDE_ALL_GCS 43 return UseSerialGC || UseParallelGC || UseParallelOldGC || UseConcMarkSweepGC || UseG1GC; 44 #else 45 return UseSerialGC; 46 #endif // INCLUDE_ALL_GCS 47 } 48 49 void GC::select_gc_ergonomically() { 50 #if INCLUDE_ALL_GCS 51 if (os::is_server_class_machine()) { 52 FLAG_SET_ERGO_IF_DEFAULT(bool, UseG1GC, true); 53 } else { 54 FLAG_SET_ERGO_IF_DEFAULT(bool, UseSerialGC, true); 55 } 56 #else 57 UNSUPPORTED_OPTION(UseG1GC); 58 UNSUPPORTED_OPTION(UseParallelGC); 59 UNSUPPORTED_OPTION(UseParallelOldGC); 60 UNSUPPORTED_OPTION(UseConcMarkSweepGC); 61 FLAG_SET_ERGO_IF_DEFAULT(bool, UseSerialGC, true); 62 #endif // INCLUDE_ALL_GCS 63 } 64 65 void GC::initialize_flags_global() { 66 #if INCLUDE_ALL_GCS 67 if (AssumeMP && !UseSerialGC) { 68 if (FLAG_IS_DEFAULT(ParallelGCThreads) && ParallelGCThreads == 1) { 69 warning("If the number of processors is expected to increase from one, then" 70 " you should configure the number of parallel GC threads appropriately" 71 " using -XX:ParallelGCThreads=N"); 72 } 73 } 74 if (MinHeapFreeRatio == 100) { 75 // Keeping the heap 100% free is hard ;-) so limit it to 99%. 76 FLAG_SET_ERGO(uintx, MinHeapFreeRatio, 99); 77 } 78 79 // If class unloading is disabled, also disable concurrent class unloading. 80 if (!ClassUnloading) { 81 FLAG_SET_CMDLINE(bool, CMSClassUnloadingEnabled, false); 82 FLAG_SET_CMDLINE(bool, ClassUnloadingWithConcurrentMark, false); 83 } 84 #endif // INCLUDE_ALL_GCS 85 } 86 87 jint GC::initialize() { 88 assert(_gc == NULL, "GC already created"); 89 90 select_gc(); 91 92 #if !INCLUDE_ALL_GCS 93 if (UseParallelGC || UseParallelOldGC) { 94 fatal("UseParallelGC not supported in this VM."); 95 } else if (UseG1GC) { 96 fatal("UseG1GC not supported in this VM."); 97 } else if (UseConcMarkSweepGC) { 98 fatal("UseConcMarkSweepGC not supported in this VM."); 99 #else 100 if (UseParallelGC || UseParallelOldGC) { 101 _gc = new ParallelGC(); 102 } else if (UseG1GC) { 103 _gc = new G1GC(); 104 } else if (UseConcMarkSweepGC) { 105 _gc = new CMSGC(); 106 #endif 107 } else if (UseSerialGC) { 108 _gc = new SerialGC(); 109 } else { 110 ShouldNotReachHere(); 111 } 112 return JNI_OK; 113 }