1 /* 2 * Copyright (c) 2014, 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 "jfr/leakprofiler/chains/dfsClosure.hpp" 27 #include "jfr/leakprofiler/chains/edge.hpp" 28 #include "jfr/leakprofiler/chains/edgeStore.hpp" 29 #include "jfr/leakprofiler/utilities/granularTimer.hpp" 30 #include "jfr/leakprofiler/chains/bitset.hpp" 31 #include "jfr/leakprofiler/utilities/unifiedOop.hpp" 32 #include "jfr/leakprofiler/utilities/rootType.hpp" 33 #include "jfr/leakprofiler/chains/rootSetClosure.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 // max dfs depth should not exceed size of stack 41 static const size_t max_dfs_depth = 5000; 42 43 EdgeStore* DFSClosure::_edge_store = NULL; 44 BitSet* DFSClosure::_mark_bits = NULL; 45 const Edge* DFSClosure::_start_edge = NULL; 46 size_t DFSClosure::_max_depth = max_dfs_depth; 47 bool DFSClosure::_ignore_root_set = false; 48 49 DFSClosure::DFSClosure() : 50 _parent(NULL), 51 _reference(NULL), 52 _depth(0) { 53 } 54 55 DFSClosure::DFSClosure(DFSClosure* parent, size_t depth) : 56 _parent(parent), 57 _reference(NULL), 58 _depth(depth) { 59 } 60 61 void DFSClosure::find_leaks_from_edge(EdgeStore* edge_store, 62 BitSet* mark_bits, 63 const Edge* start_edge) { 64 assert(edge_store != NULL, "invariant"); 65 assert(mark_bits != NULL," invariant"); 66 assert(start_edge != NULL, "invariant"); 67 68 _edge_store = edge_store; 69 _mark_bits = mark_bits; 70 _start_edge = start_edge; 71 _ignore_root_set = false; 72 assert(_max_depth == max_dfs_depth, "invariant"); 73 74 // Depth-first search, starting from a BFS egde 75 DFSClosure dfs; 76 start_edge->pointee()->oop_iterate(&dfs); 77 } 78 79 void DFSClosure::find_leaks_from_root_set(EdgeStore* edge_store, 80 BitSet* mark_bits) { 81 assert(edge_store != NULL, "invariant"); 82 assert(mark_bits != NULL, "invariant"); 83 84 _edge_store = edge_store; 85 _mark_bits = mark_bits; 86 _start_edge = NULL; 87 88 // Mark root set, to avoid going sideways 89 _max_depth = 1; 90 _ignore_root_set = false; 91 DFSClosure dfs1; 92 RootSetClosure::process_roots(&dfs1); 93 94 // Depth-first search 95 _max_depth = max_dfs_depth; 96 _ignore_root_set = true; 97 assert(_start_edge == NULL, "invariant"); 98 DFSClosure dfs2; 99 RootSetClosure::process_roots(&dfs2); 100 } 101 102 void DFSClosure::closure_impl(const oop* reference, const oop pointee) { 103 assert(pointee != NULL, "invariant"); 104 assert(reference != NULL, "invariant"); 105 106 if (GranularTimer::is_finished()) { 107 return; 108 } 109 if (_depth == 0 && _ignore_root_set) { 110 // Root set is already marked, but we want 111 // to continue, so skip is_marked check. 112 assert(_mark_bits->is_marked(pointee), "invariant"); 113 } else { 114 if (_mark_bits->is_marked(pointee)) { 115 return; 116 } 117 } 118 119 _reference = reference; 120 _mark_bits->mark_obj(pointee); 121 assert(_mark_bits->is_marked(pointee), "invariant"); 122 123 // is the pointee a sample object? 124 if (NULL == pointee->mark()) { 125 add_chain(); 126 } 127 128 assert(_max_depth >= 1, "invariant"); 129 if (_depth < _max_depth - 1) { 130 DFSClosure next_level(this, _depth + 1); 131 pointee->oop_iterate(&next_level); 132 } 133 } 134 135 void DFSClosure::add_chain() { 136 const size_t length = _start_edge == NULL ? _depth + 1 : 137 _start_edge->distance_to_root() + 1 + _depth + 1; 138 139 ResourceMark rm; 140 Edge* const chain = NEW_RESOURCE_ARRAY(Edge, length); 141 size_t idx = 0; 142 143 // aggregate from depth-first search 144 const DFSClosure* c = this; 145 while (c != NULL) { 146 chain[idx++] = Edge(NULL, c->reference()); 147 c = c->parent(); 148 } 149 150 assert(idx == _depth + 1, "invariant"); 151 152 // aggregate from breadth-first search 153 const Edge* current = _start_edge; 154 while (current != NULL) { 155 chain[idx++] = Edge(NULL, current->reference()); 156 current = current->parent(); 157 } 158 assert(idx == length, "invariant"); 159 _edge_store->add_chain(chain, length); 160 } 161 162 void DFSClosure::do_oop(oop* ref) { 163 assert(ref != NULL, "invariant"); 164 assert(is_aligned(ref, HeapWordSize), "invariant"); 165 const oop pointee = *ref; 166 if (pointee != NULL) { 167 closure_impl(ref, pointee); 168 } 169 } 170 171 void DFSClosure::do_oop(narrowOop* ref) { 172 assert(ref != NULL, "invariant"); 173 assert(is_aligned(ref, sizeof(narrowOop)), "invariant"); 174 const oop pointee = RawAccess<>::oop_load(ref); 175 if (pointee != NULL) { 176 closure_impl(UnifiedOop::encode(ref), pointee); 177 } 178 }