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 // initialize 39 virtual bool init() = 0; 40 // clean-up 41 virtual void done() = 0; 42 43 // mark an object if not yet marked. 44 // return true if the oop is marked by this call 45 virtual bool mark(oop o) = 0; 46 // check if the object has been 47 virtual bool marked(oop o) = 0; 48 49 bool needs_reset() const { return _needs_reset; } 50 void set_needs_reset(bool v) { _needs_reset = v; } 51 }; 52 53 // Default implementation 54 class DefaultObjectMarker : public ObjectMarker { 55 private: 56 // saved headers 57 GrowableArray<oop>* _saved_oop_stack; 58 GrowableArray<markWord>* _saved_mark_stack; 59 60 public: 61 DefaultObjectMarker(); 62 bool init(); 63 void done(); 64 65 bool mark(oop o); 66 bool marked(oop o); 67 }; 68 69 #endif // SHARE_GC_SHARED_OBJECTMARKER_HPP