Thu, 22 Jul 2010 10:27:41 -0400
6962589: remove breadth first scanning code from parallel gc
Summary: Remove the breadth-first copying order from ParallelScavenge and use depth-first by default.
Reviewed-by: jcoomes, ysr, johnc
duke@435 | 1 | /* |
trims@1907 | 2 | * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
trims@1907 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
trims@1907 | 20 | * or visit www.oracle.com if you need additional information or have any |
trims@1907 | 21 | * questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
duke@435 | 25 | # include "incls/_precompiled.incl" |
duke@435 | 26 | # include "incls/_symbolKlass.cpp.incl" |
duke@435 | 27 | |
duke@435 | 28 | symbolOop symbolKlass::allocate_symbol(u1* name, int len, TRAPS) { |
duke@435 | 29 | // Don't allow symbol oops to be created which cannot fit in a symbolOop. |
duke@435 | 30 | if (len > symbolOopDesc::max_length()) { |
duke@435 | 31 | THROW_MSG_0(vmSymbols::java_lang_InternalError(), |
duke@435 | 32 | "name is too long to represent"); |
duke@435 | 33 | } |
duke@435 | 34 | int size = symbolOopDesc::object_size(len); |
duke@435 | 35 | symbolKlassHandle h_k(THREAD, as_klassOop()); |
duke@435 | 36 | symbolOop sym = (symbolOop) |
duke@435 | 37 | CollectedHeap::permanent_obj_allocate(h_k, size, CHECK_NULL); |
duke@435 | 38 | assert(!sym->is_parsable(), "not expecting parsability yet."); |
duke@435 | 39 | No_Safepoint_Verifier no_safepoint; |
duke@435 | 40 | sym->set_utf8_length(len); |
duke@435 | 41 | for (int i = 0; i < len; i++) { |
duke@435 | 42 | sym->byte_at_put(i, name[i]); |
duke@435 | 43 | } |
duke@435 | 44 | // Let the first emptySymbol be created and |
duke@435 | 45 | // ensure only one is ever created. |
duke@435 | 46 | assert(sym->is_parsable() || Universe::emptySymbol() == NULL, |
duke@435 | 47 | "should be parsable here."); |
duke@435 | 48 | return sym; |
duke@435 | 49 | } |
duke@435 | 50 | |
duke@435 | 51 | bool symbolKlass::allocate_symbols(int names_count, const char** names, |
duke@435 | 52 | int* lengths, symbolOop* sym_oops, TRAPS) { |
duke@435 | 53 | if (UseConcMarkSweepGC || UseParallelGC) { |
duke@435 | 54 | // Concurrent GC needs to mark all the allocated symbol oops after |
duke@435 | 55 | // the remark phase which isn't done below (except the first symbol oop). |
duke@435 | 56 | // So return false which will let the symbols be allocated one by one. |
duke@435 | 57 | // The parallel collector uses an object start array to find the |
duke@435 | 58 | // start of objects on a dirty card. The object start array is not |
duke@435 | 59 | // updated for the start of each symbol so is not precise. During |
duke@435 | 60 | // object array verification this causes a verification failure. |
duke@435 | 61 | // In a product build this causes extra searching for the start of |
duke@435 | 62 | // a symbol. As with the concurrent collector a return of false will |
duke@435 | 63 | // cause each symbol to be allocated separately and in the case |
duke@435 | 64 | // of the parallel collector will cause the object |
duke@435 | 65 | // start array to be updated. |
duke@435 | 66 | return false; |
duke@435 | 67 | } |
duke@435 | 68 | |
duke@435 | 69 | assert(names_count > 0, "can't allocate 0 symbols"); |
duke@435 | 70 | |
duke@435 | 71 | int total_size = 0; |
duke@435 | 72 | int i, sizes[SymbolTable::symbol_alloc_batch_size]; |
duke@435 | 73 | for (i=0; i<names_count; i++) { |
duke@435 | 74 | int len = lengths[i]; |
duke@435 | 75 | if (len > symbolOopDesc::max_length()) { |
duke@435 | 76 | return false; |
duke@435 | 77 | } |
duke@435 | 78 | int sz = symbolOopDesc::object_size(len); |
duke@435 | 79 | sizes[i] = sz * HeapWordSize; |
duke@435 | 80 | total_size += sz; |
duke@435 | 81 | } |
duke@435 | 82 | symbolKlassHandle h_k(THREAD, as_klassOop()); |
duke@435 | 83 | HeapWord* base = Universe::heap()->permanent_mem_allocate(total_size); |
duke@435 | 84 | if (base == NULL) { |
duke@435 | 85 | return false; |
duke@435 | 86 | } |
duke@435 | 87 | |
duke@435 | 88 | // CAN'T take any safepoint during the initialization of the symbol oops ! |
duke@435 | 89 | No_Safepoint_Verifier nosafepoint; |
duke@435 | 90 | |
duke@435 | 91 | klassOop sk = h_k(); |
duke@435 | 92 | int pos = 0; |
duke@435 | 93 | for (i=0; i<names_count; i++) { |
duke@435 | 94 | symbolOop s = (symbolOop) (((char*)base) + pos); |
duke@435 | 95 | s->set_mark(markOopDesc::prototype()); |
duke@435 | 96 | s->set_klass(sk); |
duke@435 | 97 | s->set_utf8_length(lengths[i]); |
duke@435 | 98 | const char* name = names[i]; |
duke@435 | 99 | for (int j=0; j<lengths[i]; j++) { |
duke@435 | 100 | s->byte_at_put(j, name[j]); |
duke@435 | 101 | } |
duke@435 | 102 | |
duke@435 | 103 | assert(s->is_parsable(), "should be parsable here."); |
duke@435 | 104 | |
duke@435 | 105 | sym_oops[i] = s; |
duke@435 | 106 | pos += sizes[i]; |
duke@435 | 107 | } |
duke@435 | 108 | return true; |
duke@435 | 109 | } |
duke@435 | 110 | |
duke@435 | 111 | klassOop symbolKlass::create_klass(TRAPS) { |
duke@435 | 112 | symbolKlass o; |
duke@435 | 113 | KlassHandle h_this_klass(THREAD, Universe::klassKlassObj()); |
duke@435 | 114 | KlassHandle k = base_create_klass(h_this_klass, header_size(), o.vtbl_value(), CHECK_NULL); |
duke@435 | 115 | // Make sure size calculation is right |
duke@435 | 116 | assert(k()->size() == align_object_size(header_size()), "wrong size for object"); |
duke@435 | 117 | // java_lang_Class::create_mirror(k, CHECK_NULL); // Allocate mirror |
duke@435 | 118 | return k(); |
duke@435 | 119 | } |
duke@435 | 120 | |
duke@435 | 121 | int symbolKlass::oop_size(oop obj) const { |
duke@435 | 122 | assert(obj->is_symbol(),"must be a symbol"); |
duke@435 | 123 | symbolOop s = symbolOop(obj); |
duke@435 | 124 | int size = s->object_size(); |
duke@435 | 125 | return size; |
duke@435 | 126 | } |
duke@435 | 127 | |
duke@435 | 128 | bool symbolKlass::oop_is_parsable(oop obj) const { |
duke@435 | 129 | assert(obj->is_symbol(),"must be a symbol"); |
duke@435 | 130 | symbolOop s = symbolOop(obj); |
duke@435 | 131 | return s->object_is_parsable(); |
duke@435 | 132 | } |
duke@435 | 133 | |
duke@435 | 134 | void symbolKlass::oop_follow_contents(oop obj) { |
duke@435 | 135 | assert (obj->is_symbol(), "object must be symbol"); |
duke@435 | 136 | // Performance tweak: We skip iterating over the klass pointer since we |
duke@435 | 137 | // know that Universe::symbolKlassObj never moves. |
duke@435 | 138 | // Note: do not follow next link here (see SymbolTable::follow_contents) |
duke@435 | 139 | } |
duke@435 | 140 | |
duke@435 | 141 | #ifndef SERIALGC |
duke@435 | 142 | void symbolKlass::oop_follow_contents(ParCompactionManager* cm, oop obj) { |
duke@435 | 143 | assert (obj->is_symbol(), "object must be symbol"); |
duke@435 | 144 | // Performance tweak: We skip iterating over the klass pointer since we |
duke@435 | 145 | // know that Universe::symbolKlassObj never moves. |
duke@435 | 146 | // Note: do not follow next link here (see SymbolTable::follow_contents) |
duke@435 | 147 | } |
duke@435 | 148 | #endif // SERIALGC |
duke@435 | 149 | |
duke@435 | 150 | int symbolKlass::oop_oop_iterate(oop obj, OopClosure* blk) { |
duke@435 | 151 | assert(obj->is_symbol(), "object must be symbol"); |
duke@435 | 152 | symbolOop s = symbolOop(obj); |
duke@435 | 153 | // Get size before changing pointers. |
duke@435 | 154 | // Don't call size() or oop_size() since that is a virtual call. |
duke@435 | 155 | int size = s->object_size(); |
duke@435 | 156 | // Performance tweak: We skip iterating over the klass pointer since we |
duke@435 | 157 | // know that Universe::symbolKlassObj never moves. |
duke@435 | 158 | return size; |
duke@435 | 159 | } |
duke@435 | 160 | |
duke@435 | 161 | |
duke@435 | 162 | int symbolKlass::oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) { |
duke@435 | 163 | assert(obj->is_symbol(), "object must be symbol"); |
duke@435 | 164 | symbolOop s = symbolOop(obj); |
duke@435 | 165 | // Get size before changing pointers. |
duke@435 | 166 | // Don't call size() or oop_size() since that is a virtual call. |
duke@435 | 167 | int size = s->object_size(); |
duke@435 | 168 | // Performance tweak: We skip iterating over the klass pointer since we |
duke@435 | 169 | // know that Universe::symbolKlassObj never moves. |
duke@435 | 170 | return size; |
duke@435 | 171 | } |
duke@435 | 172 | |
duke@435 | 173 | |
duke@435 | 174 | int symbolKlass::oop_adjust_pointers(oop obj) { |
duke@435 | 175 | assert(obj->is_symbol(), "should be symbol"); |
duke@435 | 176 | symbolOop s = symbolOop(obj); |
duke@435 | 177 | // Get size before changing pointers. |
duke@435 | 178 | // Don't call size() or oop_size() since that is a virtual call. |
duke@435 | 179 | int size = s->object_size(); |
duke@435 | 180 | // Performance tweak: We skip iterating over the klass pointer since we |
duke@435 | 181 | // know that Universe::symbolKlassObj never moves. |
duke@435 | 182 | return size; |
duke@435 | 183 | } |
duke@435 | 184 | |
duke@435 | 185 | |
duke@435 | 186 | #ifndef SERIALGC |
duke@435 | 187 | void symbolKlass::oop_push_contents(PSPromotionManager* pm, oop obj) { |
duke@435 | 188 | assert(obj->is_symbol(), "should be symbol"); |
duke@435 | 189 | } |
duke@435 | 190 | |
duke@435 | 191 | int symbolKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) { |
duke@435 | 192 | assert(obj->is_symbol(), "should be symbol"); |
duke@435 | 193 | return symbolOop(obj)->object_size(); |
duke@435 | 194 | } |
duke@435 | 195 | |
duke@435 | 196 | int symbolKlass::oop_update_pointers(ParCompactionManager* cm, oop obj, |
duke@435 | 197 | HeapWord* beg_addr, HeapWord* end_addr) { |
duke@435 | 198 | assert(obj->is_symbol(), "should be symbol"); |
duke@435 | 199 | return symbolOop(obj)->object_size(); |
duke@435 | 200 | } |
duke@435 | 201 | #endif // SERIALGC |
duke@435 | 202 | |
duke@435 | 203 | #ifndef PRODUCT |
duke@435 | 204 | // Printing |
duke@435 | 205 | |
duke@435 | 206 | void symbolKlass::oop_print_on(oop obj, outputStream* st) { |
duke@435 | 207 | st->print("Symbol: '"); |
never@657 | 208 | symbolOop(obj)->print_symbol_on(st); |
duke@435 | 209 | st->print("'"); |
duke@435 | 210 | } |
duke@435 | 211 | |
jrose@1590 | 212 | #endif //PRODUCT |
jrose@1590 | 213 | |
duke@435 | 214 | void symbolKlass::oop_print_value_on(oop obj, outputStream* st) { |
duke@435 | 215 | symbolOop sym = symbolOop(obj); |
duke@435 | 216 | st->print("'"); |
duke@435 | 217 | for (int i = 0; i < sym->utf8_length(); i++) { |
duke@435 | 218 | st->print("%c", sym->byte_at(i)); |
duke@435 | 219 | } |
duke@435 | 220 | st->print("'"); |
duke@435 | 221 | } |
duke@435 | 222 | |
duke@435 | 223 | const char* symbolKlass::internal_name() const { |
duke@435 | 224 | return "{symbol}"; |
duke@435 | 225 | } |