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>;