1/*
2 * Copyright (c) 1998, 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 "ci/ciEnv.hpp"
27#include "ci/ciInstance.hpp"
28#include "ci/ciMetadata.hpp"
29#include "code/oopRecorder.inline.hpp"
30#include "memory/allocation.inline.hpp"
31#include "oops/oop.inline.hpp"
32#include "runtime/jniHandles.inline.hpp"
33#include "utilities/copy.hpp"
34
35#ifdef ASSERT
36template <class T> int ValueRecorder<T>::_find_index_calls = 0;
37template <class T> int ValueRecorder<T>::_hit_indexes = 0;
38template <class T> int ValueRecorder<T>::_missed_indexes = 0;
39#endif //ASSERT
40
41
42template <class T> ValueRecorder<T>::ValueRecorder(Arena* arena) {
43 _handles = NULL;
44 _indexes = NULL;
45 _arena = arena;
46 _complete = false;
47}
48
49template <class T> template <class X> ValueRecorder<T>::IndexCache<X>::IndexCache() {
50 assert(first_index > 0, "initial zero state of cache must be invalid index");
51 Copy::zero_to_bytes(&_cache[0], sizeof(_cache));
52}
53
54template <class T> int ValueRecorder<T>::size() {
55 _complete = true;
56 if (_handles == NULL) return 0;
57 return _handles->length() * sizeof(T);
58}
59
60template <class T> void ValueRecorder<T>::copy_values_to(nmethod* nm) {
61 assert(_complete, "must be frozen");
62 maybe_initialize(); // get non-null handles, even if we have no oops
63 nm->copy_values(_handles);
64}
65
66template <class T> void ValueRecorder<T>::maybe_initialize() {
67 if (_handles == NULL) {
68 if (_arena != NULL) {
69 _handles = new(_arena) GrowableArray<T>(_arena, 10, 0, 0);
70 _no_finds = new(_arena) GrowableArray<int>( _arena, 10, 0, 0);
71 } else {
72 _handles = new GrowableArray<T>(10, 0, 0);
73 _no_finds = new GrowableArray<int>( 10, 0, 0);
74 }
75 }
76}
77
78
79template <class T> T ValueRecorder<T>::at(int index) {
80 // there is always a NULL virtually present as first object
81 if (index == null_index) return NULL;
82 return _handles->at(index - first_index);
83}
84
85
86template <class T> int ValueRecorder<T>::add_handle(T h, bool make_findable) {
87 assert(!_complete, "cannot allocate more elements after size query");
88 maybe_initialize();
89 // indexing uses 1 as an origin--0 means null
90 int index = _handles->length() + first_index;
91 _handles->append(h);
92
93 // Support correct operation of find_index().
94 assert(!(make_findable && !is_real(h)), "nulls are not findable");
95 if (make_findable) {
96 // This index may be returned from find_index().
97 if (_indexes != NULL) {
98 int* cloc = _indexes->cache_location(h);
99 _indexes->set_cache_location_index(cloc, index);
100 } else if (index == index_cache_threshold && _arena != NULL) {
101 _indexes = new(_arena) IndexCache<T>();
102 for (int i = 0; i < _handles->length(); i++) {
103 // Load the cache with pre-existing elements.
104 int index0 = i + first_index;
105 if (_no_finds->contains(index0)) continue;
106 int* cloc = _indexes->cache_location(_handles->at(i));
107 _indexes->set_cache_location_index(cloc, index0);
108 }
109 }
110 } else if (is_real(h)) {
111 // Remember that this index is not to be returned from find_index().
112 // This case is rare, because most or all uses of allocate_index pass
113 // an argument of NULL or Universe::non_oop_word.
114 // Thus, the expected length of _no_finds is zero.
115 _no_finds->append(index);
116 }
117
118 return index;
119}
120
121
122template <class T> int ValueRecorder<T>::maybe_find_index(T h) {
123 debug_only(_find_index_calls++);
124 assert(!_complete, "cannot allocate more elements after size query");
125 maybe_initialize();
126 if (h == NULL) return null_index;
127 assert(is_real(h), "must be valid");
128 int* cloc = (_indexes == NULL)? NULL: _indexes->cache_location(h);
129 if (cloc != NULL) {
130 int cindex = _indexes->cache_location_index(cloc);
131 if (cindex == 0) {
132 return -1; // We know this handle is completely new.
133 }
134 if (cindex >= first_index && _handles->at(cindex - first_index) == h) {
135 debug_only(_hit_indexes++);
136 return cindex;
137 }
138 if (!_indexes->cache_location_collision(cloc)) {
139 return -1; // We know the current cache occupant is unique to that cloc.
140 }
141 }
142
143 // Not found in cache, due to a cache collision. (Or, no cache at all.)
144 // Do a linear search, most recent to oldest.
145 for (int i = _handles->length() - 1; i >= 0; i--) {
146 if (_handles->at(i) == h) {
147 int findex = i + first_index;
148 if (_no_finds->contains(findex)) continue; // oops; skip this one
149 if (cloc != NULL) {
150 _indexes->set_cache_location_index(cloc, findex);
151 }
152 debug_only(_missed_indexes++);
153 return findex;
154 }
155 }
156 return -1;
157}
158
159// Explicitly instantiate these types
160template class ValueRecorder<Metadata*>;
161template class ValueRecorder<jobject>;
162
163oop ObjectLookup::ObjectEntry::oop_value() const { return JNIHandles::resolve(_value); }
164
165ObjectLookup::ObjectLookup(): _values(4), _gc_count(Universe::heap()->total_collections()) {}
166
167void ObjectLookup::maybe_resort() {
168 // The values are kept sorted by address which may be invalidated
169 // after a GC, so resort if a GC has occurred since last time.
170 if (_gc_count != Universe::heap()->total_collections()) {
171 _gc_count = Universe::heap()->total_collections();
172 _values.sort(sort_by_address);
173 }
174}
175
176int ObjectLookup::sort_by_address(oop a, oop b) {
177 // oopDesc::compare returns the opposite of what this function returned
178 return -(oopDesc::compare(a, b));
179}
180
181int ObjectLookup::sort_by_address(ObjectEntry* a, ObjectEntry* b) {
182 return sort_by_address(a->oop_value(), b->oop_value());
183}
184
185int ObjectLookup::sort_oop_by_address(oop const& a, ObjectEntry const& b) {
186 return sort_by_address(a, b.oop_value());
187}
188
189int ObjectLookup::find_index(jobject handle, OopRecorder* oop_recorder) {
190 if (handle == NULL) {
191 return 0;
192 }
193 oop object = JNIHandles::resolve(handle);
194 maybe_resort();
195 bool found;
196 int location = _values.find_sorted<oop, sort_oop_by_address>(object, found);
197 if (!found) {
198 jobject handle = JNIHandles::make_local(object);
199 ObjectEntry r(handle, oop_recorder->allocate_oop_index(handle));
200 _values.insert_before(location, r);
201 return r.index();
202 }
203 return _values.at(location).index();
204}
205