1 /* 2 * Copyright (c) 2020, 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_GC_SHARED_OBJECTMARKER_HPP 26 #define SHARE_GC_SHARED_OBJECTMARKER_HPP 27 28 #include "memory/allocation.hpp" 29 #include "oops/markWord.hpp" 30 #include "utilities/growableArray.hpp" 31 32 // ObjectMarker is used to support JVMTI for marking objects when walking the 33 // heap. 34 class ObjectMarker : public CHeapObj<mtInternal> { 35 protected: 36 bool _needs_reset; 37 public: 38 virtual bool init() = 0; // initialize 39 virtual void done() = 0; // clean-up 40 41 // mark an object if not yet marked. 42 // return true if the oop is marked by this call 43 virtual bool mark(oop o) = 0; 44 virtual bool visited(oop o) = 0; // check if object has been visited 45 46 bool needs_reset() const { return _needs_reset; } 47 void set_needs_reset(bool v) { _needs_reset = v; } 48 }; 49 50 // ObjectMarker provides the mark and visited functions 51 class DefaultObjectMarker : public ObjectMarker { 52 private: 53 // saved headers 54 GrowableArray<oop>* _saved_oop_stack; 55 GrowableArray<markWord>* _saved_mark_stack; 56 57 public: 58 DefaultObjectMarker(); 59 bool init(); 60 void done(); 61 62 bool mark(oop o); 63 bool visited(oop o); 64 }; 65 66 #endif // SHARE_GC_SHARED_OBJECTMARKER_HPP