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 #ifndef SHARE_VM_LEAKPROFILER_CHAINS_EDGESTORE_HPP
26 #define SHARE_VM_LEAKPROFILER_CHAINS_EDGESTORE_HPP
27
28 #include "jfr/leakprofiler/chains/edge.hpp"
29 #include "jfr/utilities/jfrHashtable.hpp"
30 #include "memory/allocation.hpp"
31
32 typedef u8 traceid;
33
34 class StoredEdge : public Edge {
35 private:
36 mutable traceid _gc_root_id;
37 size_t _skip_length;
38
39 public:
40 StoredEdge();
41 StoredEdge(const Edge* parent, const oop* reference);
42 StoredEdge(const Edge& edge);
43 StoredEdge(const StoredEdge& edge);
44 void operator=(const StoredEdge& edge);
45
46 traceid gc_root_id() const { return _gc_root_id; }
47 void set_gc_root_id(traceid root_id) const { _gc_root_id = root_id; }
48
49 bool is_skip_edge() const { return _skip_length != 0; }
50 size_t skip_length() const { return _skip_length; }
51 void set_skip_length(size_t length) { _skip_length = length; }
52
53 void set_parent(const Edge* edge) { this->_parent = edge; }
54
55 StoredEdge* parent() const {
56 return const_cast<StoredEdge*>(static_cast<const StoredEdge*>(Edge::parent()));
57 }
58 };
59
60 class EdgeStore : public CHeapObj<mtTracing> {
61 typedef HashTableHost<StoredEdge, traceid, Entry, EdgeStore> EdgeHashTable;
62 typedef EdgeHashTable::HashEntry EdgeEntry;
63 template <typename,
64 typename,
65 template<typename, typename> class,
66 typename,
67 size_t>
68 friend class HashTableHost;
69 friend class EventEmitter;
70 friend class ObjectSampleWriter;
71 friend class ObjectSampleCheckpoint;
72 private:
73 static traceid _edge_id_counter;
74 EdgeHashTable* _edges;
75
76 // Hash table callbacks
77 void assign_id(EdgeEntry* entry);
78 bool equals(const Edge& query, uintptr_t hash, const EdgeEntry* entry);
79
80 StoredEdge* get(const oop* reference) const;
81 StoredEdge* put(const oop* reference);
82 traceid gc_root_id(const Edge* edge) const;
83
84 bool put_edges(StoredEdge** previous, const Edge** current, size_t length);
85 bool put_skip_edge(StoredEdge** previous, const Edge** current, size_t distance_to_root);
86 void put_chain_epilogue(StoredEdge* leak_context_edge, const Edge* root) const;
87
88 StoredEdge* associate_leak_context_with_candidate(const Edge* edge);
89 void store_gc_root_id_in_leak_context_edge(StoredEdge* leak_context_edge, const Edge* root) const;
90 StoredEdge* link_new_edge(StoredEdge** previous, const Edge** current);
91 void link_with_existing_chain(const StoredEdge* current_stored, StoredEdge** previous, size_t previous_length);
92
93 template <typename T>
94 void iterate(T& functor) const { _edges->iterate_value<T>(functor); }
95
96 DEBUG_ONLY(bool contains(const oop* reference) const;)
97
98 public:
99 EdgeStore();
100 ~EdgeStore();
101
102 bool is_empty() const;
103 traceid get_id(const Edge* edge) const;
104 void put_chain(const Edge* chain, size_t length);
105 };
106
107 #endif // SHARE_VM_LEAKPROFILER_CHAINS_EDGESTORE_HPP