1 /* 2 * Copyright (c) 2017, 2018, 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 #include "precompiled.hpp" 26 #include "classfile/classLoaderDataGraph.hpp" 27 #include "jfr/leakprofiler/utilities/saveRestore.hpp" 28 #include "oops/oop.inline.hpp" 29 30 MarkOopContext::MarkOopContext() : _obj(NULL), _mark_oop(NULL) {} 31 32 MarkOopContext::MarkOopContext(const oop obj) : _obj(obj), _mark_oop(obj->mark()) { 33 assert(_obj->mark() == _mark_oop, "invariant"); 34 // now we will "poison" the mark word of the object 35 // to the intermediate monitor INFLATING state. 36 // This is an "impossible" state during a safepoint, 37 // hence we will use it to quickly identify objects 38 // during the reachability search from gc roots. 39 assert(NULL == markOopDesc::INFLATING(), "invariant"); 40 _obj->set_mark(markOopDesc::INFLATING()); 41 assert(NULL == obj->mark(), "invariant"); 42 } 43 44 MarkOopContext::~MarkOopContext() { 45 if (_obj != NULL) { 46 _obj->set_mark(_mark_oop); 47 assert(_obj->mark() == _mark_oop, "invariant"); 48 } 49 } 50 51 MarkOopContext::MarkOopContext(const MarkOopContext& rhs) : _obj(NULL), _mark_oop(NULL) { 52 swap(const_cast<MarkOopContext&>(rhs)); 53 } 54 55 void MarkOopContext::operator=(MarkOopContext rhs) { 56 swap(rhs); 57 } 58 59 void MarkOopContext::swap(MarkOopContext& rhs) { 60 oop temp_obj = rhs._obj; 61 markOop temp_mark_oop = rhs._mark_oop; 62 rhs._obj = _obj; 63 rhs._mark_oop = _mark_oop; 64 _obj = temp_obj; 65 _mark_oop = temp_mark_oop; 66 } 67 68 CLDClaimContext::CLDClaimContext() : _cld(NULL) {} 69 70 CLDClaimContext::CLDClaimContext(ClassLoaderData* cld) : _cld(cld) { 71 assert(_cld->claimed(), "invariant"); 72 _cld->clear_claim(); 73 } 74 75 CLDClaimContext::~CLDClaimContext() { 76 if (_cld != NULL) { 77 _cld->try_claim(ClassLoaderData::_claim_strong); 78 assert(_cld->claimed(), "invariant"); 79 } 80 } 81 82 CLDClaimContext::CLDClaimContext(const CLDClaimContext& rhs) : _cld(NULL) { 83 swap(const_cast<CLDClaimContext&>(rhs)); 84 } 85 86 void CLDClaimContext::operator=(CLDClaimContext rhs) { 87 swap(rhs); 88 } 89 90 void CLDClaimContext::swap(CLDClaimContext& rhs) { 91 ClassLoaderData* temp_cld = rhs._cld; 92 rhs._cld = _cld; 93 _cld = temp_cld; 94 } 95 96 CLDClaimStateClosure::CLDClaimStateClosure() : CLDClosure(), _state() {} 97 98 void CLDClaimStateClosure::do_cld(ClassLoaderData* cld) { 99 assert(cld != NULL, "invariant"); 100 if (cld->claimed()) { 101 _state.save(cld); 102 } 103 } 104 105 SaveRestoreCLDClaimBits::SaveRestoreCLDClaimBits() : _claim_state_closure() { 106 // interferes with GC, so walk all oops that GC would. 107 ClassLoaderDataGraph::cld_do(&_claim_state_closure); 108 } 109 110 SaveRestoreCLDClaimBits::~SaveRestoreCLDClaimBits() { 111 ClassLoaderDataGraph::clear_claimed_marks(); 112 }