1 /* 2 * Copyright (c) 1997, 2015, 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 #ifndef SHARE_VM_GC_SERIAL_MARKSWEEP_HPP 26 #define SHARE_VM_GC_SERIAL_MARKSWEEP_HPP 27 28 #include "gc/shared/collectedHeap.hpp" 29 #include "gc/shared/genOopClosures.hpp" 30 #include "gc/shared/taskqueue.hpp" 31 #include "memory/iterator.hpp" 32 #include "oops/markOop.hpp" 33 #include "oops/oop.hpp" 34 #include "runtime/timer.hpp" 35 #include "utilities/growableArray.hpp" 36 #include "utilities/stack.hpp" 37 38 class ReferenceProcessor; 39 class DataLayout; 40 class SerialOldTracer; 41 class STWGCTimer; 42 43 // MarkSweep takes care of global mark-compact garbage collection for a 44 // GenCollectedHeap using a four-phase pointer forwarding algorithm. All 45 // generations are assumed to support marking; those that can also support 46 // compaction. 47 // 48 // Class unloading will only occur when a full gc is invoked. 49 50 // declared at end 51 class PreservedMark; 52 class MarkAndPushClosure; 53 54 class MarkSweep : AllStatic { 55 // 56 // Inline closure decls 57 // 58 class FollowRootClosure: public OopsInGenClosure { 59 public: 60 virtual void do_oop(oop* p); 61 virtual void do_oop(narrowOop* p); 62 }; 63 64 class FollowStackClosure: public VoidClosure { 65 public: 66 virtual void do_void(); 67 }; 68 69 class AdjustPointerClosure: public OopsInGenClosure { 70 public: 71 template <typename T> void do_oop_nv(T* p); 72 virtual void do_oop(oop* p); 73 virtual void do_oop(narrowOop* p); 74 75 // This closure provides its own oop verification code. 76 debug_only(virtual bool should_verify_oops() { return false; }) 77 }; 78 79 // Used for java/lang/ref handling 80 class IsAliveClosure: public BoolObjectClosure { 81 public: 82 virtual bool do_object_b(oop p); 83 }; 84 85 class KeepAliveClosure: public OopClosure { 86 protected: 87 template <class T> void do_oop_work(T* p); 88 public: 89 virtual void do_oop(oop* p); 90 virtual void do_oop(narrowOop* p); 91 }; 92 93 // 94 // Friend decls 95 // 96 friend class AdjustPointerClosure; 97 friend class KeepAliveClosure; 98 friend class VM_MarkSweep; 99 friend void marksweep_init(); 100 101 // 102 // Vars 103 // 104 protected: 105 // Total invocations of a MarkSweep collection 106 static uint _total_invocations; 107 108 // Traversal stacks used during phase1 109 static Stack<oop, mtGC> _marking_stack; 110 static Stack<ObjArrayTask, mtGC> _objarray_stack; 111 112 // Space for storing/restoring mark word 113 static Stack<markOop, mtGC> _preserved_mark_stack; 114 static Stack<oop, mtGC> _preserved_oop_stack; 115 static size_t _preserved_count; 116 static size_t _preserved_count_max; 117 static PreservedMark* _preserved_marks; 118 119 // Reference processing (used in ...follow_contents) 120 static ReferenceProcessor* _ref_processor; 121 122 static STWGCTimer* _gc_timer; 123 static SerialOldTracer* _gc_tracer; 124 125 // Non public closures 126 static KeepAliveClosure keep_alive; 127 128 public: 129 // Public closures 130 static IsAliveClosure is_alive; 131 static FollowRootClosure follow_root_closure; 132 static MarkAndPushClosure mark_and_push_closure; 133 static FollowStackClosure follow_stack_closure; 134 static CLDToOopClosure follow_cld_closure; 135 static AdjustPointerClosure adjust_pointer_closure; 136 static CLDToOopClosure adjust_cld_closure; 137 138 // Accessors 139 static uint total_invocations() { return _total_invocations; } 140 141 // Reference Processing 142 static ReferenceProcessor* const ref_processor() { return _ref_processor; } 143 static void set_ref_processor(ReferenceProcessor* rp); 144 145 // Archive Object handling 146 static inline bool is_archive_object(oop object); 147 148 static STWGCTimer* gc_timer() { return _gc_timer; } 149 static SerialOldTracer* gc_tracer() { return _gc_tracer; } 150 151 static void preserve_mark(oop p, markOop mark); 152 // Save the mark word so it can be restored later 153 static void adjust_marks(); // Adjust the pointers in the preserved marks table 154 static void restore_marks(); // Restore the marks that we saved in preserve_mark 155 156 static int adjust_pointers(oop obj); 157 158 static void follow_stack(); // Empty marking stack. 159 160 static void follow_klass(Klass* klass); 161 162 static void follow_cld(ClassLoaderData* cld); 163 164 template <class T> static inline void adjust_pointer(T* p); 165 166 // Check mark and maybe push on marking stack 167 template <class T> static void mark_and_push(T* p); 168 169 private: 170 // Call backs for marking 171 static void mark_object(oop obj); 172 // Mark pointer and follow contents. Empty marking stack afterwards. 173 template <class T> static inline void follow_root(T* p); 174 175 static inline void push_objarray(oop obj, size_t index); 176 177 static void follow_object(oop obj); 178 179 static void follow_array(objArrayOop array); 180 181 static void follow_array_chunk(objArrayOop array, int index); 182 }; 183 184 class MarkAndPushClosure: public ExtendedOopClosure { 185 public: 186 template <typename T> void do_oop_nv(T* p); 187 virtual void do_oop(oop* p); 188 virtual void do_oop(narrowOop* p); 189 190 virtual bool do_metadata(); 191 bool do_metadata_nv(); 192 193 virtual void do_klass(Klass* k); 194 void do_klass_nv(Klass* k); 195 196 virtual void do_cld(ClassLoaderData* cld); 197 void do_cld_nv(ClassLoaderData* cld); 198 199 void set_ref_processor(ReferenceProcessor* rp) { 200 set_ref_processor_internal(rp); 201 } 202 }; 203 204 class PreservedMark VALUE_OBJ_CLASS_SPEC { 205 private: 206 oop _obj; 207 markOop _mark; 208 209 public: 210 void init(oop obj, markOop mark) { 211 _obj = obj; 212 _mark = mark; 213 } 214 215 void adjust_pointer(); 216 void restore(); 217 }; 218 219 #endif // SHARE_VM_GC_SERIAL_MARKSWEEP_HPP