1 /* 2 * Copyright (c) 2014, 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 #include "precompiled.hpp" 26 #include "jfr/leakprofiler/chains/bitset.inline.hpp" 27 #include "jfr/leakprofiler/chains/dfsClosure.hpp" 28 #include "jfr/leakprofiler/chains/edge.hpp" 29 #include "jfr/leakprofiler/chains/edgeStore.hpp" 30 #include "jfr/leakprofiler/chains/rootSetClosure.hpp" 31 #include "jfr/leakprofiler/utilities/granularTimer.hpp" 32 #include "jfr/leakprofiler/utilities/rootType.hpp" 33 #include "jfr/leakprofiler/utilities/unifiedOopRef.inline.hpp" 34 #include "memory/iterator.inline.hpp" 35 #include "memory/resourceArea.hpp" 36 #include "oops/access.inline.hpp" 37 #include "oops/oop.inline.hpp" 38 #include "utilities/align.hpp" 39 40 UnifiedOopRef DFSClosure::_reference_stack[max_dfs_depth]; 41 42 void DFSClosure::find_leaks_from_edge(EdgeStore* edge_store, 43 BitSet* mark_bits, 44 const Edge* start_edge) { 45 assert(edge_store != NULL, "invariant"); 46 assert(mark_bits != NULL," invariant"); 47 assert(start_edge != NULL, "invariant"); 48 49 // Depth-first search, starting from a BFS egde 50 DFSClosure dfs(edge_store, mark_bits, start_edge); 51 start_edge->pointee()->oop_iterate(&dfs); 52 } 53 54 void DFSClosure::find_leaks_from_root_set(EdgeStore* edge_store, 55 BitSet* mark_bits) { 56 assert(edge_store != NULL, "invariant"); 57 assert(mark_bits != NULL, "invariant"); 58 59 // Mark root set, to avoid going sideways 60 DFSClosure dfs(edge_store, mark_bits, NULL); 61 dfs._max_depth = 1; 62 RootSetClosure<DFSClosure> rs(&dfs); 63 rs.process(); 64 65 // Depth-first search 66 dfs._max_depth = max_dfs_depth; 67 dfs._ignore_root_set = true; 68 rs.process(); 69 } 70 71 DFSClosure::DFSClosure(EdgeStore* edge_store, BitSet* mark_bits, const Edge* start_edge) 72 :_edge_store(edge_store), _mark_bits(mark_bits), _start_edge(start_edge), 73 _max_depth(max_dfs_depth), _depth(0), _ignore_root_set(false) { 74 } 75 76 void DFSClosure::closure_impl(UnifiedOopRef reference, const oop pointee) { 77 assert(pointee != NULL, "invariant"); 78 assert(!reference.is_null(), "invariant"); 79 80 if (GranularTimer::is_finished()) { 81 return; 82 } 83 if (_depth == 0 && _ignore_root_set) { 84 // Root set is already marked, but we want 85 // to continue, so skip is_marked check. 86 assert(_mark_bits->is_marked(pointee), "invariant"); 87 } else { 88 if (_mark_bits->is_marked(pointee)) { 89 return; 90 } 91 } 92 _reference_stack[_depth] = reference; 93 _mark_bits->mark_obj(pointee); 94 assert(_mark_bits->is_marked(pointee), "invariant"); 95 96 // is the pointee a sample object? 97 if (pointee->mark().is_marked()) { 98 add_chain(); 99 } 100 101 assert(_max_depth >= 1, "invariant"); 102 if (_depth < _max_depth - 1) { 103 _depth++; 104 pointee->oop_iterate(this); 105 assert(_depth > 0, "invariant"); 106 _depth--; 107 } 108 } 109 110 void DFSClosure::add_chain() { 111 const size_t array_length = _depth + 2; 112 113 ResourceMark rm; 114 Edge* const chain = NEW_RESOURCE_ARRAY(Edge, array_length); 115 size_t idx = 0; 116 117 // aggregate from depth-first search 118 for (size_t i = 0; i <= _depth; i++) { 119 const size_t next = idx + 1; 120 const size_t depth = _depth - i; 121 chain[idx++] = Edge(&chain[next], _reference_stack[depth]); 122 } 123 assert(_depth + 1 == idx, "invariant"); 124 assert(array_length == idx + 1, "invariant"); 125 126 // aggregate from breadth-first search 127 if (_start_edge != NULL) { 128 chain[idx++] = *_start_edge; 129 } else { 130 chain[idx - 1] = Edge(NULL, chain[idx - 1].reference()); 131 } 132 _edge_store->put_chain(chain, idx + (_start_edge != NULL ? _start_edge->distance_to_root() : 0)); 133 } 134 135 void DFSClosure::do_oop(oop* ref) { 136 assert(ref != NULL, "invariant"); 137 assert(is_aligned(ref, HeapWordSize), "invariant"); 138 const oop pointee = HeapAccess<AS_NO_KEEPALIVE>::oop_load(ref); 139 if (pointee != NULL) { 140 closure_impl(UnifiedOopRef::encode_in_heap(ref), pointee); 141 } 142 } 143 144 void DFSClosure::do_oop(narrowOop* ref) { 145 assert(ref != NULL, "invariant"); 146 assert(is_aligned(ref, sizeof(narrowOop)), "invariant"); 147 const oop pointee = HeapAccess<AS_NO_KEEPALIVE>::oop_load(ref); 148 if (pointee != NULL) { 149 closure_impl(UnifiedOopRef::encode_in_heap(ref), pointee); 150 } 151 } 152 153 void DFSClosure::do_root(UnifiedOopRef ref) { 154 assert(!ref.is_null(), "invariant"); 155 const oop pointee = ref.dereference(); 156 assert(pointee != NULL, "invariant"); 157 closure_impl(ref, pointee); 158 }