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