1 /*
2 * Copyright (c) 1998, 2012, 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.hpp"
30 #include "memory/allocation.inline.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "utilities/copy.hpp"
33
34 #ifdef ASSERT
35 template <class T> int ValueRecorder<T>::_find_index_calls = 0;
36 template <class T> int ValueRecorder<T>::_hit_indexes = 0;
37 template <class T> int ValueRecorder<T>::_missed_indexes = 0;
38 #endif //ASSERT
39
40
41 template <class T> ValueRecorder<T>::ValueRecorder(Arena* arena) {
42 _handles = NULL;
43 _indexes = NULL;
44 _arena = arena;
45 _complete = false;
46 }
47
48 template <class T> template <class X> ValueRecorder<T>::IndexCache<X>::IndexCache() {
49 assert(first_index > 0, "initial zero state of cache must be invalid index");
50 Copy::zero_to_bytes(&_cache[0], sizeof(_cache));
51 }
52
53 template <class T> int ValueRecorder<T>::size() {
54 _complete = true;
55 if (_handles == NULL) return 0;
56 return _handles->length() * sizeof(T);
57 }
58
59 template <class T> void ValueRecorder<T>::copy_values_to(nmethod* nm) {
60 assert(_complete, "must be frozen");
61 maybe_initialize(); // get non-null handles, even if we have no oops
62 nm->copy_values(_handles);
63 }
64
65 template <class T> void ValueRecorder<T>::maybe_initialize() {
66 if (_handles == NULL) {
67 if (_arena != NULL) {
68 _handles = new(_arena) GrowableArray<T>(_arena, 10, 0, 0);
69 _no_finds = new(_arena) GrowableArray<int>( _arena, 10, 0, 0);
70 } else {
71 _handles = new GrowableArray<T>(10, 0, 0);
72 _no_finds = new GrowableArray<int>( 10, 0, 0);
73 }
74 }
75 }
76
77
78 template <class T> T ValueRecorder<T>::at(int index) {
79 // there is always a NULL virtually present as first object
80 if (index == null_index) return NULL;
81 return _handles->at(index - first_index);
82 }
83
84
85 template <class T> int ValueRecorder<T>::add_handle(T h, bool make_findable) {
86 assert(!_complete, "cannot allocate more elements after size query");
87 maybe_initialize();
88 // indexing uses 1 as an origin--0 means null
89 int index = _handles->length() + first_index;
90 _handles->append(h);
91
92 // Support correct operation of find_index().
93 assert(!(make_findable && !is_real(h)), "nulls are not findable");
94 if (make_findable) {
95 // This index may be returned from find_index().
96 if (_indexes != NULL) {
97 int* cloc = _indexes->cache_location(h);
98 _indexes->set_cache_location_index(cloc, index);
99 } else if (index == index_cache_threshold && _arena != NULL) {
100 _indexes = new(_arena) IndexCache<T>();
101 for (int i = 0; i < _handles->length(); i++) {
102 // Load the cache with pre-existing elements.
103 int index0 = i + first_index;
104 if (_no_finds->contains(index0)) continue;
105 int* cloc = _indexes->cache_location(_handles->at(i));
106 _indexes->set_cache_location_index(cloc, index0);
107 }
108 }
109 } else if (is_real(h)) {
110 // Remember that this index is not to be returned from find_index().
111 // This case is rare, because most or all uses of allocate_index pass
112 // an argument of NULL or Universe::non_oop_word.
113 // Thus, the expected length of _no_finds is zero.
114 _no_finds->append(index);
115 }
116
117 return index;
118 }
119
120
121 template <class T> int ValueRecorder<T>::maybe_find_index(T h) {
122 debug_only(_find_index_calls++);
123 assert(!_complete, "cannot allocate more elements after size query");
124 maybe_initialize();
125 if (h == NULL) return null_index;
126 assert(is_real(h), "must be valid");
127 int* cloc = (_indexes == NULL)? NULL: _indexes->cache_location(h);
128 if (cloc != NULL) {
129 int cindex = _indexes->cache_location_index(cloc);
130 if (cindex == 0) {
131 return -1; // We know this handle is completely new.
132 }
133 if (cindex >= first_index && _handles->at(cindex - first_index) == h) {
134 debug_only(_hit_indexes++);
135 return cindex;
136 }
137 if (!_indexes->cache_location_collision(cloc)) {
138 return -1; // We know the current cache occupant is unique to that cloc.
139 }
140 }
141
142 // Not found in cache, due to a cache collision. (Or, no cache at all.)
143 // Do a linear search, most recent to oldest.
144 for (int i = _handles->length() - 1; i >= 0; i--) {
145 if (_handles->at(i) == h) {
146 int findex = i + first_index;
147 if (_no_finds->contains(findex)) continue; // oops; skip this one
148 if (cloc != NULL) {
149 _indexes->set_cache_location_index(cloc, findex);
150 }
151 debug_only(_missed_indexes++);
152 return findex;
153 }
154 }
155 return -1;
156 }
157
158 // Explicitly instantiate these types
159 template class ValueRecorder<Metadata*>;
160 template class ValueRecorder<jobject>;