1 /*
2 * Copyright (c) 2014, 2021, 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_JFR_LEAKPROFILER_CHAINS_EDGESTORE_HPP
26 #define SHARE_JFR_LEAKPROFILER_CHAINS_EDGESTORE_HPP
27
28 #include "jfr/leakprofiler/chains/edge.hpp"
29 #include "jfr/leakprofiler/utilities/unifiedOopRef.hpp"
30 #include "jfr/utilities/jfrHashtable.hpp"
31 #include "memory/allocation.hpp"
32
33 typedef u8 traceid;
34 class ObjectSample;
35
36 class StoredEdge : public Edge {
37 private:
38 mutable traceid _gc_root_id;
39 size_t _skip_length;
40
41 public:
42 StoredEdge();
43 StoredEdge(const Edge* parent, UnifiedOopRef reference);
44 StoredEdge(const Edge& edge);
45 StoredEdge(const StoredEdge& edge);
46
47 traceid gc_root_id() const { return _gc_root_id; }
48 void set_gc_root_id(traceid root_id) const { _gc_root_id = root_id; }
49
50 bool is_skip_edge() const { return _skip_length != 0; }
51 size_t skip_length() const { return _skip_length; }
52 void set_skip_length(size_t length) { _skip_length = length; }
53
54 void set_parent(const Edge* edge) { this->_parent = edge; }
55
56 StoredEdge* parent() const {
57 return const_cast<StoredEdge*>(static_cast<const StoredEdge*>(Edge::parent()));
58 }
59 };
60
61 class EdgeStore : public CHeapObj<mtTracing> {
62 typedef HashTableHost<StoredEdge, traceid, JfrHashtableEntry, EdgeStore> EdgeHashTable;
63 typedef EdgeHashTable::HashEntry EdgeEntry;
64 template <typename,
65 typename,
66 template<typename, typename> class,
67 typename,
68 size_t>
69 friend class HashTableHost;
70 friend class EventEmitter;
71 friend class ObjectSampleWriter;
72 friend class ObjectSampleCheckpoint;
73 private:
74 static traceid _edge_id_counter;
75 EdgeHashTable* _edges;
76
77 // Hash table callbacks
78 void on_link(EdgeEntry* entry);
79 bool on_equals(uintptr_t hash, const EdgeEntry* entry);
80 void on_unlink(EdgeEntry* entry);
81
82 StoredEdge* get(UnifiedOopRef reference) const;
83 const StoredEdge* get(const ObjectSample* sample) const;
84 StoredEdge* put(UnifiedOopRef reference);
85 traceid gc_root_id(const Edge* edge) const;
86
87 bool put_edges(StoredEdge** previous, const Edge** current, size_t length);
88 bool put_skip_edge(StoredEdge** previous, const Edge** current, size_t distance_to_root);
89 void put_chain_epilogue(StoredEdge* leak_context_edge, const Edge* root) const;
90
91 StoredEdge* associate_leak_context_with_candidate(const Edge* edge);
92 void store_gc_root_id_in_leak_context_edge(StoredEdge* leak_context_edge, const Edge* root) const;
93 StoredEdge* link_new_edge(StoredEdge** previous, const Edge** current);
94 void link_with_existing_chain(const StoredEdge* current_stored, StoredEdge** previous, size_t previous_length);
95 bool has_leak_context(const ObjectSample* sample) const;
96
97 template <typename T>
98 void iterate(T& functor) const { _edges->iterate_value<T>(functor); }
99
100 DEBUG_ONLY(bool contains(UnifiedOopRef reference) const;)
101
102 public:
103 EdgeStore();
104 ~EdgeStore();
105
106 bool is_empty() const;
107 traceid get_id(const Edge* edge) const;
108 void put_chain(const Edge* chain, size_t length);
109 };
110
111 #endif // SHARE_JFR_LEAKPROFILER_CHAINS_EDGESTORE_HPP