1 /* 2 * Copyright (c) 1998, 2010, 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 "code/oopRecorder.hpp" 27 #include "memory/allocation.inline.hpp" 28 #include "oops/oop.inline.hpp" 29 30 #ifdef ASSERT 31 int OopRecorder::_find_index_calls = 0; 32 int OopRecorder::_hit_indexes = 0; 33 int OopRecorder::_missed_indexes = 0; 34 #endif //ASSERT 35 36 37 OopRecorder::OopRecorder(Arena* arena) { 38 _handles = NULL; 39 _indexes = NULL; 40 _arena = arena; 41 _complete = false; 42 } 43 44 OopRecorder::IndexCache::IndexCache() { 45 assert(first_index > 0, "initial zero state of cache must be invalid index"); 46 Copy::zero_to_bytes(&_cache[0], sizeof(_cache)); 47 } 48 49 int OopRecorder::oop_size() { 50 _complete = true; 51 if (_handles == NULL) return 0; 52 return _handles->length() * sizeof(oop); 53 } 54 55 void OopRecorder::copy_to(nmethod* nm) { 56 assert(_complete, "must be frozen"); 57 maybe_initialize(); // get non-null handles, even if we have no oops 58 nm->copy_oops(_handles); 59 } 60 61 void OopRecorder::maybe_initialize() { 62 if (_handles == NULL) { 63 if (_arena != NULL) { 64 _handles = new(_arena) GrowableArray<jobject>(_arena, 10, 0, 0); 65 _no_finds = new(_arena) GrowableArray<int>( _arena, 10, 0, 0); 66 } else { 67 _handles = new GrowableArray<jobject>(10, 0, 0); 68 _no_finds = new GrowableArray<int>( 10, 0, 0); 69 } 70 } 71 } 72 73 74 jobject OopRecorder::handle_at(int index) { 75 // there is always a NULL virtually present as first object 76 if (index == null_index) return NULL; 77 return _handles->at(index - first_index); 78 } 79 80 81 // Local definition. Used only in this module. 82 inline bool OopRecorder::is_real_jobject(jobject h) { 83 return h != NULL && h != (jobject)Universe::non_oop_word(); 84 } 85 86 87 int OopRecorder::add_handle(jobject h, bool make_findable) { 88 assert(!_complete, "cannot allocate more elements after size query"); 89 maybe_initialize(); 90 // indexing uses 1 as an origin--0 means null 91 int index = _handles->length() + first_index; 92 _handles->append(h); 93 94 // Support correct operation of find_index(). 95 assert(!(make_findable && !is_real_jobject(h)), "nulls are not findable"); 96 if (make_findable) { 97 // This index may be returned from find_index(). 98 if (_indexes != NULL) { 99 int* cloc = _indexes->cache_location(h); 100 _indexes->set_cache_location_index(cloc, index); 101 } else if (index == index_cache_threshold && _arena != NULL) { 102 _indexes = new(_arena) IndexCache(); 103 for (int i = 0; i < _handles->length(); i++) { 104 // Load the cache with pre-existing elements. 105 int index0 = i + first_index; 106 if (_no_finds->contains(index0)) continue; 107 int* cloc = _indexes->cache_location(_handles->at(i)); 108 _indexes->set_cache_location_index(cloc, index0); 109 } 110 } 111 } else if (is_real_jobject(h)) { 112 // Remember that this index is not to be returned from find_index(). 113 // This case is rare, because most or all uses of allocate_index pass 114 // a jobject argument of NULL or Universe::non_oop_word. 115 // Thus, the expected length of _no_finds is zero. 116 _no_finds->append(index); 117 } 118 119 return index; 120 } 121 122 123 int OopRecorder::maybe_find_index(jobject h) { 124 debug_only(_find_index_calls++); 125 assert(!_complete, "cannot allocate more elements after size query"); 126 maybe_initialize(); 127 if (h == NULL) return null_index; 128 assert(is_real_jobject(h), "must be valid jobject"); 129 int* cloc = (_indexes == NULL)? NULL: _indexes->cache_location(h); 130 if (cloc != NULL) { 131 int cindex = _indexes->cache_location_index(cloc); 132 if (cindex == 0) { 133 return -1; // We know this handle is completely new. 134 } 135 if (cindex >= first_index && _handles->at(cindex - first_index) == h) { 136 debug_only(_hit_indexes++); 137 return cindex; 138 } 139 if (!_indexes->cache_location_collision(cloc)) { 140 return -1; // We know the current cache occupant is unique to that cloc. 141 } 142 } 143 144 // Not found in cache, due to a cache collision. (Or, no cache at all.) 145 // Do a linear search, most recent to oldest. 146 for (int i = _handles->length() - 1; i >= 0; i--) { 147 if (_handles->at(i) == h) { 148 int findex = i + first_index; 149 if (_no_finds->contains(findex)) continue; // oops; skip this one 150 if (cloc != NULL) { 151 _indexes->set_cache_location_index(cloc, findex); 152 } 153 debug_only(_missed_indexes++); 154 return findex; 155 } 156 } 157 return -1; 158 }